Drake R-4B Instruction Manual

TABLE ~~ CONTENTS

Specifications

SECTION I,

1.1

1.2

1.3

SECTION II, Installation

2.1

2.2 Locating and Mounting

SECTION III, Control Functions

3.1

3.1.1

3.1. 2

3.1.3

3.1.4

3.1. 5

3.1. 6

3.1. 7

3.1. 8

3.1. 9

3.1. 10

3.1.11

3.1.12

General Description Introduction Auxiliary Equipment General Electrical Characteristics

Unpacking

Front Panel Function Passband Main Tuning Dial Main Tuning Knob A.F. Gain SSB/CW-AM Notch R.F. Gain Pre-selector Band XTALS S-Meter

1-3

6 6

10 10 10 10 10 11 11 11 11 11 12 12 12

3.2

3.2.1

3.2.2

3.2.3

3.2.4

3.3

3.3.1

3.3.2

3.3.3

3.3.4

3.3.5

3.3.6

SECTION

4.1

4.2

4.3

4.4

Side Panel XTAL/VFO S-Meter Zero Notch Adjust

Phone Jack

Rear Panel

ACC. Power

Inj. Mute

Anti-Vox

Spkr.

ANT.

IV, Operation

Basic Control Settings

SSB or DSB Suppressed Carrier Reception CW Reception AM Reception

12 12 12 13

13 13 13 13 13 13

14 14 14

TABLE OF CONTENTS (cont'd.)

SECTION

4.5

4.6

4.7

4.8

4.9

4.10

4.11

SECTION

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

5.10

5.11

5.12

5.13

5.14

IV, Operation (cont'd.)

RTTY Reception Noise Blanker

Notch Dial Calibration Additional Tuning Ranges Fixed Frequency Operation

VHF Reception

V, Principles of Operation

R.F. Amplifier Pre-mixer First Mixer Second Mixer

I.F. System Detection Systems Audio Output AVC System S-Meter

Noise Blanker Crystal Calibrator Power Supply VFO Indicator Light Block Diagram

15 15 15 16 17

18 18

20 20 20 20 21 21 21 21 23 23 24

SECTION

VI, Servicing

6.1

6.2

6.3

6.4

6.4.1

6.4.2

6.4.3

6.4.4

6.4.5

6.4.6

6.4.7

6.4.8

6.4.9

ILLUSTRATIONS

Figure

Figure Figure Figure 4 Figure Figure

5 6

Removing Covers Tube Replacement Troubleshooting Alignment Instructions 25 KHz Calibrator 50 KHz Oscillator 50 KHz I.F. Crystal Filter and Filter Match Transformer 5595 KHz Oscillator

Antenna, R. F., and Injection Circuits Notch Filter Passband Tuner Bias and S-Meter

Using the R-4B with the TR-4

transceiver Mounting Options Front View of R-4B Rear View of R-4B Accessory Crystal Frequencies

Preselector Tuning

27 27 27 27 30 30 30

31 31

32 33 33 35

;

7 7

TABLE OF CONTENTS (cont'd.)

ILLUSTRATIONS (cont'd.)

Figure 7 Figure Figure Figure 10 Figure 11 Figure 12 Figure

Selectivity Curves

Notch Effect

Block Diagram of R-4B

Voltage Chart Resistance Chart Top View of R-4B Chassis

Bottom View of R-4B Chassis

Schematic Diagram

22 22

28 29

36 37

Fold-out inside back cover

iii

SPECIFICATIONS

FREQUENCY COVERAGE:

ACCESSORY COVERAGE:

SELECTIVITY:

Covers 3.5 to 4.0 MHz, 7.0 to 7.5

MHz,

21.5 Ten accessory crystal sockets are

provided. Coverage of any ten additional 500 KHz ranges between

1.5 and 30

and 6.0

stalling accessory crystals.

The R-4B tunable passband filter provides four passbands. With the

selector set to .4, the bandwidth

is.4 KHz at 6 dB down and 2.6 KHz at 60 dB down. Set at 1.2, bandwidth is 1.2

and 4.8 KHz at 60 dB down. Set at 2.4, bandwidth is 2.4 KHz at

6 dB down and 8.2 KHz at 60 dB down. Set at 4.8 KHz, bandwidth

is 4.8 KHz at 6 dB down and 20 KHz at 60 dB down.

Selectivity switching is independ- ent of detector and AVC switching.

14.0 to 14.5

MHz,

and 28.5 to 29.0 MHz.

MHz

~xcept between 5.0

MHz)

can be added by in-

MHz,

KHz

at 6 dB down

21.0 to

INTERMEDIATE FREQUENCIES:

STABILITY:

SENSITIVITY:

MODES OF OPERATION:

SPURIOUS RESPONSES:

First is 5645 KHz with crystal

lattice filter, second is 50 KHz

with tunable LC filter.

After warm up, frequency will not

drift more than ± 100 Hertz. Line

voltage variation of ±10% will not

cause frequency shift in excess of

100 Hertz. 10 dB signal-pIus-noise to noise

ratio obtained on any amateur band with less than a .25 microvolt

signal on the antenna. SSB, CW, AM, RTTY Image rejection over 60 dB. I.F.

rejection over 60 dB on amateur

bands. Internal spurious response

less than the equivalent of a 1 microvolt antenna signal on all amateur bands.

SPECIFICATIONS

AVC:

INPUT IMPEDANCE:

OUTPUT IMPEDANCE:

AUDIO OUTPUT:

POWER CONSUMPTION:

SIZE:

CALIBRATION:

Amplified-delayed AVC with slow

(750 milliseconds) or fast (25

milliseconds) discharge, and less

than 100 microseconds charge time. A 60 dB change in R. F. input causes less than 3 dB change in audio output.

52 ohms nominal

4 ohms to speaker,

5000 ohms anti-vox.

0.5 watt at AVC threshold, 1.5

watts maximum.

60 watts, 120/240 volts A. C.,

50/60 Hertz.

5.5 inches high, 10.75 inches wide, 12.25 inches deep overall, weight 16 pounds.

Better than ~l KHz when calibrated at nearest 100 KHz calibration

point.

HUM

NOISE:

Greater than 60 dB below rated output.

TUBES AND SEMICONDUCTORS:

SPECIFICATIONS

Symbol

V2 V3

V4 V5 V6 V7 V8 V9 VlO

Q4 Q5 Q6 Q7

QlO

Type

6BZ6 68S6

l2BE6

12BA6

6EH5 6HS6

l2BA6 l2AX7A

2N3394 FET TIS34 2N3858 2N3877 2N3394 2N3394 2N3394 TIS-34 2N3394 2N3877

Function

R. F. Amplifier

First Mixer

Second mixer and crystal os- cillator

First I.F. Amplifier

Second I.F. Amplifier Symbol not used Audio output

Pre-Mixer

Noise Blanker Amplifier Noise shaper and pulse ampli- fier

Crystal Oscillator Variable Frequency Oscillator VFO Buffer Amplifier AVC Amplifier/detector AM Amplifier Beat Frequency Oscillator

Audio Amplifier Calibrator Oscillator Calibrator Trigger VFO Indicator Driver

DI D2 D3 D4,D5 D6 D7 D9 DlO DIl,D12 D13,D15 Dl4 Dl6 D17

ICI IC2

lN483A lN483A lN483A lN3194 IN3194 lN270 lN7l4 lN483A IN270 lN483A lN270 lN483A lN483A

923 923

Noise Pulse Detection Noise Pulse Detection Noise Blanking

B+

Rectifiers Bias Rectifier AM Detection.

Voltage Regulator Switching Diode

Product Detection

Steering Diode Switching Diode

Calibrator Supply Rectifier

Bias Clamping

Calibrator frequency divider

SECTION I General Description

1.1 INTRODUCTION

The Drake model R-4B is a double conversion superheterodyne re- ceiver, with preselector, designed for optimum reception of all

types of amateur radio communications. It gives complete cover-

age of the 80, 40, 20, and 15 meter bands, as well as the por-

tion of the 10 meter band from 28.5 ~rnz to 29.0 MHz. Additional

coverage between 1.5 and 30 MHz

possi ble using accessory crys- tals. A linear permeability-tuned solid state VFO and premixed injection from a crystal-controlled high frequency oscillator

give excellent stability on all bands. A crystal calibrator provides accurate frequency checkpoints at 25 KHz intervals

throughout the usable range of the receiver. Selectivity may be

varied with the passband tuner-filter which has four selectivity

positions. Noise blanking and AVC action are controllable from

the front panel.

1.2 AUXILIARY EQUIPMENT

Supplied - Shorted plug for insertion in Mute jack on rear deck

when external muting is not desired. Insertion of the shorted

plug is necessary for operation of Noise Blanker and Calibration circuits when external muting is not employed. Each R-4B is

shipped with this plug installed in the mute jack.

Required - 4 ohm speaker and/or 600 ohm headphones.

Available - MS-4 speaker, supplied with cable and connectors, housed in cabinet matching the R-4B.

SC-6,

SC-2,

SCC-l,

CPS-l,

noise

low

noise

low

VHF crystal

solid SC-2

state

and

converter

FET

converter

FET

calibrator

power

SCC-I.

supply

for

meters.

for

with FET.

SC-6,

for

meters.

T-4XBtransmitter, 200 watts PEP input power

on SSB and AM, 200 watts CWo

T-4Breciter, connects to R-4B and uses its

VFO, 200 watts PEP input on SSB, 200 watts input CWo

AC-4, solid state power supply for T-4 or T-4X

(can be housed in MS-4 cabinet).

.,,,.SECTION I

General Description

1.3 GENERAL ELECTRICAL CHARACTERISTICS

The R-4B operates from a nominal 115/230 volts, 50 to 60 Hertz,

single phase power source. If the receiver is to be operated from a 230 volt source, the power transformer primary winding

must be reconnected as indicated in the schematic diagram. Power consumption is 60 watts.

A resonant antenna having an impedance between 50 and 75 ohms

will give optimum performance. When the R-4B is used with a

transmitter, the transmitting antenna should be used for recep- tion, with the antenna changeover being accomplished with an

antenna relay. A high impedance output (5000 ohms)

jack on the rear of the R-4B chassis having voice control capabilities.

is provided at the ANTI-VOX

for use with transmitters

SECTION II Installation

2.1 UNPACKING Carefully remove the receiver from the shipping carton and ex-

amine it for evidence of damage. If any damage is discovered,

immediately notify the transportation company that delivered the

receiver.

rial, as the transportation company will want to examine them.

Keeping the carton and packing is recommended in any case, as

having these available makes shipping the receiver much easier should it ever be necessary to return it to the factory for service. Inspect the packing material before putting it away,

'to be sure you have not overlooked any accessory hardware. The

hardware consists of two studs, #10-24, 5/8 inches long, and

two small rubber feet.

Fill out and mail the warranty registration card.

Examine your R-4B,making sure all tubes and crystals are proper-

ly seated in their sockets. Check all switches and tuning con- trols for freedom of action.

sure to keep the shipping carton and packing mate-

2.2 LOCATING AND MOUNTING

The location of the R-4B is not critical, as long as care is

taken to allow for adequate air circulation. Avoid extremely

hot locations, such as adjacent to building heating outlets. It

~recommended that a minimum clearance of one inch be maintained at each side of the R-4B. Do not cover the top of the R-4B with books, paper, or pieces of equipment.

As supplied, your R-4B sits with its base parallel to the mount-

ing surface, and its front panel vertical to the mounting sur-

face. With the studs and rubber feet supplied, it is possible

to position the R-4B for either of two alternate viewing angles, as shown in Figure 2. To convert the R-4B to either option, the first step is to remove the bottom cover from the receiver. Remove the bottom row of three screws on each side of the re- ceiver, and the cover can be removed. Remove the rear feet, and snap the small rubber feet into the holes just inboard from the original rear feet. For option 1, put the bottom cover back on the receiver. For option 2, remove the front feet from the receiver, invert them, and remount them on the same screws. Then thread one of the accessory studs into each afthe remounted

front feet. Finally, mount the feet that were removed from the rear of the receiver on the stUdS, and put the bottom cover back

onto the receiver.

Ant

TR-4

~....---1

Po.er Cable

Speaker Cable

NOTE:

Thi••• itch must be In the TCVR position

for tronsce/vlnll and In the RCVR pOlltlon for leparate

'ecelve, u.e.

Mute Line

Receiver Ant enna Coble

AC-4/ MS-4 or RV-4

It .,

.. OIl

Lead to Speaker

NOTE: Connect in parallel.

(Braid to braid etc.)

R- 4B

FIG. I

USING THE R-4B WITH THE TR-4 TRANSCEIVER

VIEWING ANGLE OPTIONS

STANDARD

OPTION

SCREW MOUNTED REAR

FEET REMOVED

OPTION'# 2

-7-

r::1.//Io_--

STUDtf IOx24 x 5/8 LONG SUPPLIED WITH UNIT

INVERTED FRONT FEET

FEET REMOVED FROM REAR OF BASE

::.

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l&J Z

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