Heathkit SB-104 Mixed manual

Operation

of

the

SINGLE

MODEL

SB-704-1

SIDEBAND

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TRANSCEIVER

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BENTON

HEATH

HARBOR,

COMPANY

MICHIGAN

490

2

TABLEOFCONTENTS

TEST AND ADJUSTMENTS

FINAL ASSEMBLY INSTALLATION Circuit Board Service Policy

Fixed Station Installation Mobile Station Installation OPERATION Control Functions

Tune-up

Receiving

Transmitting TROUBLESHOOTING

Introduction

~~~~~i~~

VFO~B~~~~~

R~~~~~~~

Transmitter Troubleshooting Guide Display Troubleshooting Guide

Voltage and Continuity Checks Test Checking Transistors and Diodes

MAINTENANCE Circuit Board Schematic Index Pin-out Diagrams

......................

.....................

....................

the

T~~~~~~

~~~~bl~~h~~~~~~

T~~~~~~~~~~~~~~

Chart

.....................

................

.................

...............

.............

................

............

.............

............

id^

.........

...........

.........

...........

............

233 Identification Charts 247 VFO and Buffer Circuit Boards

249 Converter Circuit Boards 251 Display Circuit Board

/+

Counter C~rcuit Board 257 HFOIPremixer Circuit Board 259 g Transmitter AudioIReg C~rcuit Board 260 C Transmitter IF Circuit Board

261

driver

-

263

ck3

264

E

2c4 G~eceiver Front End Circu~t Board 266 F Receiver IFIAudio Circuit Board

268[di~ower Amplifier Circuit Board 270

272

273

274 275 INTERCONNECTIONS (fold-outfrom page)

275 WARRANTY

276

Circuit Board

VFO Filter Circuit Board

ALCIOUTPUT

Carrier GenIXtal Filter Circuit Board

SPEC~F~CAT~ONS THEORY

CHASSIS PHOTOGRAPHS 321

FUNCTIONS

circuit Board

OF

OPERATION

AND

.............

CUSTOMER

SERVICE

................

...............

...........

................

.................

CHASSIS

.........

279

...........

.............

..............

............

........

............

..............

............

.........

..........

...........

............

.............

281 281 286

288 291

294 296 298 300

302

304

306

308

310

312

315

319

.............

....

Inside front cover

Inside rear cover

327

.?,

TEST AND ADJUSTMENTS

The only circuit boards which should be connected or

installed at this time are: the display circuit board on the back of the front panel, the the chassis, and the circuitboards Converter assemblies. The remaining circuit boards will be installed as part of the"~est and Adjustment" section.

If you do not get the expected results after you insert each circuit board, refer to the boxed "Possible Cause Chart" which follows. If none of the difficulties listed of the malfunction, refer to the appropriate parts of the "Troubleshooting" and "Maintenance" sections. If you have

a

difficulty, DO NOT proceed until

in some cases, damage could result.

A push-to-talk switch, as found on most microphones, is a convenient way to key the transmitter in the following steps. If your microphone cord is not already wired to an

Amphenol 80MC2M connector (furnished),you should refer to Figure the necessary wiring diagram.

~~

2-6

in the Installation Section of this Manual for

~FOI~iiier circuit board under

?The -VFOAfhe

is

the cause

it

has been corrected

as.

IMPORTANT: After you install any one of the plug-in

circuit boards, carefully inspect both sides to be sure no

a

circuit board component touches could cause a short circuit.

metal shield, which

PUSHBUTTON OPERATION

The pushbuttons on switches following ways:

Push in to latch. Release by pushing again and quickly

1.

removing your finger. Example: the

2.

Push in to latch. Release by depressing another button in the same group. Example: the USB, group.

3.

To release a depressed button in another bunon in the same group until the depressed button releases.

S2

and S3 operate in me

ON

switch.

LSB, CW

a

group, gently

push

When a voltmeter is required, use a meter which has a high input impedance (one megohm or more).

Refer to Figure

1-2

for rear panel connections (fold-out from Page 237).

Refer to Figure

mounted on the chassis, and some adjustment locations.

If you have difficulty in removing a circuit board, use

screwdrivers in the board pullers as shown in Figure 1-3A.

1-1 for front panel locations and to Figure

1-3 to identify circuit boards, controls not

CHASSIS

Depress the 13.8 and the USB pushbuttons on the

(/)

front panel. All other pushbuttons should be released

(out).

(/I

Push the 11-pin socket on the power supply cable onto the PWR plug on the rear panel of the Transceiver. Make sure the keyway in the socket mates with the key on the plug.

( )

Connect the power supply to the electric outlet.

f

233

Page 234

rw=+

;nn*-lilm

(/I

Depress the ON button until it latches. The two pilot lamps should light and the meter should read half way

between 12 and 15 in

(/i

Depress the ALC button. The meter should read 0

Depress the PWR button. The meter should read

(

/i

Release the ON button. It will require a few seconds

for the power supply voltage to bleed down.

PSSIBLE CAUSE CHART

1.

Pilot lamps do not light. A.

Power supply switch at OFF position.

B. Power plug wired incorrectly.

C. Power cable from power supply wired

incorrectly.

D.

Defective power switch.

E.

In mobile installation, polarity of the power

supply leads reversed.

F. Defective power supply.

G.

01 or 02 installed incorrectly.

2.

Meter does not read 13.8 volts.

A.

Meter defective.

B. Meter switch wiring incorrect.

C. Chassis wiring incorrect.

--?

D.

E.

I

F. Supply voltage to Transceiver incorrect.

-

( )

Refer to F~gure 14 (fold-out from Page 237) and 28.0

prepare a 24" shielded cable. Lay

will be used later. 29.0

Cl

resistor across meter missing.

180 Shorting wire across meter terminals not removed.

TRANSMIT AUDIOIREGULATOR

Plug in circuit

(

I

j/

enters the two side guides properly and the way down.

=-(#-A

its

upper scale (13.8 volts).

th~s cable as~de. It

Make -sure it

is

0.

pushed all

-

POSSIBLE CAUSE CHART

1. Display does not light. A. No voltage at switch S3, section C, pin 6. B. Voltage at

missing.

C. Refer to the "Display Troubleshooting Chart"

(Page 288).

(/j

On the bottom of the chassis, connect the common lead of your voltmeter to the volts DC at

POSSIBLE CAUSE CHART

1. 5 or 11 volts incorrect. A. Chassis wiring. B. C. 01 or 02.

Turn the BAND switch and observe the first digit.

(JI

which should be blank (not lighted) or read 1 or depending upon the position of the BAND switch:

BAND FIRST SWITCH

3.5 Blank

1

7.0

14.0

21.0

WWV

28.5

29.5

POSSIBLE CAUSE CHART

The furst digit is incorrect.

1

A. B. BAND switch w~red incorrectly. C. BAND

term~nal A21 and 11 volts DC at 01.

IC202 or IC203.

IC156.

sw~tch turned 180".

"A"

on display board too low or

chass~s and measure 5

DIGIT

-

Blank

1

f

I

2.

(/I

Depress the ON button. The pilot lamps should light and the display should read

switch at 3.5. right end of the display should disappear.

FFFF.F

with the BAND

(J/

Depress the 100

Hz

button. The digit (letter) on the

~~='--*=.:**Ql

Page 235

POSSIBLE CAUSE CHART

The last digit does not disappear.

1. A. Switch defective.

B. Switch wired incorrectly.

(.

)

Connect your microphone to the MIC socket (see

Figure

connections).

(

,A

(,A

switch, short terminal 2 of the MIC connector to the chassis). You should hear a click and another click when vou release the switch and the

POSSIBLE CAUSE CHART

T/R relay does not pull in.

1. A. Relay.

5.

C.

Release the HI button.

( , )

Deprea the PTT switch. The relay should not operate

(/)

the HI button is depressed).

POSSIBLE CAUSE CHART

2-5 on Page 250 for microphone cable plug

Depress the HI button.

Depress the PTT (push-to-talk) switch on your microphone (if your microphone does not have a PTT

as

the relay closes,

replay opens.

Chassis wiring of the relay circuit. 0205,Q206.Q207, or Q208.

(the PTT switch should operate the relay only when

T/R relay operates in LO POWER position.

Check

wtrlng of LOIHI POWER sw~tch.

POSSIBLE CAUSE CHART

1.

VOX does not operate. A. Chassis wiring.

8. Q203,Q204. C. IC201.

0.

0203,D204,D205.

E. Microphone not properly wired for VOX

operation.

Depress the TUNE button. The relay should click as

(/j

closes. If diodes at BE.

(

/f

Release the TUNE button.

I/)

Close the relay with the PTT wkch. Terminal H1

should measure

(/

Release the PTT switch. The voltage should be

it

does not click, check the installation of the

P

1

lo

:

L

.7

volts.

-

POSSIBLE CAUSE CHART

at

HI

is

not

.7

Voltage

1. A.

Dl defective.

B.

TIR relay w~red incorrectly.

.

(/I

Release the ON button, and all other buttons.

-

,

I

The microphone can be removed, if desired.

COUNTER

(A

On card A, use your ohmmeter to check the resistance from the center conductor of JlOl to the ground foil.

If

the meter shows less than infinite

you must find the cause and correct

proceed.

volts.

(4

0.

resistance,

it

before you

it

Depress the VOX and the

(/I

(,/

Speak into the microphone and rotate the VOX GAIN control slowly clockwise until the relay operates.

Speak into the microphone end rotate the VOX

[/1

DELAY control slowly clockwise until the relay holds in for the desired length of time after you cease talking and then drops out (opens).

(A

Release the VOX button.

HI

buttons.

(

/Y

Plug in circu~t board A

Insert the phono plug (on the shielded lead coming

(/

)

from chaais cutout AA) through the rounded slot in the lateral shield circuit board.

NOTE: In the following steps, the BAND switch is still at

3.5.

(/i

Depress the ON button. The display should read

6600.0.

#85-14ELL

-.

--

-

Into phono socket JlOl on the

-

.

-

Page 236

( / )

Depress the US6 bunon. The display should read

6603.6. board. First, remove the

I/)

De~ress

"

6606.4.

Depress

6604.3.

POSSIBLE CAUSE CHART

1. Incorrect counter readout. A. Time base not running.

6. Chassis wiring.

C. Diodes

D.

E.

(/I

Release the ON button.

the

LSB button. The dis~lav should read

the

CW

Dl07 through 0110.

IC102. IC104, IC106. IC108, or IC110.

+5

VDC

is

low.

The

. .

display

should

read

NOTE: The high frequency oscillator coils will be adjusted in the following steps. Refer to Figure

inserting the alignment tool in the coil, and making a "flag" out of tape for the alignment tool so you can count the turns of the tool. Rotate the tool until the voltage peaks on the meter scale. Then rotate the tool as shown in the HFO

alignment chart.

J

ug circuit board

the left for which there are no sockets on board D.

~ ~

D (#B5-1418) into the extender

set

of extenderboaFd~piiin

1-6 for the method of

PRELIMINARY

Refer to Figure 1-3 (fold-out from Page 237) and

(,A

engage the VFO Level Adjust control through hole FY

in the side of the VFO assembly. Turn this control

fully counterclockwise.

HFO COIL

(,,"I

Plug the extender board (#85-1465) into compartment D.

VFO

OUTPUT ADJUSTMENT

ADJUSTMENT

II

SLUG

Figure

(A

Set your voltmeter on its lowest +DC scale. Connect

the meter common lead to the chassis and connect the other lead to the free lead of the 2200 resistor marked

(1)

Depress the ON button.

1-6

TP

(near Q402).

S2

vertical

Figure

NOTE: Refer to Figure

circuit boards into the extender board.

1-5

for

the method of plugging

(J

Adjurt each HFO coil as described in the following

chart. Before you adjust each coil for the peak voltage,

it

turn

slug clockwise for the peak voltage, which will be

typically 0.2 VDC to 0.5 VDC.

NOTE: The frequency display may be random during the

follow~ng adjustments.

counterclockwise to 0 volts. Then rotate the

~$DE+?

CWJh

b

BAND SWITCH

7

~-

14.0

-

~

..

21.0

-

28.0

-~

~~

.

28.5-

29.0

-

29.5

..

o:~

7

5,

6

'

:

1

7

j

2

B.Vi~hu

?,lR

LP

SFN~;

'

-.

try<

.

-.c,,<

2

1

1'3

2

1'6-

9's

2

2't

\

~'q

I

COIL

,.

.

NUMBER THEN ROTATE SLUG AS DESCRIBED.

L401 112 turn

.

L403

!

~406 1 turn

'

L407 1 turn CW L408

i

1409

i

ROTATE SLUG FOR

.-.~

1 turn

I/z

1

112turnCW

39

1 turn

1

I/L

*clockwise

..

CW*

CCWM*

turn CW

.~

~

CW-

-

turn

cw

turn CW

-.---

counterclockwise

PEAK

VOLT

j

.rrr.

.I12

.221

.7(?

13

z

.

12s

17q

VOLTAGE.

FFsn,,-,

1L3q7'7-6

22

f4i.VI

ZTa4r'36

z48qY'LB

36

qqs1zy

3t3qc'z-r

Page 237

1

,

:YYaL'7

.ira

-

.

Jj'7

r4Y

~.

In

4

-

~.

'SZ

-~~

,

826

.

-

.

I

UQ

~--..

FivN

4

cw

-

(z377.33

1

jq

oe'PY

2289r18(/

23aqr'+

zqd46

3689ZaL7

373qe1*6

(Z

-

..

I

POSSIBLE CAUSE CHART

HFO will not oscillate on one or more bands (meter

1.

remains at

A. BAN0 switch.

6.

C.

(1)

Release the ON button.

(4

Disconnect the voltmeter and remove board D from the extender board.

Remove the extender board.

(,

)

( )

Replace the extender board pln assembly removed

earl~er.

Plug board D into compartment D.

(,.

)

0).

Chassis wiring.

Refer to the HFOIpremix circuit board in the

maintenance section.

VFO OUTPUT ADJUSTMENT

(

)

Depress the ON button.

,

Turn the BAND switch to

I

,

.

I

Refer to Figure 1-3 (fold-out from Page 237) and engage the VFO adjustment control through hole FY in the side of the VFO assembly. Turn the control clockwise until the display becomes unstable. Then turn the control back until the display

(1)

Turn the BAND switch to 29.5 and check for display stability turn the control counterclockwise until the display is stable at both the 29.5 and band switch.

(+

or - one count). If the display

W.

is

WWV positions of the

stable.

is

unstable.

VFO FREQUENCY, SHIFT AND

I

LEVEL ADJUSTMENT

NOTES:

In the following step, if the alignment tool will not

1. engage the coil slug. screws on the bottom of the chassis and move the VFO forward. After the adjustment reposition the VFO and tighten the mounting screws.

The object of this adjustment

2. of the 3.5 band within the total VFO tuning range.

(

)

Turn the BAND switch to 3.5.

/

,

)

Depress the ON button.

)

Turn the MAlN TUNING knob until the display will

(

go no lower. If the display

right digit), repeat the VFO Output adjustment.

Remove the MAIN TUNING knob.

(

Insert the coil alignment

,

)

and into the corresponding hole in the VFO enclosure.

Fit the tool into the coil slug. Adjust the slug until the display reads approximately 3475.0. You may be able to see this display at two positions of the coil slug. When you have the correct position, the display will

read lower with counterclockwise rotation of the

alignment tool.

Reinstall the MAlN TUNING knob.

(,

)

(

)

Turn the MAIN TUNING knob until the frequency displayed remove the large knob.

( )

Depress the USB bunon and write down the

frequency displayed.

is

approximately 3800. Then temporarily

toosen the four VFO mounting

is

twl

is

completed,

is

to center the 500 kHz

then unstable (except the

into hole ET in the panel

I

!

Figure 1-3

Figure 1-3A

PREPARE EACH END

SHIELD LEAD

Figure 1-4

AS

SHOWN

SHIELD LEAD

Figure 1-1

Figure 1-2

,*

PATCH

OW,

."i

LUOII)

IPKR

Page 238

(,A'

Insert a small screwdriver into hole ES in the panel, and into the corresponding hole in the VFO enclosure. so the screwdriver engages the notch in the shaft of

C1211. the 15-60 pF trimmer on the oscillator board.

If the blade on your screwdriver is too large for the panel hole, you may be able to engage the trimmer

through the large knob hole.

(A

Depress the LSB button.

,

Adjust C1211 carefully until the LSB frequency display down, and the same frequency either the LSB or USB

screwdriver before taking the frequency reading.

is

the same as the US8 frequency you wrote

is

displayed when

is

depressed. Remove any metal

fGL**;*--***:**3J

Replace the knob and tighten both setscrews.

(/)

(4

Check the stablllty of the VFO frequency d~splay. If necessary, adjust the VFO level for a stable

BAND

sw~tch posltlons WWV and 29.5.

(j)

Check the stability of the frequency display at all positions of the BAND switch. If the display unstable on any band, perform the second step under "VFO Output Adjustment" on Page 237. Do not turn the control beyond the point where the display becomes stable.

(/)

Release the ON button.

d~splay at

is

1

I

POSSIBLE CAUSE CHART

The same frequency is not displayed in both LSB and

1. USB. A. FUNCTION switch wiring. B. Connector S01201.

C. DiodeD1201.

(,/I

To prevent light from shining through, place small pieces of black tape over holes ES and ET (the two knob and shaft forward VFO adjustment holes) on the back of the panel.

RECEIVER ALIGNMENT

Refer to Pictorial 12-37 (fold-out from Page 239) for the

following steps.

(J)

Turn the BAND switch to

Loosen the setscrew in the band switch shaft collar.

(, )

Refer to Detail 12-37A and pull the BAND switch

(,>

over the converter assembly.

3.5.

until the end of the shaft

is

I

-1

1

!

Detail

12-37A

1

rE=*7*"*=*:.*4

(A

Connect your station speaker to the SPKR phono socket on the rear panel.

(/)

Depress the ON button.

Page 239

I

i

'i

(1 Turn the

(/i

POSSIBLE CAUSE CHART

I

CONNECTOR

EDGE

Detail

Refer to Detail 12-378 and position BOTH switch

rotors on the

the flat sides of the openings are parallel to the connector edge of the board and so

notches point away from the connector edge.

ALCIfitr circuit board (#851425-1)

12-378

BOTH

index

1. No sound from speaker.

w

(/J

8.65

(,I

!-he ALCIfilter board into connector

of the converter assembly. Position the switch wafers on the side away from the front panel.

(,r

Carefully push the BAND switch knob toward the

front panel so the end of switch rotors on the

\\

tpyircvit boary~~y down

( )

Push the shaft collar snugly against the back of the

lateral

shield and tighten the setscrew against a flatted

side of the shaft.

)

Plug the

(

chassis cutout BL into the OUT and IN phono rockets

on the

Plug circuit board

OUT

ALCIfilter circuit board.

ALCIfilter circuit board. Position

and the IN coaxial cables coming from

E(#i?5-]463)

-~

its

shaft enters the two

as

required.

into its compartment.

K.

just back

.

(9

L/i

.

(A

'

Plug compartment. Transceiver.

cjm,

-

board G (#8514591 . into its board A. Then remove the circuit board from your

RF

GAlN knob fully clockwise.

Turn the AF GAlN knob. clockwise until you hear

noise from the speaker.

A. Speaker connections.

AF gain control connections.

B.

13.8V missing

C.

11V missing at pin 17 of board F.

D.

E.

Refer to Receiver IFIAudio troubleshooting guide.

Release the ON button.

MHz BANDPASS

Cut each lead of an 18 pF disc capacitor to 112".

at

19

FILTER

/cKu

1"

END

Figure

Refer to Fiaure

.

~~~

disc capacitor to the center conductor at the 112" end of the

24" shielded cable prepared earlier.

Remove the phono plug from socket JlOl on circuit

1-7

"

1-7

and solder one lead of the 18

.

of board

ALIGNMENT

F.

SOLDER

112"

END

1/2"

I

(INC

--

.-

DF

I

i

1

I

PICTORIAL

12-37

0

Figure

BOARD

E

MATCHING

TRIMMER TRIMMER

U

FlGH

END

1-8B

LOW

END

TRIMMER

BAND

SWITCH

Page 240

Refer to Figure 1-8A (fold-out from this page) and

(\j)

solder the free lead of the 18

pF capacitor to the foil strongest signal within one-half of a tuning knob designated TP on circuit board A. Solder the cable shield wires to the ground foil in the area shown.

(kl

Carefully ~lua board A back into

.

-

its

Look between the foil side of the circuit board and the shield to make sure the "hot" lead of the capacitor does not touch the shield.

(,%$'

Replace the phono plug in 5101.

(30

Remove circuit board G from theTransceiver.

Refer to Figure 1-86 and carefully unsolder from

()o

circuit board G the end of the jumper marked "this

end." Pull the end of the jumper out of the circuit board hole.

(H

Position the end of the center conductor of the shielded cable coming from circuit board A alongside the end of the jumper and solder the two together.

Use

a minimum amount of solder. Bend the shield

wires out of the way.

( )

Install the extender board in position

77

r\<>

A',:

<5.

.-,':,

(

)

Install circuit board G in the extender board.

(

)

Set the front panel controls as follows:

,$%,

G.

?,.W

Band Switch 3.5

1

RF Gain Fully clockwise ALC button Depressed

USB button Depressed AGC Fast

IMPORTANT: ALWAYS turn the Transceiver OFF before

you insert or remove a circuit board.

comoartment.

mtJ

'j

1,

( )

Tune the Tranxziver to 3500 kHz and select the

revolution.

(

)

Pull circuit board D up just enough to clear the

~lr

,

y

,..

t~

bP

.A

connectors on the board's bottom edge

Write

down

the

(

I

Push circuit board D back down onto

(

1

Tune the Transceiver to 4000 kHz and select the

S.meter

reading,

100

x:/5

ti",

its

I,",.':<

connectors.

strongest signal within one-half of a tuning knob

revolution.

( )

Pull circuit board D up just enough to clear the

connectors on the board's lower edge.

( )

Write down the S-meter reading.

)

Repeat the above procedures

(

at

3500 kHz and 4000

kHz and simultaneously adjust the trimmer capacitors

on coils L725 and L726 until the two

S-meter readings are as close together as you can conveniently get them. The readings will probably never coincide exactly. Two or three repetitions of the adjustment should be adequate.

(

)

Remove the shielded cable from the jumper on circuit

board G.

I

)

Reinstall the free end of the jumper on circuit board G in

its

former position (S-1).

NOTE: If you will perform the "Preselector Bandpass Filter Alignment" immediately, disregard the following two steps and leave the extender board and circuit board G in position G.

Remove circuit board G from the extender board and

( )

the extender board from position G.

( )

Depress the ON button.

(

1

Adjust the AF GAlN mntrol for a comfortable listening level.

\G

,;

!

(4:

:,

c,

.uc*4:,,

(

)

Tune the Transceiver to 3800 kHz. Then select the strongest signal within 5 kHz of this frequency.

When you perform any of the alignment steps in the remainder of this Manual, scale indication by adjustment of the control on circuit board Page 237). DO NOT use the RF

keep

the S-meter below a full

S-Meter Level Adjust

F

(see Figure 1-3, fold-out from

GAlN control for this

purpose.

(

)

Set the S-METER LEVEL ADJUST mntrol, (see

Figure

1-3, fold-out from Page 237) for an Smeter

reading of S9+50.

( )

Reinstall circuit board G in position

( )

Reinstall circuit board D.

G.

NOTE: The shielded cable connected to circuit board A will

be used in the

fotlowing bandpass filter alignment steps.

PRESELECTOR BANDPASS

FILTER ALIGNMENT

The object of this procedure for

a

uniform response across

is

used for each of the 80.40, 20, and 15 meter bands. Two

filters are used for the 10 meter band, one for the 28.0 and

28.5 band switch positions. and one for the 29.0 and 29.5 positions. The alignment of adjustment to a center

adjustments

at

the band edges. Although the band edge responses will not be exactly equal, they will be reasonably dose.

is

to adjust each bandpass filter

its

frequency range. One filter

a

filter calls for a coarse

ferquency, followed by equalizing

The following steps assume that the adjustment signal will be

furnished by the counter (circuit board A) and that the

S-meter will be used as a signal level indicator. You may be

a

able to improve the filter response to

small degree if you have a signal generator and an audio voltmeter available which you can substitute as

a

signal source and a level indicator. The signal generator can be connected directly to the ANT jack and the audio voltmeter across the SPKR terminals (to provide a

load).

)

Tune the Transceiver to the strongest signal in the

(

vicinity of 29 400 kHz. NOTE: The counter provides

many signals across the band, but the strongest

-

will be heard at (or near) the

Refer to Figure 1-9 and adjust the three trimmers for

(

)

.-..

~.~~~~

.~

~-

--

100

~

-....

kHz pants.

the 29.0 band to secure the greatest deflection of the

S-meter needle. Repeat the adjustment two or three times until no greater deflection can be seen.

signiis

.---

Figure 1-9 (fold-out from Page 240) identifies the trimmer capacitors to be adjusted for each band switch position.

INSERT THE LONGER INNER LEAD

THROUGH THE PLUG AND WRAP THE

SHIELD LEAD AROUND THE PLUG.

TIP

OF

APPLY HEAT TO THE PIN ONLY LONG ENOUGH FOR THE SOLDER TO BE DRAWN UP INTO THE PIN BY CAPILLARY ACTION

SOLDER THE SHIELD LEAD ONTO THE PLUG.

CUT OFF EXCESS WIRE

FROM THE TIP

Refer to Figure 1-10 and install a phono plug on the

( )

free end of the

24" shielded cable connected to circuit

OF

Figure

THC PIN.

1-10

THE

DLR

board A.

Insert the phono plug in the ANT jack on the rear

(

)

panel (below the heat sink).

(

I

Check that the rear panel antenna switch is in the

CIpJposition.

(

I

Set the front panel controls as follows:

.

)

Tune to the strongest signal near 29 000 kHz.

(

)

Adjust the Low End trimmer for maximum S-meter deflection and write down the reading in the margin opposite this step.

Turn the BAND

(

)

witch to 29.5 and tune to 29 700

kHz.

(

I

Adjust the High End trimmer for maximum S-meter deflection. Note the meter reading.

(

)

Compare the two S-meter readings and adjust the trimmers according to the following examples:

Examples:

1. If the meter reading at 29 700 kHz the 29 000 kHz reading, adjust the Low End trimmer to increase the meter reading.

If the meter reading at 29 000 kHz

2.

700

the 29

kHz reading, turn the BAND switch to 29.0 and tune the Transceiver to 29 000 kHz. Then adjust the High End trimmer to increase the meter reading.

(

)

Repeat the preceding adjustments two or three times

to secure the most uniform response.

(

)

Turn the BAND switch to 28.0 and tune the Transceiver for the strongest signal near 28 400 kHz.

is

lower than

is

lower than

RF Gain Fully clockwise A LC Depressed AGC Fast

)

Tune all three trimmers for this band for maximum

(

S-meter deflection. Repeat the adjustments for the highest S-meter reading.

Band 29.0

Level Fully counterclockwise

9

USB Depressed ON Depressed

Buttons not mentioned should be released.

I

( )

If not already done, install the extender board and circuit board G in position

G.

(

)

Tune the Transceiver for the strongest signal near 28 000 kHz.

( )

Adjust the Low End trimmer for maximum S-meter deflection and note the meter reading.

(

)

Turn the BAND switch to 28.5 and tune the Transceiver to the strongest signal near 29 000 kHz.

1

Adjust the High End trimmer for the greatest S-meter

(

deflection and note the meter reading.

(

)

Tune the Transceiver to the frequency having the lower meter reading, if necessary. If the 29 000 kHz frequency has the lower meter reading, adjust the Low End trimmer to increase the reading. If the 28 000 kHz frequency had the lower reading, turn the BAND switch to 28.0, tune to 28 000 kHz, and adjust the High End trimmer to increase the meter reading.

( )

Repeat the adjustments two or three times for the most uniform response across the band.

(

)

Follow the same procedure and adjust the bandpass filters for the 21.0, 14.0. 7.0, and 3.5 bands. The trimmers for each band are shown in Figure to Figure adjustments of each filter.

I I

'%.'?

21-215

~ii~i5'5

7-7'5

5.

28.0 5

28.

21.0

14.0

.

7.0

3.5

(

1

Tune the Transceiver to 3800 kHz. Then select th strongest signal within 5 kHz of this frequency.

(

)

Set the SMETER LEVEL ADJUST control (see

Figure

reading of

Remove the phono plug from the ANT socket on the

(

)

rear panel and unsolder and remove the shielded cable

and the 18 pF capacitor from the foil side of circuit

board A.

(

)

Remove the extender board and reinstall circuit board

G

1-1 1 for the three frequencies to use for the

FREQUENCIES

MID-BAND

I

RDJ.

TRIMMERS

in position G.

3

I

29400 29 000 29 700

28 400

21 100 14 200

100

7 3

800

1.3, fold.out from Page 237) S9+50.

LOW

Figure

END

28 000

21 000 14 000

7

000

3

500

1-1

1

HLGH

for

COUNTER CLOCK SETTING

NOTE: The counter clock output will be calibrated against the signal of station WWV, Colorado, on 15,000 kHz or station CHU, Canada, on 7.335 kHz. One

may be more easily received than the other in your location.

of the stations

1-9. Refer

END

29 000

21 400

'4400

7

300

4

000

an

)

Connect an antenna (suitable for the frequency of the

(

calibration station selected) to the COM antenna

socket. Be sure the rear panel switch

)

Turn the BAND switch to WWV or 7.0, as appropriate.

(

)

Depress the ON button.

(

Tune to zero beat station

15.000 kHz or station CHU at 7335.0 kHz.

(

)

Adjust the tuning so the voice announcements sound

natural.

(

I

Adjust the time right-hand corner of circuit board A (next to the crystal) until the display reads

POSSIBLE CAUSE CHART

1. Display cannot be adjusted to agree with

I

CHU frequencies.

A.

6.

(

)

Release the ON button.

LOW POWER TRANSMITTER CHECK

()

Check coil L321 on circuit board C (#85-1420.3) to be sure the coil slug the coil form (see Pictorial

-

i

'1

Plug in circuit board C. Visually check to make sure

(

the peaking coils do not touch the metal shield. If

necessary, bend them over enough to clear the shield.

)

Refer to Pictorial 12-38 (fold-out from Page 243) and mount right side panel. Plug the circuit board into connector

J

and secure

and GJ with 6-32

Plug the HI and LO shielded leadscomingfromchassis

(

\)

cutout BL into the corresponding sockets on the

driver circuit board.

(

,

Connect a dummy load (capable of dissipating

watts) to the ANT (antenna) socket on the rear panel.

( )

set

the BAND switch to 3.5.

Turn the LEVEL control fully wunterclockwise.

(

1

Turn the SIDE TONE and ANTI-VOX controls fully counterclockwise (rear panel view).

Depress the ON. PWR and TUNE buttons. All other

(

buttons should be released.

is

still

WWV

in the vicinity of

base

trimmer capacitor on the upper

15,000.0 or 7335.0.

YlOl not with~n tolerance. C114 defective.

is

still flush with the bottom of

5-1 2 on Page 89).

-

the

driver circuit board (#85-14211 on the

it

to the three mounting holes at GG. GH.

x

318" screws.

at COM.

WWV

or

100

CAUTION: Never change bands when the TUNE bunon depressed.

(

)

Advance the LEVEL control and check for power output

within the

meter should read about 1 on the 0 to 15 (relative power) scale.

(\)

Release the TUNE button.

(

i

Turn the BAND switch to the next higher frequency band, depress the TUNE button. and check for

in the middle of the band and at each band edge until all bands 3.5 through 21.0 have been checked.

POSSIBLE CAUSE

1.

No meter indication. A. B.

at

the middle of the band and about 25 kHz

uooer and lower band edoes. The

. .

~

~~~

~~

.

CHART

Wiring of the meter switches.

Refer to the

IF circuit boards in the "Maintenance" section.

ALCIoutput filter, driver or Trans.

-

an el

output

is

1

( )

Depress the TUNE b;tton.

(

9

Adjust coil L310 for a peak indication on the meter.

Release the TUNE bunon.

(

\

(

I

Turn the BAND witch to 29.0 and tune the Transceiver to 29 100.

Depress the TUNE bunon.

(

\

(j

)

~dj~a

(\I

Release the TUNE button.

(

)

Turn the BAND switch to 29.5 and tune the Transceiver to 29 600.

(' )

Depress the TUNE button.

(

'

)

Adjust colls L309 and L320 for a peak indication on the meter. Repeat the adjustment until no higher reading can be obtained.

coil

L31g

for

a peak indication on the meter.

i

1 I

I

d

'

Depress

step. The meter should show an ALC indication as

the

\

Release the ON button.

(

\)

Ten

Meter I FIPredriver

Make sure your dummy load is connected to the ANT

( ,)

socket.

NOTE: The coil not require turning the coil slugs more than 114 turn from the factory setting. Be sure to correctly identify each coil before inserting the alignment tool. Be sure the meter drops to 0 when the LEVEL control

--

Depress the ALC and ON bunons,

(

Refer to Figure 1-12 (fold-out from this page) for the

following steps.

(

.)

Turn the BAND switch to 28.0.

(

\I

Tune the Transceiver to 28.100.

NOTE: During the following

indication will vary with the setting

Keep the meter reading aEgri_"s connected.

the

ALC

MICICW-LEVEL control

Filters

adjustments in the following step should

is

~ ~

fully counterclockwise.

wiL

.

and

repeat

the

preceding

is

advanced.

.-

_

-

adjustments, the ALC NOTE: Make sure that a 100 watt dummy load is mnnected

of the LEVEL

. .

-

--

-1.

I\

)

Repeat the foregoing series of steps two or three times

until you are sure the maximum reading has been obtained.

(\

)

Release the TUNE and ON bunons.

POSSIBLE CAUSE CHART

1. No ALC-indication. A.

B. Refer to the driver circuit board in the

C.

.

2.

Response across one or more bands

A. Refer to the Transmitter IF circuit board in the

Display erratic on one or more bands.

3.

A.

,

CW

CHECK

to the ANT jack on the rear panel and that your speaker is

Wiring of the meter switch.

"Maintenance" section. Refer to the transmitter IF circuit board in the "Maintenance" section.

is

not uniform.

"Maintenance" section.

Readjust the VFO level as required.

I

-

Figure

1-12

PICTORIAL

12-39

PICTORIAL

12-41

1

Plug a key into the KEY jack on the rear panel. A positive keying voltage leads of any grid block keyer must be reversed.

(

1

Turn the LEVEL control fully counterclockwire.

(\I

Turn the SIDE TONE level control fully counterclockwise (rear panel view).

('

)

Depress the PWR, VOX, CW, and ON buttons. All other buttons should be

',

1

Tune to approximately

(

)

Close the key. The meter should read between 112 and 1 as the LEVEL control is advanced.

(

\)

Close the key and turn the SIDE TONE control clockwise (rear panel view) for a comfortable volume level.

(

7

Release the ON button.

POSSIBLE CAUSE

CHART

is

present at this jack, so the

released.

7000

kHz.

wmpound pods onto the mounting plate. Use your

finger to distribute a thick coating over the plate.

Keep the compound off the circuit board.

(

I

WASH YOUR HANDS.

11

/

(

,)

Graw the &es of the P.A. circuit board, edge toward the front panel, and push the six circuit

board connectors down onto connector H power transistor studs fit into the four holes in the heat sink. Then push the P.A. assembly back against the heat sink. Secure the assemblv with four 6-32

112"

screws at GR, GS, GT, and GU.

(

\

Push the phono plug on the P.A. cable into the PA

OUTPUT rocket on the circuit board.

CAUTION: Check to make wre that all five cables in the P.A. compartment are properly connected. If you make an

error at this point, you may have to replace the four power

vansistors.

(

1

Set front panel controls as follows. The position of other controls is immaterial:

tilt

so

lt~p

the four

x

1

No CW output or no side tone output. A.

Refer to the transmitter

board in the "Maintenance" section.

r

P.A.

(Power

CAUTION:

The thermal compound in the following steps can

injurious to both your eyes and your clothes.

handled with utmost care.

KEEP THE COMPOUND AWAY FROM YOUR EYES.

Wash

your hands immediately after using the compound. Should you get any in your eyes, wash them out with water at

once and get to a doctor as scan as possible.

KEEP THE COMPOUND OFF YOUR CLOTHES.

the

wmpound on your clothes

white stain.

Y

Refer to Pictorial 12-39 (fold-out from this page) for the

following steps.

Amplifier) CIRCUIT

audiolregulator circuit

BOARD

It

should be

If

you get

it

may leave a permanent

be

LEVEL: BAND:

VOX DELAY: Fully counterclockwise

(

)

Connect the socket.

(

1

Connect the cable from the power supply.

100

watt dummy load to the ANT

Fully counterclockwise

7.0

APPLV THERMAL

COMPOUWD

om

(

,)

Refer to Detail 12-39A and position the P.A. circuit

board (#851422) with the aluminum mounting plate up. Then squeeze the contents of two thermal

Detail

12-39A

[g&?*=---=*:-*d

Page 245

CAUTIONS:

Do not exceed

1.

2.

Whenever the Transceiver

power

and period (receive mode) of five times the TUNE time (for example, 10 seconds TUNE followed by 50 seconds carefully observed in the following steps. Complete duty cycle information section of this Manual on Page 261.

(

)

Depress the following buttons; all other buttons should be released: PWR, HI and ON.

( )

Depress the TUNE button..

( )

Advance the LEVEL control. The meter should read approximately 10 on the upper scale.

(

)

Depress the ALC button. The meter should approximately full scale.

(

1

Release the TUNE button.

)

Perform the preceding four steps at each position of

(

the BAND switch, being careful to observe the duty cycle. There should be no output at the

position.

30

seconds in HI power and TUNE.

is

o~erated in both HI

TUNE,

w/th TUNE button released). This must be

the

duty

cycle

requires

is

shown in the Operations

an

OFF

read

WWV

CARRIER SUPPRESSlON

)

Connect the 50

(

( )

Connect the microphone.

)

Depress the PWR, USB. HI and ON buttons. Other

(

buttons may be released.

(

)

Turn the BAND switch to

NOTES:

Key the transmitter (use the microphone PTT switch)

1.

for several short periods while making the following adjustment. Prolonged keying of the Transceiver while attempting to achieve an optimum setting creates an undesirable heat rise which could damage the output transistors.

2.

Look down into compartment E along the right side of the circuit board and identify control trimmer capacitor controls in Figure may be necessary to bend the two disc capacitors apart to gain access

(

.

Turn the MICICW LEVEL fully counterclockwise.

( )

Key the transmitter for short periods and alternately adjust (minimum meter deflection). The meter indication should be at, or near, zero.

R666 and C648 for the best possible null

.Q

dummy load to the ANT socket

7.0.

C648. (See Carrier Suppression

1-3. fold-out from Page 237).

to the screwdriver slot of C648.

R666 and

It

POSSIBLE CAUSE CHART

1.

No output or low output. A. P.A. transistors. Measure voltages

under P.A. on Page 269. Transformers incorrectly wired or shorted. Use

0.

an ohmmeter to check for a short circuit from connector pins 5 and 6 to chassis.

Leads of L813 on

C.

wired. Gray wire through LB13 shorted.

D. E. Chassis wiring (particularly

-

2. No input from driver. A. Check at connector pin

(

)

Release

all

buttons,

as

shown

ALCIFilter board incorrectly

RG-58AIU).

3

with RF probe.

(

)

Depress the LSB button. If the meter indication

higher, make the best possible compromise adjustment

between USB and LSB.

NOTE: If you have a general coverage receiver, tune

carrier frequency and use its S-meter as a sensitive indication

of maximum carrier suppression.

3.395

( )

TRAP ADJUSTMENT

Remove circuit board D.

Preset these controls:

.

BAND: 3.5

LEVEL: Fully counterclockwise

is

it

to the

any

Page

246

(

)

Depress buttonsPWR, HI, alld

(

1

Depress the TUNE button.

(

1

Turn the MICICW

(

I

Carefully observe whether the meter needle moves up-scale.

(

1

If there

the right side of circuit board C (Figure

null (least indication). Adjust

direction. output to

is

LEVEL

any meter indication, adjust coil

ON.

fully ,lockwise.

it

in a counterclockwise

L321

1-12)

on

for a

(

( ) (

(

rc43&=**-+*:+*wJ

)

Depress the there complete. If there is a meter indication, switch back and forth between the best possible null at both positions.

Release the

)

Reinstall circuit board D.

)

Check the power output at less than you previously secured, turn the slug of coil

L321

LSB

button and key the Transceiver. If

is

no meter indication, the adjustment

USB

and

LSB

and adjust

ON

button.

3500

kHz. If theoutput

clockwise just enough to return the power

normal.

L321

is

for

is

NOTE:

except

attaching upward

the

Refer

I

rubber

)

to

If

that

tilt

you

install

cabinet

PICTORIAL

The

top

four

the feet.

of

the

feet

at

Pictorial

wish

a

rubhr

shell.

BOTTOM

and

bottom

holes

are

If

you

panel,

the

hyo

12-40

for the

to

have

foot

Use

6-32

12-40

cabinet shells

provided

wish

use both

front

the

at

x

in

the

your

Transceiver

the

Corners

Transceiver cabinet

each

corner

112"

hardware.

are

bottom shell

tapered

of

the

bottom

steps.

of

the

$

#.

LOCKWkStIER

6-32

1

identical

to

have

spacers

shell.

sit

twel,

bottom

NUT

for

an

and

Refer

)

Attach

(

a

holes

and

( )

Place

cabinet edge flat

in

( )

Similarly, with its flat

to

Pictorial

10-32

GP

washers.

the

washers.

12-41

a

cabinet retainer strip

x

112

GC

and

on

the leh

the

chassis

between

The

half-circle cutouts in

place

lower

Turn

for

screw

GK

on

in

bodies

the

edges

the

two

the

right

panel.

Leave

the

cabinet

the

of

top

cabinet shell on

between

the

bard pullers

four steps.

to

each

3M"

side

the

bottom

retainer

the

10-32

the

cabinet

the

retainer

side panel.

OD

flat washers

panel

screws

shel

strip

screws

edge.

down.

and

loose.

and

strip

holes

1

with

the

must

the

Use

GM

the

314"

rest

chassis

and

the

REW

at

,

(

)

If

you

wish

the

front panel rubber hardware. Install a tapered each

foot

on

front corner

each

with

rear

6-32

tilted

upward, install

corner with

spacer

and

a

x

1-1

12"

hardware.

6-32

rubber

x

foot

112''

at

a

(

)

Tighten

This

completes

the

"installation"

the

four

the

assembly of

section.

10-32

scrms.

your Transceiver.

Proceed

to.

Page

248

rEFG=-*-w***:-si

3

Figure

2-1

POWER SUPPLY HP-1144

,,o,s.*".c

+SEE 58-614 MANUAL FOR

TRAPEZOID CONNECTIONS

z*v.~.s

Figure

2-2

8"

PLTC*

OUT

A""

."OlO

se"R

2

STATION CONSOLE SB~634 4n SPEAKER

SB-604

TO ANTENNA

INSTALLATION

The Transceiver should be placed where adequate air

I'

circulation is present in the area of the heat sink, as there is

appreciable heat generated by the final transistors.

I'

FIXED STATION INSTALLATION

Figure

2-1

shows basic fixed station connections. Figure (fold-out from Page 248) shows connections for various accessories that may be used with the Transceiver. Figure

2-3

(fold-out from Page 251) show the basic station

connected to a linear amplifier. Cables (not furnished) can

be

prepared following the instructions in Figure

the cables to the

lenaths reauired for your installation.

24.

2-2

Make

PREPARE

k~''7

EACH

END

AS

SHOWN

GROUNDING

A

good earth or water pipe ground should be connected to the ground post on the rear apron of the Transceiver. Use the heaviest and shortest connection possible.

Before using a water pip ground. inspect the connections

around your water meter and make sure that no plastic or

rubber hose connections are used which interrupt electrical continuity to the water supply line. any insulating water connectors found. Use heavy copper wire and pipe clamps. one point at the operating position and then ground this point as discussed above.

It

is best to ground all equipment to

ACCESSORY PLUG VFO

The Transceiver must have a jumper wire connected between pins

2

and 5 on the accessory plug. A cap

this plug. accessory VFO.

Install a jumper around

is

furnished for

IN

AND

A

shielded jumper wire must be connected between the

VFO IN and VFO OUT jacks unless you are using the

CUT

OFF EXCESS WIRE

FROM THE

TIP

Figure

OF THE

2-4

OUT SOCKETS

PIN.

SOLDER

Page

250

KEY CONNECTIONS

-L**-*-*

*=**B

In the CW mode, a positive voltage is present at the

KEY

socket on the rear panel. If you use a key designed for grid

Mock keying, the usual keyer leads should be reversed so the keyer output lead is connected to the shell of the phono plug and the keyer common, or ground, lead

is

connected to

the pin of the phono plug. If your keyer uses a relay, the lead connections are usually immaterial, although its

schematic diagram should be studied to

insure proper

connections.

LINEAR AMPLIFIER CONSIDERATIONS

Heath Amplifiers

Figure 2-3 Heath amplifier.

shows

the installation of the Transceiver with a

ALC Connections

If your amplifier has ALC (automatic level control) output provisions, connect a cable between the ALC jack on the Transceiver and the linear amplifier. The ALC bias voltage from the amplifier helps prevent transmitter overloading and "splatter." Although protective circuitry of this nature valuable circuit element,

it

is not a substitute for proper

is

adjustment of the exciter and its drive level to theamplifier.

Antenna Relay Connections

Many amplifiers have an internal transmit-receive relay which is

Heath amplifiers are of this type. This Transceiver has relay contacts available to operate the transmit-receive relay. The grounding connection may be made by a shielded cable (or other 2-conductor wire) connected to the accessory socket.

pins

for the relay coil.

actuated when the relay coil circuit is grounded.

8

and

9.

Use pin 9 for the ground connection and pin

1.

REMOVE INSULATION.

REMOVE ALL BUT

2.

THE BRAIDED SHIELD.

3.

UNBRAID THE SHIELD AND TWIST THE

FINE SHIELD WIRES FORM A STRANDED LEAD.

1-118"

OF OUTER

114"

OF

114"

OF

10

a

SHIELD

5.

SLIP THE HOUSING AND SPRING ON THE CABLE.

6.

BEND THE BARE END OF THE GROUND LEAD AND THE

SHIELD BACK OVER THE SPRING AND SOLDER.

SOLDER SWITCH

8

7.

PUSH THE AUDIO LEAD THROUGH PIN I AND THE SWITCH

LEAD THROUGH PIN NUMBER INSIDE

8.

SOLDER BOTH PINS ON THE END, THEN CUT OFf THE

(SHIELD) LEAD

2

OF

THE CONNECTOR BASE (NOTE

CONNECTOR BASEI.

AUDIO SWITCH

OFF

CUT

9.

SLIP THE HOUSING OVER THE CONNECTOR BASE AND

FASTEN

WlTH THE OTHER SETSCREW.

WlTH A SETSCREW. FASTEN THE SPRING

Fiwre

EXCESS

2-5

MICROPHONE CONNECTIONS

A high-impedance microphone equipped with a push-tetalk witch should be used with the Transceiver or VOX methods may be used to turn on the Transmitter. two-pin microphone connector (Amphenol 80MC2M) is furnished for this purpose. It should microphonecable as directed in the following steps.

so

either the PTT

A

he connected to the

Page

251

Heath

(

Microphones

1

Determine the desired length of your microphone

cable, and cut off any excess.

)

Perform the numbered steps in Figure

2-5.

Other Microphones

If you use a microphone different than the one shown, connect the lead from the microphone element to pin 1 of

the panel connector. If the microphone has a

connect this lead to pin

ground side of the circuit, should be soldered to the spring

as shown in Figure

2-5.

2.

Shield wires, to complete the

PTT

switch,

Other Power Supplies

Should you use other than the one available from the Heath Company, follow the principles shown in F~gure the Heath power supply cable

a

power supply for fixed station installation

2-6

which shows how

is

connected.

LUG

9

..........................

LUGS

11.1.

2.3.4-----13.8

5.6---------P0WER SUPPLY

LUGS

~.~.~.I~------NEGATI~E

This completks the "Fixed Station" installation instructions.

If you are going to also use your Transceiver as a mobile

station, proceed

below. If you

the "Operations" section.

tothe "MobileStation lnstallation"section

do

not plan a mobile installation, proceed to

voc

CONTROL

CHASSIS

Figure

TO

2-6

i

MOBILE STATION INSTALLATION

This section of the Manual will discuss Transceiver in an automobile, but the same principles apply to installations in other types of conveyances, such as a boat or airplane.

A Mobile Mount is available for and is recommended for Mobile operation. With this mount, the Transceiver can be quickly and easily installed or

removed so operation.

'1

Make sure the voltage output of your battery charging system is under any circumstances. If the voltage is not within these

Y

it

can be used for mobile and fixed station

at

least 12.6 volts and does not exceed 16 volts

the

installation of the

use

with the Transceiver.

limits, have the system adjusted. See the discussion in the "Operation" section of this Manual.

CAUTION: Never reverse the polarity of the input voltage, as the transistors will be permanently damaged. recommended that each of the wires from the battery to the Transceiver be permanently tagged or otherwise marked as to polarity at the battery end, to transistor damage if the wires

I

If the frequency display should fail to light when the Transceiver is turned on, turn proper polarity of the power cable.

minimize the possiblity of

should ever be disconnected.

it

off quickly and check for

"Power Supply"

It

is strongly

B

@

POWER SUPPLY

HP

1144

3

-

@

U

@

n

I

Figure

2-3

MAY BE SHIELDED

FOR MORE COMPLETE

SUPPRESSlON

n

r

I\

SPARK PLUG WIRE OR

USE RESISTANCE WIRE

-

I I

T-E

VOLTAGE RFGULITOR SHOmN

BATTERY. A.TEINLIOR Ah0 IIEGGGLTOR COhhLCTI3hSM6"

IN

ORDER hDICITED. DO NOT BYPASS FIELD HINO hG

I

A RESISTOR

-

CAUTION

IN

SERIES. CHECK TERMINAL LOCATlON CIIIEFL..".

INDICATOR

-

IS

0h~Y

IICPREIEhTAT

V8

VE.

h01

ImOJT

RESISTOR

SPARK PLUG

Y

BE

VALUE OF

SUPPRESSOR

101 OWM

IK OHM

S uF

FEEDTHROUGH

.I

PF

FEEDTHROUGH

.SuF

I

YF

P

MANUFACTURER AND

REPRESENTATIVE TYPE ERIE TYPE L7VR-TOME ERIE TYPE L7VR-SUE

48P18 I40 AMP1

BRACKET MOUNT

SPRAGUE BULKHEAD MOUNT

IPRAGUE

MALLORY MALLORY AG-451

BOP3 120 AMPI.

48P9 iP 0 AMP1

BRACKET MOUNT

AG-451

BATTERY

Figure

LIGHTS

NOTE' ALL GROUND CONNCCTIONS SHOULD BE MADE TO THE COMPONENT

FERABLY BY MOUNTING SUPPRESSOR DIRECTLY ON THE COMPONENT

EEING BYPASSED. PRE-

2-9

.

-

?

T

THE

-

'.*F

ACCESSORIES

-,!

*

1

"F

T

-

RELAY

CONTROL

Figure

2-7

TO

Mobile antennas present loading situations which must be

carefully handled for each band. Because whip antennas

must be kept short for mobile use, they represent only a fraction of a wavelength on the lower frequency bands. Thus, their radiation resistance is extremely low and their

reactance is capacitive. Therefore, loading coils must and the losses kept low to insure a minimum pwver in the form of heat in the loa resistances.

god quality antenna will have low resistance losses, and

A with a

could for AM reception. A typical loading coil with a would have a bandwidth of 13 kHz to the half-power points at

Because of this sharp tuning, deviation from the center

frequency of the antenna will quickly introduce enough

reactance to present an

transmitter. The antenna should be carefully adjusted for a low

The following is a list of antenna considerations for each band of the Transceiver.

hi*

"(1"

loading coil, its bandwidth on 75 meters

be

less than the IF bandwidth of many receivers used

3.9

MHz.

impossible loading situation to the

SWR

before placing the transmitter in operation.

loa of radiated

"0"

be used

of 300

LUGS

11, 1.

BATTERY

DC

RELAY WITH RATING ISTARTER RELAY1

If

you are not using the Heath mobile mount, refer to Figure

2-7

for a typical mobile installation, and to Figure 2-8 for a

wiring diagram.

MOBILE

Mount the antenna according to the manufacturer's instructions. Be sure to make a good ground between the shield of the coaxial cable and the car body at the antenna base.

ANTENNAS

/

25-30

AMP CONTACT

Figure

2-8

112

A FUSE

LUGS

5&6

IN 58-104

PWR SOCKET

(ON-OFF

SWITCH1

conneftion

3.5-4

MHz

This band presents the greatest problem. The normal tuning range of a good antenna on this band is about 10 kHz on each side of the antenna's

Actual

these frequencies is 15 to 20 ohms; this represents an of nearly 3 to 1. In order to get proper matching to the 50

ohm line, a 1000

between the inner conductor and shield of the coaxial line at

the base of the antenna. Some antennas may require a

different value, somewhere between 300 and 1500

The antenna tuning must be checked after the capacitor is

installed. This capacitor is part of an to get a 50 ohm match. The inductive portion of this network is formed by

7-7.3

This band ordinarily does not need a correcting network, and has a useful bandwidth of about 50 kHz.

14

No network

measured resistance at me bas of an antenna at

MHz

80

VA

resonanr frequency.

pF mica capacitor should be connected

L

network that is used

a

portion of the loading coil.

&

LA..

a

2

.s;

:;

needed.

Bandwidth is approximately 100 kHz.

SWR

pF.

Page

253

No netwwk needed. Bahidth is about

band

The antenna fw this with no kHz.

A

A whip antenna that is properly tuned on have a high peak of receiver activity for about around the antenna's resonant frequency. Turn on the receiver and tune through the band to find the peak of receiver activity for the Then adjust the length of the whip in and retune the receiver until the peak of receiver activity is centered around the frequency at which you normally operate. The antenna can then be tuned as described in the following steps. The receiver peaking may not be noticeable

on

(

load~ng coil required. The bandwidth

Typical

bands other than

I

1

Tuning

1.

Connect an SWR meter in series with the lead to your antenna.

2.

Set the SWR meter

is normally cut of

Procedure

present setting of your antenna.

75

meters.

to

the "forward" position.

150

kHz.

114

wavelength,

is

about

75

meters will

114

inch increments

25

200

kHz

B. If the point of lowest

desired operating frequency, lengthen the antenna

as

described below.

C. Change the antenna length in

and repeat steps

until the minimum should be about frequency. NOTE:

capacitor at the

previously, if you cannot get the about

1.2.

2,

base

SWR is higher than the

114''

increments

3,

and 4 at each new length

SWR is obtained. The SWR

1.2

or less at the desired

It

may be necessary to add a

of the antenna, as described

SWR down to

NOISE SUPPRESSION

To obtain good noise suppression, you must suppress electrical interference at its source so

input of the receiver. Once

be

suppressed by bypassing, etc.

Although all automobile ignition systems are similar, there are numerous of manufacture, etc. We are therefore unable to offer specific advise on how to eliminate noise and interference originating from these systems. However, generally accepted

noise suppression techniques are included here as a guide. The Heath Company cannot accept responsibility for any damage resulting from the use of this information.

differences- depending on make, model, year

it

has been radiated, noise cannot

it

does not reach the

CAUTION: To avoid damage to the power transistors during the antenna tuning procedure, be sure to observe the duty cycle restrictions described in the "Operations" section of

this Manual. Better, use

adequate meter deflection.

(

)

3.

Depress the HI and TUNE buttons and adjust the LEVEL control for a full-scale meter indication on

the SWR bridge.

4.

(

Switch the SWR meter to the "reverse" position. Note the SWR reading.

1

5.

Switch the SWR meter to the "forward" position. Then set the transmitter to higher and lower frequencies, and repeat steps frequency, until you find the minimum SWR.

)

6.

Set

the transmitter to the desired operating

frequency. Then adjust the length of the antenna as

follows:

A. If the point of the lowest desired operating frequency, shorten the antenna as

described below.

low power output if you can obtain

5

and 6 at each

SWR is lower than the

It

is difficult to determine the source of various noise, particularly when several items are contributing to the noise. Follow the procedure outlined below to isolate and identify the various items that may be producing the major

noise interference.

In most cases, one source of interference will mask others.

Consequently,

item first, and then continue with the other steps. Figure 2-9 (fold-out from Page and the suggested placement of noise suppression components.

1.

Position the vehicle in an area that is free from other man-made electrical interference such as power lines. manufacturing processes, and particularly other automobiles.

2.

With the Transceiver medium speed. Then let up on the gas, turn the

ignition switch off and to the allow the vehicle to coast in possible on cars with automatic transmissions or power steering. If all noise stops, the major source of

interference is from the ignition system.

it

will be necessary to suppress the strongest

2521

shows a typical ignition system

on,

run the automobile at

accessory position, and

neutral. This may not be

types

of

Page 254

3.

If the noise has a "whine" characteristie and changes

in pitch with varying engine speed and is still present with the ignition off, then the generator is the major source of interference.

4.

A

distinct is sometimes called, that disappears with the engine idling, indicates the voltage regulator

5.

A

steady

ignition off indicates wheel or tire static interference.

This is more pronounced on smooth

6.

The same irregular when on bumpy roads, particularly at slow speeds, indicates body static.

but

irregular clicking noise, or "hash" as

is

at fault.

popping noise that continues with the

roads

type

of interference

as

in step 5, but more

Noise Suppression Troubleshooting Chart

Refer to the Troubleshooting Chart and Figure from Page noise interference. Naturally, not all vehicles will require suppression to the extent shown in Figure stubborn cases may require all the suppression components

it

shown, plus shielding of the ignition system.

252), to help determine how to suppress most

2-9,

Grounding

A

good ground to the automobile body

Recognize that a layer of paint between adjoining parts and

panels may cause

jumper between the parts may be required.

It may be necessary to bond various parts and body panels

of the automobile to each other, starting from the hood and

continuing to the trunk. This may include bonding of the

transmission line every few feet.

a

discontinuity

in the ground path. A

2-9

(fold-out

but some

is

essential.

TYPE

OF NOISE

Loud popping increasing to buzz with increased engine speed.

Whine

-

varies with

engine speed.

POSSIBLE

Ignition system.

Alternator or

generator.

CAUSE

RECOMMENDED

1.

Replace plugs with resistor type (recommended). Loose crimped connections should be clean-

2. ed and soldered.

3.

Place resistors in distributor system.

1.

0.1

!.IF coaxial type capacitor in series

with the armature (A lead).

2. Clean commutator.

3.

Replace brushes.

4.

Ground generator shaft

5. Parallel trap

capacitor) in tuned to

REMEDY

(#lo

w~re-coil and suitable

serles with armature A lead,

operating

frequency.

[~b-*--*=*-*%il

Page 255

TYPE

Distinct but irregular

clicking noise.

Same as above.

Loud popping noise that

changes from one type

road to another. Most pronounced on concrete.

OF

NOISE

POSSIBLE CAUSE

Voltage regulator.

Energy transfer to

primary system.

Wheel static.

RECOMMENDED REMEDY

0.1

1.

2.

1.

pF coaxial type capacitor in series with

the battery

A

series combination of a

capacitor and a

ground from the field components should be mounted as shown in the diagram, close to the voltage regulator.

Bypass at the following points: coaxial bypass in lead to coil from ignition witch (0.1 to gas gauge signal witch (0.5

(.5

pF); accessory wiring from engine com-

partment

Installation of front wheel static collectors

(available from most automotive distributors). These should be checked every 5000 miles for excessive wear.

(B)

and armature (A) leads.

,002

pF mica

4

a

carbon resistor to

(F) terminal. All

pF). Battery lead to ammeter (.5 pF):

(0.5

pF); to oil

pF); head and tail light leads

(.5 pF).

Same as above.

Irregular popping noise when on bumpy roads. particularly at slow speeds.

If an extensive amount of suppression is required, the engine

should

be

retimed and tuned up at a reputablegarage.

Tire static.

Body static.

1.

Injection of anti-static powder into tire

through valve stem.

1. Tighten all loose screws. Use heavy flexible braid and bond the en-

2.

gine to the frame and fire wall. Bond the control rods, speedometer cable, exhaust pipes, etc., to the frame.

b

Controls the volume

METER

Acts

voltage.

of

the

ar

S

meter.

ALC voltage.

Reads

DC input

and

relatwe

VOX

I

Cootrolr

receiver gain. Rowides

GAIN

Controls len$lfivity

mntrol

circuit.

of

the

volce

IDENTIFICATION

the station call letters.

I

a

mean*

of

CW

rnc

dbrplayw

MICROPHONE AND PUSH TALK CONNECTOR

PTT

PHONES PLUG JACK

For

low

tmpedanoe headphones lnd#cat#on

TO

-

Depres~

for

Deprerr

Depress ~ndlcatlon

for

Deprerr

Depress to blank out rtght hand dlgtt

Deprerr

relative

ALC

for

lnput

~nstalledi

of

wwer

and

S

for

noare

the dtrplay

for

VDX

mdlca

meter

voltage

blanker

operatlo"

ilf

I

?r-

MAIN TUNING

Figure

3-

I

VOX DELAY

Controls hold-," transmitreceive relay in VOX

CW

modes.

I

ATION

means

of

all

I

displaying

letters.

I

tlme

of

or

I

Displays rhe tranrceive frequency

VOX

DELAY

MODE

USB LSB

CW

SL

,

21

0

AGC BAND

MICICW

TUNE

HI

ON

88-104

\\\

-LEVEL

J

Selects fast

or

turns

Selects

station

MICICW LEVEL

Controls

10

both

or

AGC off

amateur

WWV

the

gain

SSB

and

slow

band to

at

15

of the trsnrmltter

CW moder

AGC

MHz

be

usedoor

Irecelve

anton

\

\IN TUNING

igure

-

3-1

Deperr for

Depreu for mode

Deperr mode Depess

CW

mode Deprerr

lower

rtdeband

-

lor

upper

rldeband

.

I

*anice,ve,

Deperr for

for

low power

for

to

apply power to

high

power

tune mode

Release

OPERATION

NOTE: YOU MUST HAVE AN AMATEUR RADIO OPERATOR AND A STATION LICENSE BEFORE PLACING THE TRANSMITTER SECTION OF THE TRANSCEIVER ON THE AIR INFORMATION ABOUT

LICENSING AND AMATEUR FREQUENCY ALLOCATIONS IS AVAILABLE FROM PUBLICATIONS OF THE FEDERAL COMMUNICATIONS COMMISSION OR THE AMERICAN RADIO RELAY LEAGUE.

Operation of the Transceiver has been simplified as much as possible to permit rapid adjustment by the operator. Once the initial settings have been made, necessary to readjust most of the controls. Read the following information carefully. Good operating techniques will provide good clean signals and long trouble-free life of the Transceiver.

it

should not be

CONTROL FUNCTIONS

Refer to Figure panel view of the Transceiver and a concise explanation of control functions.

Figure controls and connections. Figure

237)

circuit boards and subassemblies, as well as some additional controls. The following paragraphs describe the control

functions more completely.

3-2

is

a top view of the Transceiver chassis which identifies

3-1

(fold-out from Page

256)

for a front

263)

shows rear panel

1-3

(fold-out from Page

IMPORTANT: A transmitter which employs solid-state devices requires different operating techniques than one with vacuum tubes. For example, duty cycle restrictions must be strictly observed because power transistors are as forgiving as tubes. If the operating parameters of solid-state devices are not exceeded, they will last indefinitely, but they can be easily destroyed by carelessness. As a result, operating instructions are read, comprehended, and observed. They are not complicated, and will become second nature after you go through them a few times.

A number of the actions listed in this section earlier in this Manual, but are repeated here because they are essential for proper operation of your Transceiver.

it

is

extremely

important

were

not

that these

covered

DISPLAY

Displays the frequency to which the Transceiver is tuned, plus or minus want to blank out the right-hand digit, which displays the

100

Hz

frequency operation, the display will follow both the receiving and transmitting frequencies.

100

Hz. Depress the

points. If the accessory VFO is being used for split

"100

Hz" button if you

AF GAIN

'

IDENTIFICATION

The station call leners can be displayed here or the space can

be

blanked

out.

Increases the volume of the received signal with clofkwise rotation.

Page

258

RF GAlN

Clockwise rotation increases the receiver sensitivity. This

control is usually positioned fully clockwise. Turn the

control counterclockwise to reduce sensitivity when exceptionally strong signals are being received, or to reduce

adjacent channel interference.

VOX

GAlN

Adjusts the input level at which the voice-controlled relay circuits will operate. At

input will silence the receiver circuitsand place the transmit

circuits in operation.

VOX

The voicecontrol circuits.

VOX

Controls the length of time the voicecontrol circuits will hold the Transceiver in the transmit mode after the input has ceased.

button

DELAY

must

y

TEE

NB

.

this

level, either microphoneor

be depressed to activate the depressed.

CW

AGC

Selects fast or slow decay time for the automatic gain control, or turns the AGC circuits off.

BAND

Selects the desired amateur band, or station WWV (National Bureau of Standards) at the panel extends for receiving only.

is

the low frequency end of each range, which

500

kHz

15

MHz.

The frequency printed on

upward in frequency. The WWV band

MIC

S-METER

Figure

53

METER WITCH

is

The meter face

following indications with the designated switch button

13.8:

ALC:

@e

PWR: lnd~cates relat~ve power output on the upper

shown in Figure

Power supply voltage (upper scale).

1.

Receiving, meter gives an S-meter indication

on the lower scale from

2.

Transmitting, Al C action should

6

on the upper scale.

?-pl

scale.

24!124g

3-3.

The meter gives the

0

to S-9

+

60

--

VOX

When this button is released, the must be pushed to transmit.

When this button activated. The position of the USB, LSB, and CW buttons

is

will determine whether the microphone or the key will cause transmission to occur.

is

depressed, the voice-control circuits are

PTT

microphone switch

dB.

not exceed

Connect a high-impedance microphone, preferably with a

PTT

(push-totalk) witch. The microphone cable Gonnector

is furnished.

PHONES

Connect low impedance headphones through a phones plug. When the plug is inserted in this jack, the loudspeaker is automatically disconnected.

MlClCW LEVEL

When the USE or LSB buttons an, depresred, this control

adjusts the audio drive. When the CW or TUNE buttons are

depressed, this control adjusts the carrier

level.

When this button is depressed, the right-hand digit of the frequency display is turned off.

j-u

coclrc,,c,

CUOiybGb

NB

CE~VE~

D'\S+7

If the accessory noise blanker has been installed,

activated when you depress this button.

,r

flI(FII5

RF

L~;FI

3

3N

'kr

F~L

AVV

SL.,GHT

0bJ'ilc

6otJE.

bAkJb,TUR+

c~rnff~o~

CL*I

b'.%lqaT.hqw

TNE

agrii

me

i~

tQkLII-

it

is

USB, LSB, CW

Depress the appropriate bunon for upper sideband, lowel

sideband, or

CW

transmission.

(&%J=**--=*:**al

Page

259

-

TUNE

Depress this button to secure a carrier for tune-up.

Depress this button for high power output. Release the

button for low power output.

ON

Depress this bunon to turn the Transceiver ON. To turn the Transceiver OFF, push the button again and quickly remove your finger. This will release the button.

ANTI-VOX CONTROL

Turn this control clockwise to adjun the VOX circuit so a received signal from the speaker will not feed back into the microphone and cause unwanted transmission.

(Rear

Panel)

SIDETONE CONTROL (Rear Panel)

SMETER LEVEL CONTROL

Controls S-meter sensitivity. Instructions for setting this control will be found in the "Test and Adjustment" section under "Preselector Filter Coil Alignment" (Page 242).

CARRIER SUPPRESSION CONTROLS

These controls on circuit board E balance out the carrier. See "Test and Adjustment" section under "Carrier Suppression" (Page 245).

TIME BASE CONTROL

Tune in station WWV until the announcer's voice sounds

natural. Release the

trimmer capacitor on circuit board A until the display is

15

000.0.

100

p?.

202

Hz button. Adjust the time base

VFO SHIFT

A trimmer capacitor in the VFO to be adjusted so the display remains constant in either USB or

LSB.

VFOFREQUENCY

-

.

1

I' !

1

:

E

Controls the loudness of the sidetone signal when you are transmitting CW (or in the TUNE mode).

A coil in the VFO which positions the VFO frequency range to properly

cwer the amateur bands.

TUNE-UP

NOTE: Once your Transceiver controls have been adjusted 2. for either your Transceiver on the air Other than to select your frequency, no other action is required.

Initial

Before attempting to use the Transceiver. check to make sure all of the following connections have been completed.

1.

SSB or CW operation, all that is necessary to place

is

to depress the ON button. installed in the ACC socket on the rear panel.

Actions

An antenna for the band in use should to the rear panel ANT socket. If a power amplifier is used, RG-58A/U coaxial cable should connect the ANT socket to the amplifier input. the PWR plug on the rear panel.

be

connected

be

used to 5. The power supply cable socket should be connected to

The ACC plug, with

install the plug of the Accessory

3.

The VFO jumper (or the Accessory VFO) should be

installed between the VFO IN and VFO OUT sockets

on the rear panel.

A

,,.

3.2 a to

SPKR socket on the rear panel, or headphones to the

front panel PHONES jack.

16

a

jumper between pins 2 and 5 (or

VFO), should be

speaker

should

be

connected

to

the

Page

260

6. The Transceiver should be connected to a good Preset the front panel controls as follows (CW means fully ground. clockwise.

CCW means fully counterclockwise):

l&%3=**-*-*:**%I]

If a power amplifier

7.

A.

The amplifier's ALC output should be connected to the ALC socket on the rear panel.

Providing the amplifier's transmit-receive relay

B.

the type which relay coil, the amplifier's relay coil connection should be connected to pin Pin

9

of the ACC socket must be grounded to

complete the circuit.

If an external receiver

8.

which must be grounded to allow the receiver to operate, this circuit can be connected to pin 10 of the

ACC socket. Pin

the mute circuit in the receive mode.

is

being used,

is

activated by grounding the

8

of the ACC socket.

is

used which has a mute circuit

9

must be grounded. This will ground

LEVEL RF GAlN

AF GAlN

BAND

VOX GAlN

is

VOX DELAY AGC METER VOX

1m

NB

MODE TUNE HI

ON

ANTI-VOX (rear panel) SIDETONE (rear panel)

'Viewed from the rear.

RECEIVING

Hz

-

MicICW

CCW

CW CCW

Any

CON CON Slow

13.8

Released Released Released USB or

Released

Released Released CCW* CCW'

LSB

The

receiver is broad banded and no preselector tuning

required. For best results, the antenna should be designed

for

a

50

SZ

impedance, or an antenna coupler should be used

to match the antenna's impedance to 50

1. Check the connections in "Initial Actions" (Page 259).

2. Connect the transmission line to the ANT socket on the rear panel.

3.

The rear panel slide switch should you are receiving and transmitting on the same antenna.

4.

Depress the ALC and the

5.

Depress the USB, LSB, or CW button.

Adjust

6.

the AF GAlN as desired.

ON

a.

be

buttons.

at COM when

is

7.

If you will use VOX operation, depress the VOX button and place the microphone in the position will occupy during normal operation, and tune in a strong station. The receiver will usually cycle on and off with the voice peaks the ANTI-VOX control clockwise (as viewed from the rear) until the cycling action ceases. Do not advance the control beyond this point.

8.

The AGC switch can be moved to another position, although most SSB operators prefer SLOW. operators may prefer FAST or OFF.

9.

Depress the NB button to activate the noise blanker, if'

one

is

installed.

If you use a separate receiving antenna, connect

10.

the REC socket on the rear panel and set the adjacent

slide switch at REC. Transmission will always use the antenna connected to the ANT socket.

of

the strong station. Turn

it

CW

it

to

cM=**-"*****dl

TRANSMITTING

Page

261

Transmitter

The power transistors used in the power amplifier stage of this Transceiver are not as forgiving of overloading and LOW power output position).

misadjustment as vacuum tubes. The principal source of difficulty is overheating. If you observe the duty cycle parameters carefully, the transistors will last a long time; if meaningful SWR meter indication of forward power.

you ignore or abuse these parameters, costly replacement will be required. Consequently, it carefully observe the duty cycle restrictions in the following table when using high power.

NEVER EXCEED 30 SECONDS TUNE BUTTONS DEPRESSED.

MODE

SSB

CW

TUNE

EXAMPLES:

1.

In CW, a one minute transmission should be followed by

1

ten-second tune-up requires

period. receiver only, adjust the coupler for greatest S-meter

2.

The on/off times transmit-receive cycles, but the maximum transmit

times must always be CW mode you should only transmit half the time (average) and should never exceed

continuous transmission.

Duty

Cycle

Restrictions

is

important that you

WITH BOTH THE HI AND

MAXIMUM

CONT~NUOUS

RECEtVE

TIME TIME TIME

2

units

1

unit

1

unit

a

one minute receive period. In TUNE and

1

unit

1

unit

5

units 30 seconds

a

50-second ~ff (receive)

can

be

averaged

observed. For instance, in the

TR~~M,T

over several

15

Th

1

hour

15

HI,

minutes of

2.

Connect Tranceiver as in "Initial Actions" (Page

3.

Depress the PWR, TUNE, and ON buttons (this

4.

Advance the LEVEL control until you

5.

Adjust the antenna coupler for minimum VSWR.

6.

Release the TUNE button.

7.

Turn the LEVEL control fully counterclockwise.

NOTE: Use the following high power

does not show an adequate reading when in low power. If

high power

high-power, TUNE duty cycle restriction.

Depress the HI and TUNE buttons. Then quickly

3o

,..,;%

repeat steps 4 through

,i

,;.

only enough to get useful VSWR readings.

A

53

%.

9.

Record the antenna coupler dial readings for the amateur bands of interest to facilitate future adjustments.

a

NOTE: If you are adjusting an antenna coupler with a

deflection.

is

used, carefully observe the 30 second,

7.

steponly if the meter

Advance the LEVEL control

SSB

1.

Check the connections in "Initial Actions" (Page

259).

is

the

get

259).

a

!

I

,

I

*

-7

9

ANTENNA

1.

b

COUPLER

If

you use an antenna coupler which has an WR meter, connect panel and your transmission line with

coaxial cable.

it

between the ANT socket on the rear

RG-58AlU

2.

Depress the ALC, USE (or LSB), and ON buttons.

3.

For PTT (push-to-talk), use the switch on the microphone to operate the transmit-receive relay.

4.

Set the BAND switch.

5.

For VOX operations:

a. Depress the VOX button.

Speak into the microphone and advance the

b.

VOX

GAlN until the relay pulls in reliably when

you speak. Advance the VOX DELAY clockwise until the

c.

relay holds in for the desired length of time after you cease talking.

6.

Speak into the microphone and advance the LEVEL control until the panel meter kicks up to volume with keying (or TUNE).

3

approximately CAUTION: Do not advance the LEVEL control beyond this point because it will not increase the power output. and the final stage may be overdriven.

which will result in clipping of voice peaks and

sideband "splatter."

(upper scale) on volce peaks.

3.

Leave the HI button released for low power operation. Depress the HI button for high power operation.

4.

Advance the LEVEL control only to the point where

the meter reading ceases to increase. CAUTION: A

higher drive level will not increase the power output, but a keying "thump" will develop.

Adjust the VOX GAlN control

5.

instantly when the key is depressed. Adjust the VOX DELAY control for the desired hold-in time.

6.

~djust the SIDETONE control (rear panel) for sound

7.

~f

desired, depress the

hi^

8,

completes

the

AMPLIFIER

If high power is desired. depress the

7.

8.

This completes the can proceed to transmit. No warm up time

CW

Transmission

Preset

1.

2.

the cmtrds

Depress the

PWR.

SSB

tuneup procedure and you advance the Transceiver's galn beyond the polnt where

as

in "Initial Actions"

VOX,

CW,

HI

button.

If you use this Transceiver with an amplifier

IS

required. ampl~f~er output ceases to Increase w~th rotatlon of the

LEVEL control

OTHER

(Page

259).

Thls

and ON buttons. and CW modes.

MODES

Transceiver

has been designed for use only In th~s SSB

cw

HI

bunon,

tune.up

sa

the relay pulls in

procedure.

.

DO NOT

TROUBLESHOOTING

CONTENTS

'3

Introduction.. Localizing the Trouble.

VFOIBuffer Troubleshooting Guide ,264

Receiver Troubleshooting Guide

Transmitter Troubleshooting Guide .268

Display Troubleshooting Guide Voltage and Continuity Checks ,274 Test Chart

Checking Transistors and Diodes ,274

.............

...

....................

INTRODUCTION

The table of "Contents" above shows the different types of information that are available in this section to help you.

Begin your troubleshooting by localizing the trouble to a specific area, as described below. Even if you are reasonably sure that you know the area your trouble that you read through "Locallzing the Trouble" because of the additional information that

it

Because Manual, you will often be referred to the "Maintenance" section (see Page 275) in the following pages. The "Maintenance" section has complete information on each circuit board, including a "Troubleshooting Chart," an "X-Ray View," a "Voltage Chart." a Schematic, and a "Circuit Description." You may also want to refer to the main Schematic for the entire Transceiver (fold-out from

Page 323) and to the "Chassis Photographs" (Page

is tied in very closely with this part of the

is

given there.

is

in, we

321).

suggest

263 264

........

......

.266

........

..........

,270

.273

..........

ASSISTANCE BY THE HEATH COMPANY

If you are unable to solve a difficulty, refer to the

"Customer Service'' information inside the rear cover of

Manual. Your Heathkit Warranty is inside the front cover.

If you know that the trouble you can save expense by sending only that circuit board for repair to either the Heath factory or to one of the Heath

Electronic Centers. See Circuit Board Service Policy on Page 281, which also contains the special Power Amplifier circuit board warranty.

REPLACEMENT PARTS

If you need a replacement part, whether or not warranty period, refer to the "Parts Lists" and to the "Customer Service" information inside the rear cover of this

Manual.

is

on a specific circuit board,

it

is within

this

.

I

i

1 I

i

1

I

ACCESSORIES SOCKET

See

the

mnnectmns

lnrtallatcon

Sectlon

for

Connect

wlth a heavy

to

your

wore

narx

RECEIVER

antenna

connect

hNT

it

here

530

ANTENNA

ConM

transcealna

your tranrmlnlnp

antenre

here

COM

ANTENNA SWITCH DRIVER OUT

DJM

Connect

rnlttlng

and

SEP

Use

antenna

7

or

for a reparate

SEP

a

mmmon

recelvlng

Inns

antenna

receovlng

WWER

Connen

wwer

A

PLUG

to cable

supply

(?

rocker

Output of tranrmlttw

on

1

Figure

-

OUT

3-2

10

~ry

Controir the ridetone signal

your

Ifstion ground Phone

wire.

loudnmr

when

CW

of

is being

the

patch

input

and

output

transmitter driver Positive keying volt=

verrp

Outpt

of

receiver IF.

the ludr

of

any

pasm

grid blo&

Re

Input

for

auxiliary audio

VFO inputlournut BPPBratUs. Requires jumper COnnRtion normal operation.

Connect

audio circuits

rourcn.

between

ALC

output

for

rockets

from

auxiliary

for

an

-----

ANTI TRIP

I---_-

S I DiTONE

OSC

ICW

ONLY)

MOD BUFFER

.

;

BfO

I

L-~LC-;

-----

I-----

FUNCTIONAL BLOCK DIAC

PREMIXER BPf

(F

T T

L--,

-----

'

SWITCH

I

----

;K

f

TIR

-----,-

4

CRYSTAL& TIR

I

-

FILTER

I

-----

DIAGRAM

I

VFO

I--

--

----

I

SWITCH MIXER FILTER

I

----

-----

I

1

I----,

BPF

2hD

RX

I

=

I

-

I I

8

6WHl

FUNCTION USED IN

BOTHTRANSMIT

AND RECEIVE

BAND PASSJILTER

-

I

- -

Y

-1

A

SEPARATE

RECANT

Page

264

LOCALIZING THE TROUBLE

a

Before you look for any other circuit malfunction, be sure you have the correct supply voltage. Do this by performing

the first six steps under "Chassis" on Page 233. 'Test Chart" on Page 273.

If your Transceiver was in operation for a time and

then a difficulty showed up,

you can also refer to the

Then localize your trouble to a particular area

circuit board for example) by using one or more of the

following methods:

Study the functional Block Diagram (fold-out from

264)

Page carefully. Then use deductive reasoning to pinpoint your trouble to a transmitter or receiver is operating, for example, look for your trouble in one of the circuits that is common to both of them, such as the VFO, the HFO, or a carrier generator.)

Check the wiring of the under-chassis terminals from the "Chassis Wiring Check List,"

300.

If

you h-mw your trouble is in the transmitter. or in

the receiver, or in the following sections:

"Receiver Troubleshooting Guide" "Transmitter Troubleshooting Guide'.'

"Display Troubleshooting Guide"

and the 'Theory of Operation" (Page 319)

~ecific area. (If neither the

foldaut from Page

the

readout circuits, refer to one of

. . .

(a single

.

Page

266

.

. .

Page

268

.

Page 270 the Transceiver on again.

After you localize

Refer to the correct part of the "Maintenance" section

(Page 275) to troubleshoot any of the circuit boards.

Very carefully check the front panel, rear panel, and chassis for any wiring errors or poor solder connections.

a

Read "Voltage and Cont~nuity Checks" (Page 2721 before you make any measurements. Also refer to "Checking Transistors and Diodes."

when

you

diminateboth

example, you should find a damaged resistor, be sure you find out what caused the resistor to become damaged

(wiring error, etc.). If the cause

replacement resistor may also be damaged when you turn

make

the

trouble to one area:

repain

cwseand

on

the

~~~~~~i~~~,

effmtof

is

not eliminated, the

the

be

trouble,

sure

~f,

to

for

i

!

1

i

1

VFO/BUFFER TROUBLESHOOTING GUIDE

LSB

SHl

FT ADJUSTMENT

If

the LSB shift adjustment cannot be made, check the voltage at the anode (unbanded end) of Dl201 on the VFO circuit board. When this diode the anode voltage will

LSB

pushbutton is depressed, and 0 VDC when the USB

CW

button is depressed. Instructions for access to the VFO

circuit board are included in the following section.

be

witch is working properly.

approximately 0.3 VDC when the

VFO OUTPUT VOLTAGE

This section is for use when there is no VFO output voltage, or the highest output voltage available is less than 0.35 VDC.

Use an RF voltmeter or an oscilloscope to make RF voltage checks. Be sure to use a high input impedance voltmeter megohms or higher) when you make DC voltage measurements at transistor leads to avoid erroneous readings caured by loading the circuit.

DC

or

(1

If you get the correct RF voltage reading at the input lead of a component but not at the output lead, the component is probably faulty and and the resistances measured

table at the end of this section) indicate variations of more

than

+20%, the resistors in the voltage path may have changed value, the supply voltage may be in error, or a transistor in the circuit could have an internal short circuit.

To check the components on the buffer circuit board, remove the VFO assembly from the chassis and remove the VFO shield two 4-wire connectors if they were disconnected during disassembly.

1

If

you are checking the VFO after

satisfactorily in the Transceiver, remove the VFO

plug from the VFO OUT socket on the rear panel VFO will not be loaded during voltage measurements.

so

should be replaced. If the DC voltages

at

each lead (as shown in the

the circuit board is accessible. Reconnect the

it

has operated

jumpey

so

the

1

J

/

rz****=*r-*d

To check the VFO circuit board, remove the mounting nut

from

L1201, slide the 4-pin connector up out of its slot, and remove the VFO bracket so the entire VFO assembly can be removed from the VFO chassis. Then reconnect the 4-pin connector to its mating connector power and the LSB shift voltage.

Make the RF voltage checks in the following steps. In the Test Point column, gate, and

expected at the transistor leads are given in the table at the

end of the steps.

S = source. The

B = base, C = collector, D = drain,

DC

( )

(

)

(

I

so

the VFO can receive

G

voltages and resistances to be

TEST RF POINT

-

VFO output

CofQl205 126 Check continuity to Output connection.

B

of Q1205

_

/--

VOLTS

-

0

0.1

----

(

)

Check for + 11 VDC at the appropriate leads of

R1226 on the buffer circuit board, and I31206 onthe

VFO circuit board.

NOTE: In the following table, if your voltage reading agrees with that in the RF Volts column. follow the instructions in the Action column. If the RF voltage reading varies in excess of 20% from the column and proceed to Ehe following step.

=

(

)

Turn oentrol RlZ32 on the buffer circuit clockwise.

Am

~roceadto f~llawlng step.

Check C1234 for a short circuit.

If

all

?::%

readings are correct, replace '21205.

OC

figurs, disregard the Action column

board

Voltage and resistance

Page 265

fully

(

I

eat Q1204 0.35 Check continuity to 01205.

(

\

6 of Q1204 0.8

(

S of Q1203 0.82 Check continuin/ to 01204.

(

I

GofQ1203 1.7 If all 01203 DC voltage and resistance

(

)

D of 01202 2.9 Check continuity to Q1203.

(

I

Sof 01202 1.7 If all 01202 DC voltages and resistance

(

Repeat the "VFO Output Adjustment" on Page 237.

Q1205 Collector

Base Emitter

Q1204 Collector

Base Emitter

It

all 01204 DC voltage and resistance

readings are correct. replace

readings are correct, replace 01 203.

readings are correct. replace

OHMS

RESISTANCE*

DC RF VOLTS VOLTS

--

0 1.25

9.2

9.8 .3

Q1204.

Q1202.

.1

Q1 203 Gate

Q1202 Gate

'Negative or common lead to chassis.

Source Drain

Page 266

RECEIVER TROUBLESHOOTING GUIDE

Refer to the "Receiver Block Diagram" 2671, which shows how signals flow through the receiver circuits, as you go through the tests on the following pages. Each circuit board is outlined with a dashed line, and the circuit functions are shown as solid blocks inside the 1. outlines.

Thjs

troubleshooting guide is divided tnto the following five

tests: "Audio Output," "Product Detector," "Preamplifier,"

"IF Amplifier and AGC," "Crystal Filter," and "Front

End." When you get the correct result for a test, proceed to the next one. If you do not get the correct result, the last step will direct you to the proper part of the "Maintenance" setion and will call your attention to some specific areas to check. When you turn to the "Maintenance" section:

1. Refer to any applicable parts of the "Troubleshooting Chart."

2.

Refer to the "Voltage Chart" and check the

voltages in your Transceiver at the areas

mentioned in the last step. (Also see "Voltage

and Continuity Checks," Page 272.)

3.

Check any questionable diodes and transistors.

See

Page 274.

4. Be sure each circuit is correctly wired and that the correct parts are installed.

5. Read the "Circuit Description" and Schematic to better understand and analyze your problem.

(fold-out from

smdy the

Page

For the following steps, you will need an input signal source

to Connect to the AUX AUDIO socket on the rear panel.

You can obtain this input in either of two ways:

(

1

(

1 If you do not hear any sound from your station

(

1

3.395

Use

a 1 kHz signal from an audio generator.

Connect a separate speaker to the free end of

2.

the 24" test cable (be sure to remove the 18 disc capacitor) prepared earlier for front end alignment. Then, to provide the signal, tap on the cone of the speaker or scratch fingernail.

Connect your input signal source to the AUX AUDIO socket on the rear panel. You should hear a sound from your station speaker.

speaker, proceed to "Receiver Board," Page 310. Check and the associated circuitry.

Disconnect the input signal source from the AUX AUDIO socket. If necessary, disconnect the speaker

from the test cable and reconnect the 18

MHz

TEST SIGNAL

0513 through Q518, IC502,

IFIAudio Circuit

P.

307

pF capacitor.

it

with a

pF

In order to check the remaining stages in the receiver section

yw will need a 3.395 MHz test signal. You can make this

AUDIO OUTPUT

(

Turn the power ON.

(

1

Turn the RF GAIN control fully clockwise.

( )

Turn the AF GAIN control to rnid.range. Page 306.

signal available as follows:

(

&f

)

Locate the 24" test cable Lift the end of 100

forms

a

junction with the ferr~te bead. To identify

R645, refer to the X-ray view on the fold-out from

S2

resistor R645 (on board

E),

that

cm-**-v"**c**d

Page 267

Connect a 1" R645 and pin 20 of board E.

(q

Unsolder the banded end of diode D603 and pull this lead

cut

Solder the free lead of the 18 pF capacitor on the test cable to the banded end of

(

)

Replace board E. A 3.395 MHz signal

at the phono plug on the

\

jumper wire between the free end of

(+

I

y

)

of the circuit board.

d~ode D603.

is

test

cable.

now available

PRODUCT DETECTOR AND PREAMPLIFIER

Insert the phono plug on the test cable into the IF

(

)

OUTPUT phono socket on the rear panel.

( )

Set the MODE switch to the LSB or USB position.

(

)

You should hear a tone from the speaker.

If you do not hear a tone, proceed to "Receiver

(

)

IFlAudio Circuit Board." Pase 310. Check T502, D506-D509, IC502 and associated circuitry.

(

)

Disconnect the phono plug from the IF OUTPUT

phono socket.

.

)

Again hold the test cable phono plug tip against pin

(

of circuit board speaker. check 0504 through

F.

If you do not hear a tonefrom the

all.

CRYSTAL FILTER

Inject a 3.395 MHz test signal at pin 1 on board E.

(

tone should

(

If you do not hear a tone, proceed to "Carrier GenlXtal Filter Circuit Board," Page 306. Check 0601, 0603, the SSB filter and the associated

circuitry.

be

heard from the speaker.

DISCONNECTING THE TEST CIRCUIT

( )

Disconnect the 18 pF capacitor from diode

(

)

Resolder the free lead of diode 0603 to its proper

hole in the circuit board.

(

)

Disconnect the jumper wire that is connected between

resistor

(

Reconnect and solder the free lead of resistor R645 to

the circuit board.

R645 and pin

FRONT END

20

.ANY

of board

sw

sfp

E.

1

A

D603.

IF AMPLIFIER AND AGC

(

)

Turn the AGC off.

( )

Hold the phono plug tip of the test signal cable against

F.

pin 1 of board speaker.

(

)

If you do not hear a tone, proceed to "Receiver' IFIAudio Circuit Board," Page 310. Check 0501,

IC501, Q502.0503, and associated circuitry.

( )

Turn AGC to FAST.

A tone should be heard from the

Insert the phono plug on the end of the 24" test lead

(

1

into the REC phono socket on the rear panel. Connect the other end of the cable as in Figure

241.

You should hear a tone at each 100 kHz point (3.600

(

)

MHz. 3.600 MHz, 3.700 MHz etc.) of the VFO dial.

( )

If you do not hear a tone, refer to "Receiver Front

End Circuit Board," Page 308. Check 0701. 0703, 0704 and the associated circuitry, the bandpass filters, and the injection of VFO and HFO signals.

Disconnect the 18

(

)

board.

~UQCC(~.

pF capacitor from the counter

1-8 on Page

0702.

.............................................

I

I I

I I I

I

I I I I I I I

I

I I I

I

I I I I I

I

-

BAND PASS

FILTER MIXER FILTER

A

ANTENNA INPUT HFO INJECTION VFO INJECTION

RECEIVER FRONT

-

BOARD G

Qml 0704 1

1ST 8.65 MHz ZND

- -

A

6-34

7

-

6.845

1%;

18.

10.

I

B,

END

MH*

-

5

-

5.5

A

-

UHF

3.395 MHz IPAGE INPUT TO

CRYSTAL FILTER

PIN1

I

I I I

I I

_----------------------------.

I

I I

I1

I

!!

I

I I

I

I I I

I

I I I

I

I I I

QMl

r

I

SWITCHING

&

I

MATCHING

I I I

I

LSB

GEN

I

Qffl8

I I I I

I

I I I

I----------------------------/

CRYSTAL FILTER

-

1

BOARDE

+

BOARD E

XTAL

FILTER

USB

GEN

Q613

1

I

I I

I.

-

QM3

SWITCHING

MATCHING

3.395 MHz

TEST SIGNAL. 3.395

DERIMDAS INPUTTO

EXPLAINED IN IFAMPLIFIE

THE TEXT

&

CW

GEN

Q6ll

v

2661.

-

ti

f

I

I1

I

I!

I

!

.

I,

1-1

I

I! I

I

I I

I

I I

I

I I I

A

MHz

RECEIVER

BLOCK

DIA

DIAGRAM

r.

RCalMR ANTENNA

EXTERWL

ALC

>

INPUT

ALC

BMRD

-

I---------------

I

DRIVER PRE DRIVER

H

BOARD

-

J

FROM

BOARD D

-

BORRDC

BANDPASS BALANCE0

FILTER

-

t

I I

MIXER

__C

I

BOARD D

L---------

-

I

-

:

I

-

!--.

TRANSMITTI

-

------

IF TRANShllTTER

BUFFER IF AMP

1

I I I I I I I I I

I

I I I I

I

I I I

t

I I I

I I

I

I I

<

KEY LINE

TX ENABLE

IBOARD BI

I

!

TIR

I

4

550

XTAL BALANCED

FILTER

-

SWITCHING

MATCHING

&

-

SW,TCX

I I

I

t

I

I I

I

1

VOX

I

I I

I

A

I I

I

!

- - -

UADj

-

- - - -

MODULATOR

-

- - -

- - - - - - - -

I

I I

7

I

L--_--

ACTIVE

AUDIO

BANDPASS

FILTER

RECEIVLR

'

TO

KEY

LINE&

.

I I

!

TRANSMITTER

I I

I

I----

SIKTONE

OSC

t

KEYING

CIRCUITS

AUDIO

I

!

I I I

;

I I

!

I

!

7

I

KN

<=

'IC PHONE

PATCH

I

I I

I

------4

I

TTER

I I

I

BMRDI

C=--------------------------------------------J

BLOCK

DIAGRAM

GEN GEN

GEN

TRANSMITTER TROUBLESHOOTING GUIDE

Refer to the 'Transmitter Block Diagram" (fold-out from

Page

268). which shows how signals flow through the

transmitter circuits, as you following pages. Each circuit board is outlined with a dashed

line, and the circuit functions are shown as solid blocks inside the outlines.

go

through the tests on

the

70

pTOEfNTT

YH:~E

LT

jov4C

:c:

50

jkF

*.--

This troubleshooting guide is divided into the following four sections: "Carrier GeneratorICrystal filter," "Transmitter

IF," "Driver," and "Power Amplifier." When you get the correct result for a test, proceed to the next one. not get the correct result, the last step will direct

proper part attention to some specific areas to check. When you turn to me "Maintenance" section:

TEST CIRCUIT PREPARATION

When a transmitter circuit board RF signal will be present at the output and input. Parts are furnished for a simple RF detector which can be used with a high input impedance voltmeter for signal tracing low level RF circuits. See Figure steps on the

CAUTIONS: follows:

of the "Maintenance" section and will call your

1.

Refer to any applicable parts of

"Troubleshooting Chart."

2.

Refer

"'Itages

mentioned

and Continuity Checks," Page Check any questionable diodes and transistors,

3.

See

6e

4.

me correct parts are installed.

5.

~~~d the

Schematic to better understand and analyze

your problem.

fold.out from Page

DO NOT use the detector on circuits Containing more

30

than

DO NOT use the detector on the PA circuit board or

its

VAC or 30 VRF.

output.

the

in

your

in

the

Page

274.

are each circuit is correctly wired and that

"circuit

Chart"

Transceiver

last

step. (Also

272).

~~~~~i~ti~~*~

is

functioning properly, an

4-1

and the accompanying

269.

I4

you do

you to the

tJw

and

check

the

at

the

areas

see

"Voltage

and study the

in-some

k'

To u, the RF detector, connect

DO NOT permit the terminal strip lugs to touch anything

while the detector

//COW~~

CARRIER GENERATORlCR'fSTAL

(

)

Connect a dummy load capable of dissipating 100

watts to the ANT socket on the rear panel.

(

I

Set

( )

Set the rear panel slide switch to COM.

'

)

lurn

Depress the PWR. TUNE, and ON buttons. All ofher

(

)

buttons should be released.

Refer to Figure

(

)

OLBU~E

(

1

Btaek

(

)

Gray wire to pin 6 of board

TO

IMP~DANCE HIGH

INPUT

CHASSIS

Figure

is

in use. The assembled terminal strip

yra?.&Afh~ap~e_@ . insulate

il

DC

2.

CONNECT VOLTMETER

COMMON LEAD TO CHASSIS.

4-2

it

as shown in Figure

.

--

VOLTMC~ER

MEGOHM

INPUT.

it:

OR

--

-{:!

HIGHERI

FILTER

the BAND switch to 3.5.

the

LEVEL

4-2

and connect the RF detector wires as

Red wire to the high input impedance voltmeter.

wire to the chassis of the Transceiver.

fully

E.

4-2.

'

I

i

I

E~=**---*****dl

Page 269

If there

(

)

"Carrier the RF detector to check for RF voltages at 0602, C of 0604, T601 (the terminal going to connector #22

indications at the three terminals of

low.

NOTE: DC voltage readings should only be made on board

when no RF voltage

Disconnect the gray wire from pin 6 or board

(

TRANSMITTER

(

)

Connect the gray wire of the RF detector to pin 24 of

board C.

If there

( )

"Transmitter IF Circuit Board," Page 298. Check for

RF voltages on the collectors of 0305, 0304, the

emitter of 0301 and pin 4 of

41.

(

)

Disconnect

is

no indication on your voltmeter, proceed to

GenIXtal Filter Circuit Board," Page 306. Use

B

is

grounded), and C of Q611. The

T601 will bevery

is

present.

E.

IF

is

no indication on your voltmeter, proceed to

IC301 (very low at pin

the

gray wire from pin 24 of board C.

of

E

FOIL

, ,

Figure

4-3

DRIVER

( )

Switch your voltmeter to a 10V or 15V range

(

)

Connect the gray wire of

(unhanded)

board.

If there

(

)

"Driver Circuit Board," on Page

detector to check for RF voltage at the cathode

(banded) end of diode D904 and at terminal 2 of the connector. Make sure you have +12 VDC on pin 5 of the board.

( )

Disconnect the gray wire from diode DW4.

end of diode Dm4 on the driver circuit

is

no indication on your voltmeter, proceed to

the

RF detector to the anode

3M).

Use the RF

P.A.

Use the following check to see if the P.A. transistors are defective. Figure component side. The shaded areas are connected to the secondary center taps of coils L952 and

4-3 shows the P.A. circuit board from the

L953.

(

)

Push

the HI PWR button in.

)

Connect the common lead of your voltmeter to the

(

chassis.

(

)

Connect the input lead of your voltmeter first to one foil and then to the other. At each foil, you should obtain the following "normal" reading. If you obtain a

"bad"

reading at either foil, all four final transistors should be replaced (these are only sold by Heath as a matched set of four transistors).

NORMAL

TX (HI PWR) 0.65V 1.2V

RX OV 1.2V

Refer to "P.A.Circuit Board." Page 312, for additional troubleshooting information about this section of the Transceiver.

Refer to "Power Amplifier Warranty" on Page 281 for the special one-year warranty on this circuit board.

BAD

-

(H

26

Connect the lead at the banded end of a IN191 diode

(#56-p)

2

(NS).

(d

Connect a and lug 2 (S-3).

(4

Connect a (S-1

(G

Connect

(S.1

(

!d

Connect a 12" (S-1).

to lug 4 6-2). Connect the other lead to lug

.Ol

pF disc capacitor between lug

yELiau/

12"

&

wlre to the

).

6REEN

a

12" bbk

).

*HIE

wire to the

8LRE

m

wire to the lower hole of lug 1

lower

hole of lug

-

1

(Sl)

4

3

Figure

4-1

RF DETECTOR

Refer to Figure

(q

Cut off and discard the indicated lug from the terminal strip you laid aside earlier.

('4

Connect

lug 4 (NS).

fi

)

Connect a lug

4-1

for the following steps.

a

.1

pF disc capacltor between lug 3 (NS) an*'

47

52

(yellow-violet-black) resistor between

2

(NS) and lug 3 6-2).

/INSULATED

\

WIRE

Figure

(&

Refer to Figure

the free ends of the three wires.

tX!

Lay the RF detector as~de.

/

4-1A

CRIMP

ONTO

END

BARE

AND

WIRE SOLDER

4-1A

and connect three sprlng clips to

It

will be used later.

4

r--"""----"'-----------------------------------------------

1

85-1416-1

BOARD "A''

DISPLAY CIRCUIT BOARD

7

TRANSFER PULSE

MEMORY LATCHES

RESET PULSE

IC 112

A&B

IC

113

I I I

I

117

IC

101

IC 112 lC 119

DISPLAY

TO COUNTERS

C&D

BLOCK

TO

DIAGRAM

Page

270

o~e-F***-******=]

DISPLAY TROUBLESHOOTING GUIDE

As

you

go

through the tests in the following pages, refer to

the schematic diagrams of the Counter and Display circuit

boards in the Maintenance section of this Manual, and to the

Display Block Diagram (fold-out from Page

shows

how signals flow through the counting and display

)circuits.

When you get the correct you do

Board" and "Counter Circuit Board" in the "Maintenance" section, which will give you some specific areas to check. When you turn to the "Maintenance" section:

Trouble in the counting and display circuits will usually widenced by a total or partial blanking of the display, an

incorrect display, or an unevenly lighted display.

got get the correct result, turn to "Display Circuit

1.

Refer to any applicable parts of the "Troubleshooting Chart."

2.

Refer to the "Voltage Chart" and check the voltages in your Transceiver at the points shown. Also see "Voltage and Continuity Checks," Page

272.

3.

Check any questionable diodes and transistors,

See

Page

4.

Be sure each circuit is correctly wired and that the correct parts are installed.

5.

Read the "Circuit Description" and study the Schematic diagram to better understand and analyze your problem.

274.

result,

proceed to the next test. If

270).

which

be

2.

If the entire display is blanked out:

)

Check for +I80 VDC at pin A on the display circuit

(

board. If the voltage A and check the voltage again. If the voltage at the end of the connecting wire low when connected, look for a short circuit on the display board.

If the

+I80

(

+5VDC at the convener input (the terminal under the AGC switch shaft bushing).

( )

If the

terminal, use voltage or continuity checks to trace the circuit back to discontinuity.

If the

(

)

converter circuit board. Check for a faulty transistor or an open diode.

3.

If all or part of a digit is not lighted, or the incorrect number is displayed, voltage checks or can

be

If the entire display has only three or four segments

(

)

lighted, check for circuit board. If the voltage is not present, use voltage or continuity checks back to 01, the

VDC is either absent or low, check for

+5

VDC is not present at the converter input

+5

VDC is present, look for the difficulty on me

used.

is

low, disconnect the wire at pin

is

then satisfactory, but

Ql,

the voltage source, to find the

IC substitution

+5

VDC at pin B on the display

+5

VDC source.

i

!

I

C

i

b

1

I

1.

If any segment of a number is brighter than the other segments, driver or by a short circuit on the circuit board (such

as

a solder bridge).

(

)

Interchange the suspected segment driver IC with one of the others. If both the overbright segment and the interchanged must be at fault and should be replaced.

If the overbright segment remains at the same location

(

)

after the driver IC's are interchanged, carefully inspect the circuit board for a solder bridge, leads unintentionally touching each other, and similar conditions.

it

is probably caused by a faulty segment

IC move to a new display digit, the IC

.

If there

(

)

display

(6606.4

Refer to the schematic diagrams and check the input

0

voltages and the ground connections at each counter, memory and driver IC's, and at the display tubes. If any of these voltages are incorrect, use a voltmeter to trace the circuit back to source. If the supply voltages are satisfactory, check the IC's by one of the following methods.

To check

A.

segment driver IC with another driver IC. If the fault moves with the IC,

is

no premix signal input to be counted, the

will show one of the preset frequencies

kHz,

6603.6

IC's by substitution, interchange the

kHz, or

it

6604.3

should be replaced. If the fault

kHz).

01. the voltage

IC in the

i

L-*--*=*:**Gaa

remains at the same digit. interchange the memory latch and observe the result. If the fault the same digit, interchange the counter

still

IC.

remainsat

Page

271

B.

To use voltage checks on a display string, refer to

4-4

Figure

digit of the display.

)

Check voltages at the segment driver output pins. The

(

voltages at pins connected to lighted segments should

be

lower than at pins connected to unlighted

segments.

If you know that a 3 should be displayed but segment

( )

G

(for example)

14

of the segment driver. If this voltage

value to the voltages at pins

whose tube segments are lighted), the tube

obviously than the other four pins, then the segment driver may be faulty. However, before making this decision, make

the following test.

(

)

Check voltages at the memory latch output pins. The decimal value of the decoded should be equivalent to the displayed number. Refer to the memory latch truth table in Figure determine the decimal value from the high and low

I

voltages at the four memory latch outputs. For

example, if pins are low, the value column shows a displayed should be a the display tube are operating

NOTE: The counter outputs cannot be checked with a

voltmeter as their outputs change rapidly with the count.

Use either an oscilloscope or the substitution method

described to check the counter outputs.

which illustrates the right-hand (sixth)

is

not lighted, check the voltage at pin

is

similar in

13, 12,

at

faoult. If the voltage at pin

10

and

15

are high and pins

3.

If so, the segment driver and

sat~sfactorily.

11

and

BCD

output voltage

3,

and the number

14

10

is

4-4

16

(all of

higher

and

is

to

9

VlSl

IPARTl

+SVDC~L6

+5VDtd

t5VDC

SEGMENT

MEMORY

14

COUNTER

1

VALUE

MEMORY

LATCH

D

DRIVER

LC151

LATCH

IC103

IC102

LATCH

TRUTH

Figure

4

I

PINS

L H

TABLE

4-4

LOW-

-

L=

LESS

H-

MORE

LIGHTED

THAN

0.8VOC

THAN

1.5VDC

Page 272

--iq

VOLTAGE AND CONTINUITY CHECKS

To measure voltages, use a voltmeter with a high input

(11

impedance input impedance may load down a circuit and cause the readings to

An ohmmeter

determining the continuity of conductors and inductances,

and making

transistors (as in "Checking Transistors and Diodes," Page

274).

First, before you check a component on any circuit board, check for the presence of the proper DC input voltage and check the ground connections from the circuit board connectors to the chassis. These are shown on the individual schematics for the circuit boards in the section Page 275 and on Figure 5-1 (fold-out from Page

3231.

Check

all nongrwnded circuit board connectors to make sure there is not a chassis or to adjacent pins. Do this because one fine strand from a conductor can sometimes protrude and touch an unintended location, thus causing a short circuit. These are usually difficult to see.

When you are told to check a component, refer to the part

of the "Maintenance" section which deals with the circuit board upon which the part is located; then measure the

megohms or higher). A meter with a low

be abnormally low.

is

very useful for measuring resistors,

a

rough check of the serviceability of diodes and

"Ma~ntenance"

hort circuit (zero resistance) to the

voltages around the component and check them against

It

those shown in the ''Voltage Chart." necessary to use the extender board to gain access to the points to be measured. Any voltage deviation of more than 20% should be considered as possibly indicating some sort of malfunction.

There can be various causes of a voltage variation. For instance: the supply voltage may have changed, there may be a malfunction in the Transceiver's power supply, some resistor between the test point and the voltage source in the Transceiver may have changed value, or a bypass capacitor may have short circuited. Use your voltmeter and trace the voltage path back until you get a normal voltage reading.

is

When this point can be limited to a very few components, which can then be thoroughly investigated.

CAUTION: When you check transistors, be very careful that you do not probe. This can destioy a transistor instantly.

I

.

~

The complete absence of a designated voltage indicates a poorly soldered connection, a break in the foil, a power supply failure, or a similar problem.

In such cases, turn the Transceiver OFF and use your ohmmeter path to the voltage source. Use the "X-Ray View" (see "Maintenance," Page 275 and the schematic diagram to

determine where the path

touchtwo leads at the same time with the meter

Ion

reached, the probable causes of trouble

~

~..~

.....

~

.

its

RX1 scale) to check thecontinuity of the

is.

will usually be

Page

273

TEST

This chart uses selected parts of the "Test and Adjustment" section to check circuit boards. It will be most useful for the type of difficulty that shows up after the Transceiver has

.

~,

Transmitter au "Transmit Audio Vox ampl., keying, relay

been in operation for some time. Refer first to the

"Function" column and locate the function that operating properly on proper tests (and adjustments in some cases) as described in the next column.

Be sure to on Page

sse "After you localize the trouble to enearea:"

264.

CHART

is

not

ywr Transceiver. Then perform the

G

C

J

H

Receiver front end,

pass filters.

Transmitter IF amps.,

bandpass filters

ALC,

Driver

Power Amplifier

band-

"VFO Shift Ad'ustment"

"Receiver Alignment"

"Low Power Transmitter"

"P.A.

Circuit Board"

243

244

Page

274

r-~**.*-~***:*&

CHECKING TRANSISTORS AND DIODES

SILICON BIPOLAR TRANSISTOR CHECKING

To check a transistor accurately, you should use a transistor checker. ohmmeter to determine the general condition of any of the bipolar transistors in this kit. The ohmmeter used must have at least 1 volt the diode junctions in the transistor being tested.

To check a transistor with an ohmmeter, proceed as follows. NOTE: Identify the transistor leads on the "Pinout Diagrams" on

1.

2.

3.

4.

Howwer, if one is not available, you can use an

DCg,at

Page

Unsoldw and remove the transistor from the circuit.

Set

the ohmmeter to the RXIMX) range.

Connect one of the ohmmeter test leads to the base (B) of the transistor. Touch the other meter lead to the emitter readings should be the same, but may be either high or low. If one reading is high and the other low, the transistor should be replaced.

Repeat step

probe tip to exceedthe

tieshhsf

~.

~~

276.

(El and then to the collector (C). Both

3

with the test leads reversed.

Method

1.

2.

3.

4.

5.

Method

1.

2.

3.

4.

5.

6.

1

Remove the device from the circuit.

R

Set your ohmmeter to the Connect the common meter lead to the gate and the

hot lead to the source.

If the device is good, a reading near infinity will obtained. If you do not meter leads. If you do not get a reading near infinity with the meter leads connected either way, the device should

be

replaced.

X 10 K range.

get

this reading, reverse the

2

Remove the davice from the circuit. Set your ohmmeter to the R X 10 K range. Connect the gate to the source. Connect the common meter lead to the gate and source and connect the hot lead to the drain. The meter reading should be in the lower part of the meter scale.

If the reading is not in the lower part of the meter scale, the device should be replaced.

be

NOTE: In the unusual all high, no matter which ohmmeter lead is connected to the be, the transistor should be replaced.

case

when the readings are all low or

MOSFET AND JFET CHECKING

Insulated gate receiverllf audio circuit board, and at 0701 and Q704 on the receiver front end circuit board. Q1202 and 01203 on the VFOIbuffer circuit boards. Usually, any defect in these devices is found to be an internal short circuit between the source and the gate of the

JFET (between the source and one of the gates of the

MOSFET). These devices can be checked for Serviceability by one of the two following methods.

type

MOSFET's are used at Q501 on the

JFET's are used at

DIODE CHECKING

To check a diode, unsolder one end from the circuit board, pull the lead up out of the circuit board hole, and proceed as follows:

Set the ohmmeter on

1.

2.

Connect one of the ohmmeter test leads to the

cathode (banded) end of the diode. Connect the

test lead to the other end of the diode. Note the reading. Then reverse the meter leads and take another reading. One reading should be high and the other low

(at least

high, the diode should be replaced.

10:l). If both the readings are either low or

the

R X 1000 range.

other

MAINTENANCE SECTION

INDEX

Pin-out Diagrams

ldentification Charts Circuit Board Service Policy VFO and Buffer Circuit Boards Converter Circuit Board

Display Circuit Board Counter Circuit Board

HFOIPremix Circuit Board

Transmitter Transmitter IF Circuit board

Driver Circuit Board

VFOIFilter Circuit Board ALC/Output Circuit Board

Carrier

GenIXtal Filter Circuit Board Receiver Front End Circuit Board Receiver

P.A. Circuit

This part of the Manual presents, for each circuit board, a section which contains the Schematic diagram, an "X-Ray etc.) on the proper "X-Ray View" or the View," a "Voltage Chart," a "Troubleshooting Chart," and a "Circuit Description." The "X-Ray View" permits you to simulate viewing both sides of the circuit board B. Locate this same number in the "Circuit simultaneously so you can easily trace the foil between components. "Parts List."

IFIAudio Circuit Board (F)

. . . . . . . . . . . . .

. . . .

. .

. . . . . . . . .

. .

.

. . .

. . . .

. .

.

. .

. . .

. .

. . .

. .

.

(Al

. . . . .

(D)

AudioIReg Circuit Board (B)

(C)

(J)

. . . .

.

. . .

. . . .

. .

. . . . . . . .

(K) .

.

. . .

(E)

(G)

.

Board

(H)

.

. .

.

. . . . . . . . . . .

A.

pattern Component Number"

. . . . .

,

.

. . . .

.

. . . . . . .

. .

. . .

. .

. . . . .

. .

. . .

.

. . .

.

. . . . . .

.

. . . . . .

. . .

.

. .

.

. . .

. . . . . . . .

.

. .

Find the circuit component number (R5, Q2,

Schematic.

. .

.

. .

.

. .

.

. .

.

. . .

. .

.

. . .

276 279 281 283 286 288 291

294 296 298

300

302

304 306

308 310 312

column of the proper

The pin-out diagrams and Identification Charts provide a summarlzed reference to all the solid-state devlces used in will find the Pan Number and Description, the Transceiver. which must be supplied when

To find the Part Number of a component for the ordering a replacement part:

purpore of

Adjacent to the circuit component number, you

C.

yw order a

replacement part.

Pin-out

Diagrams

Display Tubes and Integrated Circuits

VlfWED

FROM FRONT

SEGMENT PIN NUMBER

DECIMAL

ANODE

V151, Vl52. V153.

PART N0.411-286,

SP-352

8

IN01 USE01

10

IN01 USED1

TkBLI

TRUTH

BCD COUNT SEQUENCE

IA IB IY 2A 28 ZY

ICllZ

PART NO. 443-1

SN7400N

IA

10 NC IC ID IY GND

ICli9

PART NO. 443-2

SNldZON

CND

NOTE:

1,

=

ln+l ; BIT TIME AFTER CLOCK PULSE

BIT TIME BEFORE CLOCK PULSE

IC117. IC118

PART NO. 443-5

SN1473N

IC113. IC114. ICII5, IC116

PART NO. 443-7

SN14PON

rz-lwa-u=.irla

Page

277

IC103' ICLo5'

IC109, IClll

PART N0.443-13

SN7475N

IC107'

Q

J

<LOTI:

K

lClOl

PART NO. 443-70

SN74HIO3CU

K

CLOCK

NOTE;

J

NOTE:

tn . BIT TIME BEFORE CLOCK tn+l - BIT TIME AFTER CLOCK

NEGATIVE-GOING TRANSITION.

TRUTH TABLE

1.

-

BIT TIME BEFORE

CLOCK

I

-

IBCDI (SEE NOTE1

PULSE

BIT TIME AFTER

PULSi

CLOCK

TRUTH TABLE

'

ASYNCHRONOUS INPUT: LOW INPUT TO CLEAR SETS

QA, Qg. QC AN0

Qg

LOW.

OUTPUT TO CLOCK-2 INPUT.

IClOZ. IC104. ICl06.

QA

CONNECTED

IC108, lCll0

PART NO. 443-628

74196

Page

278

,~c-j=**

ORIVi OUTPUTS

r

VCCf

IC151. IC154.

PART

ga

bcd

-=*:-*g

e

CURRENT

PROGRAMMING'

INPUT

RIPPLE

1

BLANKING

INPUTIRIPPLE BLANKING

OUTPUT

BLANKING

-

ZERO SUPPRESSION

IBllRBal

INPUTIRBII

NOTE: LOGIC

"I"

HIGH TTLIDTL STATE.

DEFINED AS THE LOW OR CURRENT SINKING STATE IDISPLAV

ON

ON ALL INPUTS AND RBa IS DEFINED AS THE

STATE].

X

IS DEFINED AS "DON'T CARE" CONDITION

"0"

LOGIC

ON OUTPUTS

a-9

IS

Identification Charts

9$P

$1"

4~"?,~UJ*u=

-

---

,r-

w.

b

y->.

--:::-

ti

P

3

a

2

*HAS

WIDE

LEADS

Circuit Board Service Policy

IN WARRANTY - When any of the circuit boards listed below are returned to any Heath service facility within days of the date of your invoice, defective parts will be replaced without charge for pans or labor. A circuit board that requires service due to causes other than will be repaired at the fixed charge listed for that circuit board.

OUT OF WARRANTY expires, any of the circuit boards listed below will be repaired by a Heath service facility at the fixed charge listed

plus the cost of pans replaced.

SERVICE FACILITIES - Service facilities are available at our factory and at circuit boards used in the Model SB-104 Transceiver.

CIRCUIT BOARDS - The Circuit Board Service Policy applies to the following circuit boards:

CIRCUIT BOARD

VFOIBuffer (entire assembly) A Counter 5.00 B Transmitter AudioIRegClator 5.00

C

Transmitter IF 10.00 D HFO/Premix 5.00

E

Carrier GeneratortCrystal Filter 5.00

F

Receiver IFIAudio 10.00

G

Receiver Front End

H

Power Amplifier

J

Driver

K

FiltertALC Display

*Pl,us parts charge when out of warranty

POWER AMPLIFIER WARRANTY -Within one year from the date of your invoice, the power amplifier circuit board. completed according to the instructions in the Assembly Manual, may be returned to the factory or to a

-

After your 90-day kit warranty

Heathkit Electronic Centers to service the

defective parts

SERVICE

LABOR FEE*

$1

5.00

90

Heathkit

Electronic Service Center for repair or replacement, at our option. The power amplifier circuit board must be returned for warranty replacement of the output transistors.

After one year, a matched set of the four transistors used on the power amplifier circuit board may be purchased from the Heath Company for

balancing the transistor characteristics, they are available

set

only as a

HOW

A special circuit board packing carton included in Pans Pack #12 of your Transceiver. This

collapsed canon which on the sides so it will be easily recognized among other pieces of inwming mail and receive priority handling. Save both the carton and some loose packing material for future use, should information in the package:

Ship the carton by insured parcel post to "Heath Company,

Benton Harbor. Michigan, 49022" or to any one of the Heathkit Electronic Centers listed in the current Heathkit

catalog.

IMPORTANT

circuit boards named. If the problem appears to be elsewhere and cannot be resolved with the Manual troubleshooting suggestions, check with our Technical

Consultants Section at the factory or at your nearest

Heathkit Electronic Center before returning the kit or any

components for service.

of four.

TO RETURN CIRCUIT BOARDS'

it

1.

Your name, address and, zip code.

2. A letter describing the symptoms observed in your Transceiver, and copies of any prior

correspondence

3.

The chassis series number (find this on the blue and white label).

4.

Date of purchase and invoice number.

5. Authorization for us to return your circuit

board COD for the service, pans, and shipping

,-hzmoc

"..-.>""

-

$50.00. Because of the necessity for

(#380-846) has been

is

the

is

packed flat and has red rectangles

be necessary. Include the following

The policy stated above applies only to the

Page

282

SCHEMATIC OF THE

HEATH KIT^

TRANSCEIVER MODEL

NOTES:

1.

ALL RESISTORS ARE 112 WATT UNLESS OTHERWISE SPECIFIED.

VALUES ARE IN

2. CAPACITOR VALUES LESS THAN I ARE IN liF AN0 HIGHER ARE IN pF UNLESS OTHERWISE SPECIFIED

3.

THE BANDSWITCH IS SHOWN AT THE THE MODE SWITCH AT LSB.

4.

REFER TO THE PIN-OUT DIAGRAMS AND IDENTIFICATION CHARTS FOR INFORMATION CONCERNING TRANSISTORS.

DIODES. AND INTEGRATED CIRCUITS

5. REFER TO THE APPROPRIATE PARTS LIST FOR CROSS~REFERENCE BETWEEN SCHEMATIC COMPONENT DESIGNATIONS AND PART

NUMBERS.

SI

IOHMSl. K-1.000: M=1,000,000.

SB-104

VALUES OF

3.5

MHz POSITION AND

IICsi.

1

6.

CHASSIS WIRING - SEE FIGURE 5-1 ON FOLD-OUT FROM PAGE 323

7.

SYMBOLS:

+%-

A PLUG-IN CONNECTION.

=

CIRCUIT BOARD GROUND.

;

CHASSIS GROUND.

0

=

IDENTIFIED CIRCUIT BOARD HOLES.

-

CIRCUIT BOARD EDGE CONNECTOR.

FERRITE BEAD.

@

-

PHONO SOCKET.

BIPOLAR TRANSISTOR

1

GATE

GATE 2

MOSFET

DRAIN

SOURCE

.

DRAIN

J

SOURCE

FET

VFO

and

Buffer

Circuit Boards

TROUBLESHOOTING CHART

*

SYMPTOM

Frequency drift or warble.

Less than VFO output.

.4

to

.5

,

POSSIBLE CAUSE

1.

Check all mechan~cal connections.

2.

3.

4.

VDC

NOTE: Heath part numbers that correspond to the circuit

component numbers will be found in the Parts List starting

on Page

11

of this Manual.

1.

cemented capacitors on oscillator

Check

circu~t board. Shorten wires to coil

them securely.

Resolder bare wires from tuning capacitor solder lugs.

Refer to "VFOIBuffer Trouble shooting Guide."

C1201

L1201

and resolder

to circuit board

-

Page

284

X-RAY VIEWS

VFO BOARD BUFFER BOARD

(Shown from component side)

VOLTAGECHARTS

;hewn

TRANSMITTER VOLTAGES NOTFS:

from component side)

(~20%)

a

DC

VOLTAGE IN RECEIVE OR TRANSMIT MODES

@+J=****=.:wi

Page

285

CIRCUIT

A

field effect transistor is used in a type of Hartley oscillator

circuit in

C1201

compensating capacitors are used determining circuits. The remaining part of coil used for feedback to maintain oscillation.

Diode

C1211

frequency so the output carrier frequency remains the same

when you switch sidebands.

me VFO. Part of coil

(the main tuning capacitor), and fixed temperature

Dl201

acts as a switch to add or remove

from the circuit. These capacitors shift the VFO

L1201,

Dl201

variable capacitor

in-the frequency

is switched by the

DESCRIPTION

LIZ01

C1209

and

polar~ty of the voltage applied to its anode by the pushbutton switch.

voltage to the drain of

The output of oscillator

is

source-follower transistor

impedance matchingdevice.

01204

compensated by diodes

R1232

and

Q1205

controls the buffer output.

ZDlZOl

are fix&tuned amplifiers, temperature

is a zener diode to regulate the

Q1202.

01202

Q1203,

Dl202

which acts as a buffer and

and

D1203.

LSB

is

coupled to

Variable resistor

i

1

Refer

SCHEMA1

to

Page

282

for

Schema1

------------------------------r---------------

:OSCILLATOR CIRCUIT BOARD:

rm---m--------------------

I

CJIOP

41202

Cr2I4

\I

I,

10

z01201-

IO".

-

AL

v

OUTPUT

RId06

47

1

I I

I I I I

I

I I

I

!

I

r,,

I

r--------'

IBUFFER

I

p--------.

I

<

I I

I

BO,

001

I

I I

r

Schematic symbols.

GRAY

DIODES

Dl201 D1202, Dl203 ZD1201.10V.

TRANSISTORS

01 202.01203

01

204

(11 205

QUANTlTY

1

2

1

2

1

.

TYPE

IN191 lN4149

VR-1OA

MPF105 2N3393 2N3638A

HEATH PART NO.

56-26 56-56 56-67

417-169 417-1 18

7-234

41

+.

I

I I I

I

DISPLAY AND COUNTER

I I

I

I I

1 I

Refer to

SCHEMATICS

Page

282

for

Schematic

symbols.

!

A

.

OUAN-

DIODES

D101-Dl10

TRANSISTORS

0101 1 2N2369 417-154

INTEGRATED CIRCUITS

lClOl IC102.IC104. IC106. IC108, IC110

IC103, IC105, IC107, IClW, IC111

IC112 IC113-IC116

IC117, IC118 IC119

IC151-IC156

TlTY

10

1 5 5

1

4

2

1 6

-

TYPE

lN4149

SN74H103 74 196 SN7475N SN74WN SN7490N SN7473N SN7420N

DD700

HEATH

PART NO.

56-56

44570 443628 443-13 4431 443-7 443-5 443-2 443602

Converter Circuit Board

TROUBLESHOOTING CHART

SYMPTOM

Output voltage low.

No output voltage.

DIODES

D851

-D854 4 IN2071 57-27

TRANSISTORS

POSSIBLE

1. 0851,0852. T851.

2. 5 volt input low.

1.

2.

3.

4.

5. Solder bridge on

QUAN- TYPE HEATH

TIT? PART NO.

CAUSE

No input voltage. 0851,0852. T851. D851 - D854. C851 - C857.

board.

Q851, 0852 2 MPSU05 417-224

I

Page

287

X-RAY VIEW

(Shown

NOTE:

component numbers will

on Page

Heath part numbersthat correspond to the circuit

31

of this Manual.

from

component

be

found in the Parts List starting

side)

CIRCUIT DESCRIPTION

VOLTAGECHART

(Shown

TRANSMITTER VOLTAGES NOTES:

1.

BANDSWITCH IN 3.5POSITION MODE SWITCH IN TUNE POSITION

2.

METER SWITCH IN

3. 4

MtC/CW-LEVEL FULLY COUNTERCLOCKWISE

0

DC VOLTAGE

from

component side)

ItZO%I

PWR

POSITION

IN

RECEIVE OR TRANSMIT MODES

The converter consists of an oscillator, formed by

0852, T851,

circuit oscillates voltage on the secondary of through

and associated feedback components. This

at

approximately

D854

to produce the required

25

kHz,

and the high

T851 is rectified by

180 VDC. L851

SCHEMATIC

0851

and

0851

and

the associated capacitors filter the off of the input line. The converter is enclosed

box to prevent the harmonics of

with

the operation of the remainder

25

kHz switching noise

25

kHz from interfering

of

theTransceivw.

in

a shield

I".

Display Circuit Board

TROUBLESHOOTING CHART

SYMPTOM

In one digit, one segment brighter than others.

One segment will not light.

Display will not light.

Display incorrect.

l7Gzl

POSSIBLE

The associated segment driver

IC.

1.

Defective display tube.

2.

Associated segment driver

I

C.

3.

Tube pin mounting sockets.

1.

5V

or

2.

Segment driver.

3.

Display tube.

1.

Signal from counter board.

2.

Wiring error between counter and display boards.

X-RAY VIEW

CAUSE

180V

missing.

(Shown

from

printed

side)

Page 289

TRANSMITTER

NOTES:

1.

BANDSWITCH IN 3.5WSITlON

MODE

2.

METER

3.

4.

MICICW-LEVEL

0

OC

VOLTAGES

SWITCH

VOLTAGE

I+ZO%l

IN

TUNE

POSITION

IN

PWR

POSITION

FULLY

COUNTERCLOCKWISE

IN

RECEIVE

OR

TRANSMIT

MODES

NOTE: Heath part numbers that correspond to the circuit

component numbers will be found in the Parts Liststarting

31

on Page

Refer to the Display

of this Manual.

Circuit Board Schemat~c, fold-out from

Page 286.

CIRCUIT DESCRIPTION

The display board receives the outputs of five memory The schematic diagram shows segment driver outputs

latches (IC's 103, 105, 107, 109 and 11

,

board

(A).

The four BCD outputs of each memory latch are display tubes. The driver output voltages for lighted processed by a segment driver so the appropriate segments of

its

display tube are turned on. The firs display digit hasa segment driver (IC156l which witch. This digit or reads 1 or

is

in the megahertz position and is blank.

2,

as appropriate.

is controlled by the Band

1

)

from the counter

through

G,

which drive similarly lettered segments of the

segments are lower than the voltages for unlighted tube segments. Each tube requires an anode voltage of 180

is

which

This

supplied by the converter from

is

the only high voltage used in the Transceiver.

its

5 VDC input.

A

VDC.

Page

290

1.

BAND SWITCH AT 3.5MHZ POSITION.

2.

ENCIRCLED LETTERS ON PLUG-IN BOARDS REFER TO UNDER-CHASSIS LABELS.

SIMPLIFIED COUNTER AND DISPLAY SCHEMATIC

(From Figure

2

PC

5-1)

A

Counter Circuit Board

TROUBLESHOOTING CHART

SYMPTOM

Readout of preset frequencies

incorrect

One digit incorrect.

Will not count (preset frequency display OK).

(6606.4.6603.6.6604.3)

POSSIBLE

1. Time base not running.

2.

3.

1. Associated counter IC.

2.

3. Display board connections.

4. Chassis wiring.

1. Premix signal missing or

2.

3. IC101.

CAUSE

IC-112 thru IC-119.

5V

missing.

Associated memory IC.

low in voltage.

Q101.

~

Page 292

I~b=*='--*=*:*91

CIRCUIT DESCRIPTION

+5VDC-416

+5v~cl14 COUNTER

SEGMENT DRIVER

lCL5l

IC102

I

1

The function of this card difference frequency of the mixed HFO and VFO signals) and to place the Figure

4-4 shows a counter, memory latch, segment driver and display tube chain. The truth table for the memory latch output pins

The premix signal is amplified by

prescaler IC101, which divides the input signal by four. This

.

division is necessary to reduce ambiguity and flicker in the

last (100 Hz) digit of the display, and to insure that the

counters will be operating below their maximum frequency

limit.

A stable crystal oscillator as a

1

MHz time base. Six integrated circuits (IC113 through

IC118) form a divider string whose 100 Hz. 50 Hz. 25 Hz.

and 12.5 Hz outputs are applied to

112C to produce the gate, reset and transfer pulses. The gate pulse controls the length of time the counter will accept the input signal for counting. The transfer pulse allows the data in the counter to enter the memory latches, and the reset pulse resets the counters and

munt in the proper format for display.

is

to munt the premix signal (the

included.

(IC112A. 1128 and Y101)

prescalers.

0101 and applied to

is

used

IC's 119A. 1198 and

VALUE

MEMORY LATCH PINS

L-

H L

6 HHL

1

8

P

MEMORY LATCH TRUTH TABLE

H H

HHH HLL H H

Figure

4-4

10000.0 kHz FALSE ZERO FREQUENCY

3393.6

kHz

6606.4 PRESET FREQUENCY

US6

LSB 3393,

W

C

H-

LSB BF0 FREQUENCY

BFO

-

3396.4 kHz 6603.6 kHz 3395

LESS THAN O.8VDC

MORE THAN 1.5VOC

PRESET

6

6606.4

6604.3

1

As the premix signal is above the signal frequency by an

amount equal to the BFO frequency, the presettable decade

counters are programmed to start counting from a preset number below zero by To calculate this preset number, the BFO frequency subtracted from 10.000.0 kHz, which is used as an "arbitrary zero." See Figure 4.5.

10,000.0 kHz as the false zero because the counters use only

five digits of the display and the

An example follows for a 3900 kHz LSB signal:

If

the counter IC's are preset

signal frequency of 7293.6 kHz

the amount of the BFO frequency.

It

is

convenient to use

"1" will not be seen.

at

6606.4 kHz and the premix

is

counted, the total for

is

Figure

4-5

Page 293

11 3 10 4

NUMERICALVALUE 8421

LOGICALVALUEXLHHL LHHL

PRESET VALUE

*

L=LOW H~HIGH, LOWS NOTSIGNIFICANT

TOTAL OF HIGH VALUES

EQUAL PRESET VALUE.

display

is

13900.0 kHz as shown in Figure 4.5. However, as

6

there is no provision for displaying the figure

11 3 10

4

8421

6

11

3

10 4 11

8421 LLLL

0

"1," the display will read 3900.0. which is the correct signal frequency. The following tabulation shows the calculations:

HFO for 3.5 MHz band

12395.0 kHz

VFO 51 01.4

Premix 7293.6 kHz

False zero 10000.0 kHz BFO for LSB Preset

3393.6

-

6606.4 kHz

Reset frequency 6606.4 kHz Counted frequency (Premix)

7293.6

Display (Signal) frequency '13900.0 kHz

'The signal frequency will be displayed

the "1" cannot

be

seen.

as"3900." as

NOTE: The first of the six display digits is controlled by the BAND switch and is blank, 1, or 2 as appropriate. This

discussion deals only with digits two through six, controlled

by the counter

BCD (binary-coded decimal)

counter

(which have decimal values of 8, 4, pins is grounded,

positive, significant. The values of the highs, if any, each

IC are added together to determine the preset number

for that IC. Refer to Figure

the following explanation of how the counter programmed for the

IC110:

la.

is

used to program each

IC for a preset frequency

it

is

logically low, and if not connected or

it

is logically high. Only the high pins are

at

pins 11. 3. 10, and 4

2,

and 1). If any of these

at

the pins of

4-6, the xhematic diagram, and

IC's are

LSB preset frequency of 6606.4 kHz.

Pins 11 and 4 are grounded and therefore have

no value. Pins 3 and 10, with values of 4 and 2 respectively, are not connected and are therefore high.

so

the figures are significant. 4 + 2 = 6 as

IClOB:

the preset value for this

Same as ICllO.

IC.

3

10 4

11 3 10 4

LOWER SIDEBAND PRESET.

8421 LHHL LHLL

6

IC106:

8421

Figure

4

46

All pins are grounded and are therefore low, the preset value is 0.

IC104: Pin 11

grounded through

is

grounded directly and pin 4 is

R107, so there is no value these pins. When the front panel LSB button is pushed, a positive voltage is connected to pin 22 of counter circuit board A. This voltage is applied to the anodes of

0105 and 13102, which carses them to conduct and pass the voltage to pins 3 and 10 of the IC. These pins are therefore

IC102:

high and have values of 4 and 2,

value of the

Pin 11

IC

is

6.

is

grounded directly, and pins 10 and

so

are grounded through R105 and R104. so these

pins are low and without value. The positive

LSB voltage is applied through

Dl09 to pin 3, which becomes high and has a value of 4. The preset value for this

The presets for the second, third and display are fixed

as

"660"

remaining two digits change as the

IC is therefore 4.

fourth digits of the

(IC's 110, 108 and 106). The

US$, LSB, and buttons apply positive voltages through the diode matrix to the pins of

IC104 and IC102. The USB preset frequency will

be 6603.6 because the positivevoltage from pin 23 of board

A

will be applied to IC104 pins 10 and 4, total value 3. and

IC102 pins 3 and 10, total value 6. The

will be 6604.3 because the positive voltage will

from pin 24 of board A to

IC104 pin 3, value 4. and to

CW

preset frequency

be

IC102 pins 10 and 4, total value 3.

IC's 103, 105, 107. 109 and 111 are memory latches which

store data from the counters during counting periods. This eliminates flashing digits which would otherwise be present

during counting periods. During the transfer pulse, the BCD

count present at a

memory, which retains

counter output is transferred to the

thecount at itsoutput until the next

transfer pulse.

are

The memory outputs

connected to the segment drivers, which are located on the display circuit board. The significant outputs are logically high. Each memory output

is

coded using BCD in a manner similar to the decimal

coding described for presetting the counters.

so

at

the preset

4

CW

connected

VOLTAGECHART

X-RAY

VIEW

TRANSMITTER VOLTAGES NOTES:

1.

BANDSWITCH IN 3.5 POSITION

2.

MODE SWITCH METER SlhlTCH Ih PlhR POSITION

3.

4.

MICICW-LEVEL FULLY COUNTERCLOCKWISE

0

DC VOLTAGE IN RECEIVE OR TRANSMIT MODES

[km)

IN

TUkE POSITION

..

.

(Shown

from

ccmponent

side)

HFO

PREMIX

HFOPremixer Circuit Board

TROUBLESHOOTING CHART

L

SYMPTOM

POSSIBLE CAUSE

HFO will not oscillate or

output voltage very low

(all bands).

HFO inoperative, one band

only.

I

Premix output low, all bands (HFO

is

OK).

Premix output low, one band

(HFO is OK).

Premix output low. (HFO

is

OK).

t

10

meters.

1.

Bandswitch wiring.

2.

I

lV missing.

3.

Q405.

1.

BAND switch.

2.

For the band concerned, the associated crystal, transistor. switching diodes, coil.

1.

VFO signal low or missing.

2.

0406, 0407.

1.

BAND switch.

2.

Filter components associated with the band.

VFO filter board components.

.

Refer to the "X-Ray View" and "Voltage Chart" (fold-out

from this page).

CIRCUIT DESCRIPTION

Page

295

The function of these circuits crystal-controlled injection signals, and to mix these signals gain, and the resulting signal is applied to the premix with the VFO signal to obtain the premix signal. balanced mixer.

0401, 0402. Q403, oscillators are crystals. filtered by diode-selected

The crystal oscillator signal is amplified by

and

Q404

diodeselected,

are used as oscillators. These

as are the proper oscillator

is

to generate routed to the receiver circuitw.

0405,

~iodes mixer, which combines the HFO and VFO signals to create the premix signal. The output of the balanced mixer is

Q407.

and and counter circuits.

D427, D428, D429,

The resulting output is used

Q406

provides additional

and

D430

form a balanced

bandpass filters, and amplified by

to

drive the transmitter

Em:$

I I

I

I I

I

I I

I

I I I

I

I I

8.7

------

1

"

5---

-,-----,------------

:

asoi

,

,000

HFO/PREMIX

CIRCUIT

BOARD

?

-,

-----------.

:

,7

---------------

0420

r,

n

9

z

,I

----I---.

I

I,,-------,,,,,,,,,-----------------,,---------------------------------------..---

CIRCUIT BOARD D

Refer

to

Page

282

for

Schemz