Elecraft KX1 User Manual
E L E C R A F T K X 1 T R A N S C E I V E R
12V
E L E C R A F T K X 1
37+S1 5 9
123RF
MENU
EDIT
BAND
SPEED
TUNE
LAMP
ON
OFF
1
DISP
POWER
RX
TX
RIT
CLR
2
TAP: 10 HZ / 100 HZ
\
KEY /
PADDLE
HOLD: 1 kHz
RF GAIN
0.5
FILTER
AF GAIN
ANT.
1.0
2.0
O W N E R’S M A N U A L
E LECRAFT KX1
Ultra-Portable
CW Transceiver
Owner’s Manual
Revision E, May 21, 2010
Copyright
2010 Elecraft, Inc.
All Rights Reserved
Elecraft www.elecraft.com P.O. Box 69 Aptos, CA 95001-0069 (831) 662-8345 Fax: (831) 662-0830
2 ELECRAFT
Table of Contents
INTRODUCTION .......................................................................................................................................................................................... 3
SPECIFICATIONS ........................................................................................................................................................................................ 5
PREPARATION FOR ASSEMBLY .............................................................................................................................................................. 6
ASSEMBLY - PART I ................................................................................................................................................................................. 14
ALIGNMENT AND TEST - PART I ............................................................................................................................................................ 27
ASSEMBLY – PART II ............................................................................................................................................................................... 30
ALIGNMENT AND TEST - PART II ........................................................................................................................................................... 43
ASSEMBLY - PART III ............................................................................................................................................................................... 48
ALIGNMENT AND TEST - PART III .......................................................................................................................................................... 58
FINAL ASSEMBLY .................................................................................................................................................................................... 60
OPERATION .............................................................................................................................................................................................. 62
KX1 OPTIONS ............................................................................................................................................................................................ 71
CIRCUIT DETAILS ..................................................................................................................................................................................... 72
PARTS LIST ............................................................................................................................................................................. APPENDIX A
SCHEMATIC ............................................................................................................................................................................ APPENDIX B
BLOCK DIAGRAM ................................................................................................................................................................... APPENDIX C
PHOTOGRAPHS ...................................................................................................................................................................... APPENDIX D
TROUBLESHOOTING ............................................................................................................................................................. APPENDIX E
PARTS PLACEMENT DRAWINGS ......................................................................................................................................... APPENDIX F
QUICK REFERENCE ............................................................................................................................................................... APPENDIX G
ELECRAFT 3
Introduction
The Elecraft KX1 is a compact, multi-band CW transceiver
optimized for backpacking and travel use. With internal battery,
internal automatic antenna tuner, log-book lamp, and plug-in keyer
paddle, it offers a high level of integration.
Unlike most transceivers, the KX1’s controls are located on the top
of the cabinet, and the keyer paddle attaches at the front. This “trailfriendly” format is ideal for hand-held or lap-top operation, e.g.
when sitting on the ground, using a camp chair, reclining, or even
standing. The KX1 is also at home on a table or desk, providing an
optimal display viewing angle without the need for a tilt stand. The
unique plug-in keyer paddle is both physically reversible for right- or
left-handed use.
The transceiver covers the full 40 and 20 meter bands, and optionally
80 and 30 meters. The VFO is based on a DDS (direct digital
synthesis) IC, so it can also tune well outside each band, covering
many popular SWL band segments. A variable bandwidth crystal
filter permits reception of SSB and AM as well as CW, facilitating
cross-mode contacts and broadcast reception.
The KX1’s internal six-cell battery pack can be changed in seconds
with the removal of two thumb screws. The battery provides 1 to 2
watts power output, which represents a good tradeoff between
battery life and communications efficiency. An external 12 V supply
increases output to about 4 watts. Low receive-mode current drain
(35 mA typ.) results in battery life of 20 hours or more. The lowbattery warning threshold can be adjusted to match the battery type
used.
The KX1 uses a 3-digit LED display that is physically rugged and
extremely efficient. It requires just 1 to 2 milliamps total current in
moderate lighting conditions, and about 10 mA at its brightest setting.
The operator can optionally configure the display to turn off 5 to 60
seconds after any front-panel control has been used. Operation without
the display is possible if the CW feedback feature is turned on (audio
Morse code). This provides audible announcement for the VFO dial,
menu text, and all controls.
Additional operating features include instant band selection, nine
frequency memories, three VFO tuning rates, receive incremental tuning
(RIT), USB/LSB receive on all bands, and an S-meter display mode.
The built-in keyer offers Iambic modes A and B and two message
buffers. In an emergency, two of the front panel switches can be
configured for use as a manual key or keyer paddle.
Despite its compact size and many built-in accessories, the KX1 is easy
to build. The basic unit consists of a single printed circuit board, with no
surface mount components to install (the three surface mount parts used
are pre-installed). Assembly and test are completed in phases to simplify
any needed troubleshooting, and only a few alignment steps are
required.
We’d like to thank you for choosing the KX1 transceiver, and hope it
meets your expectations for ultra-lightweight portable operation.
Wayne Burdick, N6KR
Eric Swartz, WA6HHQ
4 ELECRAFT
Customer Service Information
Elecraft's 1-Year Limited Warranty
Technical Assistance
If you have difficulty with kit construction, operation, or
troubleshooting, we’re here to help. You may be able to save time by
first consulting our web site, www.elecraft.com
question on the Elecraft e-mail forum, elecraft@mailman.qth.net
, or by posting your
.
Telephone assistance is available from 9 A.M. to 5 P.M. Pacific time
(weekdays only) at 831-662-8345. You can also send e-mail to
support@elecraft.com
. Please use e-mail, rather than call, when
possible since this gives us a written record of the details of your
problem.
Repair Service
If necessary, you may return your completed kit to us for repair.
Contact Elecraft before mailing your kit to obtain the repair
shipping address, as well as information on repair fees. (Kits that
have been soldered using acid core solder, water-soluble flux solder,
or other corrosive or conductive fluxes or solvents cannot be
accepted for repair–see Warranty.)
The following information should be provided to expedite repair:
your name, address, and phone number; your e-mail address (if
applicable); and a complete description of the problem.
Shipping: First, seal the unit in a plastic bag to protect the finish
from dust and abrasion. Use a sturdy packing carton with 3" or more
of foam or shredded paper on all sides. Seal the package with
reinforced tape. (Neither Elecraft nor the carrier will accept liability
for damage due to improper packaging.) Cover the "to" address label
with clear tape.
This warranty is effective as of the date of first consumer purchase (or if shipped from
factory, date product is shipped to customer). It covers both our kits and fully
assembled products. For kits, before requesting warranty service, you should fully
complete the assembly, carefully following all instructions in the manual.
Who is covered: This warranty covers the original owner of the Elecraft product as
disclosed to Elecraft at the time of order. Elecraft products transferred by the
purchaser to a third party, either by sale, gift or other method, who is not disclosed to
Elecraft at the time of original order, are not covered by this warranty. If the Elecraft
product is being bought indirectly for a third party, the third party's name and address
must be provided to Elecraft at time of order to insure warranty coverage
What is covered:
defective or missing parts free of charge (post-paid). We will also correct any
malfunction to kits or assembled units caused by defective parts and materials.
Purchaser pays inbound shipping to Elecraft for warranty repair, Elecraft will pay
shipping to return the repaired equipment to you by UPS ground service or equivalent
to the continental USA and Canada. Alaska, Hawaii and outside U.S. and Canada
actual return shipping cost paid by owner
What is not covered:
errors. It also does not cover misalignment; repair of damage caused by misuse,
negligence, or builder modifications; or any performance malfunctions involving nonElecraft accessory equipment. The use of acid-core solder, water-soluble flux solder,
or any corrosive or conductive flux or solvent will void this warranty in its entirety.
Also not covered is reimbursement for loss of use, inconvenience, customer assembly
or alignment time, or cost of unauthorized service
Limitation of incidental or consequential damages:
extend to non-Elecraft equipment or components used in conjunction with our
products. Any such repair or replacement is the responsibility of the customer.
Elecraft will not be liable for any special, indirect, incidental or consequential
damages, including but not limited to any loss of business or
During the first year after date of purchase, Elecraft will replace
.
This warranty does not cover correction of kit assembly
.
This warranty does not
profits.
.
ELECRAFT 5
Specifications
General
Size (H x W x D)
Cabinet 1.2 x 5.3 x 3.0" (3 x 13.5 x 8 cm)
Overall 1.4 x 5.8 x 3.0" (3.5 x 15 x 8 cm)
Weight 9 oz. (0.25 kg), excluding options
Supply voltage 7-14 V (8 V min. recommended)
Current drain
Receive 35 mA typ., 40 mA max (headphones,
LED display timed out, 30-m or
30/80-m option installed)
Transmit 300-700 mA (varies with supply
voltage and power output setting)
1
Bands covered (MHz)
Receive 5.0-9.5 and 12.0-16.5 MHz
Transmit 7.000 to 7.300, and 14.000 to 4.350
Frequency control DDS with 50 MHz crystal reference
VFO drift < 50 Hz per hour after 5-minute
Display 3-digit LED w/bargraph mode;
MHz; spurious content at 3 to 4 w, 2
harmonic -40 dB typ. with LPF
adjustment (see page 59)
warm-up at 25° C
audio CW feedback on keypress
Transmitter
Max. power output (approx.)
9 V supply 1.5-2 W
12 V supply 3-4 W
Spurious content -40 dB @ 3 to 4 W
Load tolerance 2:1 or better SWR recommended
Sidetone pitch 500-650 Hz in 10 Hz steps
Keyer 8-50 WPM; Iambic modes A and B;
2 message buffers; auto-repeat
Receiver
Sensitivity Approx. 0.2 µV for 10 dB (S+N)/N
nd
I.F. 4.915 MHz, single conversion
Selectivity 3-pole variable-bandwidth crystal
filter, approx. 300-2000 Hz
Audio output 0.1 watt into 8-ohm load;
stereo plug required
1
KXB30 option adds 8.0-12.5 MHz receive and 10.1-10.15 MHz transmit.
The KXB3080 option covers the same range as the KXB30 and adds 1.5-5.5
MHz receive and 3.5-4.0 MHz transmit. Adding either module also greatly
improves sensitivity in the 49-meter band (5.9-6.4 MHz).
6 ELECRAFT
Preparation for Assembly
Overview of the KX1
The KX1 chassis consists of a top and bottom cover (Figure 1). All
components, including controls and connectors, are mounted on a
single printed circuit board (PCB). Only three surface-mount
components are required, and these are pre-mounted to the board.
The top cover is also the front panel. The controls face upward for
convenient operation. The printed circuit board mounts directly behind
the front panel.
The automatic antenna tuner option (KXAT1) plugs into the bottom of
the main PC board at J6, J7 and J8. The optional keyer paddle
(KXPD1) plugs into the Keyer/Paddle jack, J3, at the front edge of the
top cover.
The bottom cover is held in place by two thumbscrews. Two three-cell
AA battery sockets are attached to the bottom cover and are wired in
series to form a six-cell pack. The battery voltage is 7.2 or 9 V
depending on the battery type.
Appendix D provides close-up views of the top and bottom of the
assembled PC board.
Figure 1. KX1 Overview.
ELECRAFT 7
Unpacking and Inventory
Preventing Electro-Static Discharge Damage
Problems caused by Electro-Static Discharge (ESD) may be very
difficult to troubleshoot because damaged components may still
operate somewhat rather than fail completely. We strongly recommend
you take the following anti-static precautions (listed in order of
importance) to avoid trouble:
Leave ESD-sensitive parts in their anti-static packaging until
you install them. The packaging may be a special plastic bag
or the component’s leads may be inserted in conductive foam.
Parts which are especially ESD-sensitive are identified in the
parts list and in the assembly procedures.
Wear a conductive wrist strap with a series 1 megohm
resistor. If you do not have a wrist strap, touch a ground
briefly before touching any sensitive parts to discharge your
body. Do this frequently while you are working. You can
collect a destructive static charge on your body just sitting at
the work bench. DO NOT attach a ground directly to
yourself as this poses a serious shock hazard.
Make sure your soldering iron is ESD-safe and has a
grounded tip
Use a grounded anti-static mat on your work bench.
Inventory
We recommend that you do a complete inventory, using the parts lists
in Appendix A.
i
DO NOT HANDLE PARTS OR CIRCUIT BOARDS
WITHOUT ANTI-STATIC PROTECTION (see Preventing
Electro-Static Discharge Damage above). Do not remove the black
foam from the leads of any parts. This foam is further protection
against static damage.
Many components are inside small envelopes and bags. Open them
one at a time, and return all of the parts to the envelope before opening
another. Be careful to avoid mixing parts and putting them in the
wrong bags or envelopes.
8 ELECRAFT
Y
V
X
X
Identifying Common Resistors and RF Chokes
The color bands that indicate the value of each resistor are shown in
the text to help you identify each part. However, it's helpful to
familiarize yourself with the color code. The color-code chart (see
Figure 2) shows how to read the four color bands on 5% resistors. For
example, a 1,500 ohm (1.5 k) 5% resistor has color bands BROWN,
GREEN, RED and GOLD.
1% resistors are similar, but use five bands: three significant digits, a
multiplier instead of a gold or silver tolerance band, and a fifth and to
indicate the tolerance. Since the bands usually fill the length of the
resistor body, the fifth band is wider to indicate that the value should
be read starting at the other end.
For example, the first four bands on a 1.50 k, 1% resistor are
BROWN, GREEN, BLACK, BROWN. The multiplier value is 1
rather than 2 in this case because of the third significant digit.
If in doubt about a resistor’s value, use a DMM. It may be difficult to
see the colors on some resistors. Do not be concerned with minor
deviations of your DMM reading from the expected value. Typical
errors on most DMMs and the tolerances of the resistors normally
produce readings that are slightly different from the value indicated by
the color bands.
RF chokes and other small molded inductors look very much like short
resistors. They have color bands that represent the same numeric
values as resistors but because the inductors are short, it may not be
obvious how to read them. In general the multiplier or tolerance bands
are closer to the end than the first digit, just the opposite of the way a
resistor. On small inductors the color bands may be centered on the
body.
If you sort out the inductors before starting assembly, you will be able
to positively identify each inductor from the color bands listed in the
Parts List.
USED ON 1%
RESISTORS
FIRST DIGIT
SECOND DIGIT
MULTIPLIER
COLOR
Black
Brown
Red
Orange
ellow
Green
Blue
iolet
Gray
White
Silver
Gold
DIGIT
0
1
2
3
4
5
6
7
8
9
-
-
(SEE TEXT)
TOLERANCE:
GOLD = 5%
SILVER = 10%
MULTIPLIER
X 1
X 10
X 100
X 10K
X 10K
100K
X 1M
-
-
-
0.01
X 0.1
Figure 2. Resistor Color Codes.
ELECRAFT 9
Identifying Resistor Packs
Resistor packs combine a number of resistors in one component with
multiple leads. They may be in-line packages with 6 or 10 leads in a
row or they may be in 16-pin dual in-line pin (DIP) packages similar
to many integrated circuits.
Like integrated circuits, pin 1 of each component is identified by a dot
near it. Some resistor packs are symmetrical. That is, they can be
installed either way. However, some are not. ALWAYS follow the
instructions and orient the resistor pack exactly described in the
procedure.
The value of the resistor pack is indicated in the last three digits shown
on the package. The numbering scheme is similar to capacitors. The
first two digits indicate the first and second most significant digits and
the third digit is a multiplier. For example, “...391” indicates 390 ohms
and “...104” indicates 100,000 ohms (100K).
Identifying Capacitors
Capacitors are identified by their value and the spacing of their leads.
Small-value fixed capacitors are usually marked with one, two, or
three digits and no decimal point. If one or two digits are used, that is
the value in picofarads (pF). If there are three digits, the third digit is a
multiplier. For example, a capacitor marked "151" would be 150 pF
(15 with a multiplier of 10
"102" would be 1000 pF (or .001 µF). Exceptions are described
specifically in the text and parts list.
1
). Similarly, "330" would be 33 pF, and
Fixed capacitors with values of 1000 pF or higher often use a decimal
point in the value, such as .001, .047, or 2.2. This is the value in
microfarads (µF). (1 µF is equal to 1,000,000 pF.)
The lead spacing is noted in the Parts Lists for most capacitors. If two
different types of capacitors have the same lead spacing will indicate
which one to use. When lead spacing is important, both the value and
the lead spacing is shown in the assembly procedure. For example,
“LS 0.1” means that the lead spacing is 0.1 inch (2.5 mm).
Identifying Toroid Cores
Several toroidal inductors are used in the KX1. It is important to use
the correct type of core. This can be determined from the color and
size. Two types of cores are used in the KX1: Iron powder cores and
ferrite cores. If you mix them up, your KX1 will not operate properly.
The iron powder cores used are type T37-6. The T identifies an iron-
powder core. The number following the T specifies the outside
diameter in hundredths of an inch, in this case 0.37 inches (9.4 mm).
The suffix (-6) refers to a specific mix of iron powder. You cannot tell
what mix of iron power is used by looking at the core, so they are
painted with specific colors. The -6 cores are painted yellow.
Ferrite cores are indicated in the parts list by the letters FT in the part
number. The KX1 uses FT37-6 cores. Like the iron powder cores, the
37 refers to the outside diameter. The -46 identifies the type of ferrite
used. These cores are not painted. They are dark grey.
10 ELECRAFT
Tools
You will need the following tools to build this kit:
Fine-tip temperature-controlled ESD-safe soldering station
with 700 to 800F tip (370-430C). Recommend a spade tip
approx. 0.05” (1.3 mm) wide. Do not use a high-wattage iron
or soldering gun since this can damage pads, traces, or the
parts themselves.
IC-grade, small-diameter (.031”) solder (Kester #44 or
equivalent).
i
DO NOT use acid-core solder, water-soluble flux solder,
additional flux or solvents of any kind. Use of any of these will
void your warranty.
Desoldering tools and supplies are invaluable if you make any
modifications or need to do any repairs. Narrow solder wick or
a good vacuum desoldering tool such as the Soldapullt®
model DS017LS are recommended. See Soldering and
Desoldering, on page 11 for more information.
Screwdrivers: A small #2 Phillips, a small flat-blade for
slotted screws and a very small flat-blade (about 0.1 in or 2.5
mm wide) with an insulated handle to adjust the trimmer caps.
We strongly recommend that you use a conductive wrist strap and
anti-static mat during assembly. These items are available at very low
cost from Jameco, Mouser, and other electronics suppliers.
Refer to www.elecraft.com for tool sources and solder
recommendations.
Needle-nose pliers.
Small-point diagonal cutters. Flush-cutting type is required
(Xcelite MS54-5J or equivalent).
Digital Multimeter (DMM) for voltage checks and confirming
resistor values. A DMM with capacitance measurement
capability is desirable, but not required.
50-ohm dummy load capable of handling 5 watts, minimum.
Magnifying glass or visor.
ELECRAFT 11
Soldering and Desoldering
Solder joints should be clean and shiny. If a joint appears dull or has
i
Use adequate ventilation when soldering; avoid
inhaling smoke or fumes. Always wash your hands after
handling solder, as lead residue is highly toxic.
Solder Recommendations
We recommend small-diameter (.02 to .03") rosin-core solder, similar
to Kester type 44. Solder with 2% silver is used by some builders and
will work equally well.
If you use a minimum of solder, there will be no need to clean PC
boards. The use of acid-core solder, water-soluble flux solder, or any
corrosive or conductive flux or solvent is likely to damage components
and/or PC boards.
fine cracks, it is probably cold. Cold solder joints should be cleaned
and re-soldered. First, use solder wick (desoldering braid) to remove
the old solder. Then apply fresh solder. If you have many cold solder
joints, it probably indicates that your soldering iron temperature is too
low, or that the tip or solder itself is defective.
New soldering iron tips must be tinned before they’re used. Allow the
iron to warm up completely, then apply solder and allow it to coat the
entire tip. After a few minutes, wipe off the excess solder. Use a
sponge for wiping the iron tip, and clean the sponge often.
Soldering
When applying solder, use the minimum amount required to surround
the component lead and make good contact with its printed-circuit pad.
You don't need a "fillet" (build-up) of solder.
To provide a good connection, the solder must flow onto both the
component lead and its PC board pad. To ensure that both will be
heated at the same time, the tip of the iron should contact both the
component lead and the PC board pad before solder is applied.
12 ELECRAFT
Desoldering
The printed circuit boards used in the kit are double-sided, meaning
that they have circuitry on both sides. The component mounting holes
are plated-through to complete electrical connections between the two
sides.
Removing components from double-sided boards can be difficult,
since you must get all of the solder back out of the hole before a lead
can be removed. To do this, you'll need solder wick (desoldering
braid) and/or a vacuum desoldering tool. It also takes some practice. A
number of suggestions are provided below.
The best strategy for avoiding de-soldering is to place all
components properly the first time. Double-check values and
orientations, and avoid damaging parts via ESD.
When removing components:
Don't pull a lead or pin out of a hole unless the solder has been
removed, or you are applying heat. Otherwise, you can literally
pull out the plating on the plated-through hole.
Limit soldering iron contact to a few seconds at a time.
Use small-size solder-wick, about 0.1" or 2.5 mm wide. Use the
wick on both the top and bottom pads when possible. This helps
get all of the solder out of the hole.
If you use a vacuum desoldering tool (solder sucker), use a large
unit. Small solder suckers are not very effective.
The safest way to remove ICs and other components with more
than 3 leads is to clip all of the pins at the body of the device first,
then remove all of the pins individually. You may damage pads
and traces by trying to remove such components intact.
Invest in a PC board vice with a heavy base if possible. This
makes parts removal easier because it frees up both hands.
If in doubt about a particular repair, ask for advice from Elecraft or
from someone else with PCB repair experience.
ELECRAFT 13
Assembly Notes
Each step in the assembly process is accompanied by a check-box:
As you may have noticed already, the symbol below is used to alert
you to important information:
i
Do not skip any steps. You may adversely affect both the
performance and appearance of the kit by using the wrong
assembly order.
Installing Parts
Follow the instructions carefully about the position of parts. Many
parts must be positioned exactly as instructed or they may strike the
case or other components when the KX1 is assembled.
The value and corresponding color codes are shown for all resistors
and inductors that may have them. In some cases the value may be
stamped on the component instead of the color code.
IC Sockets
Only one integrated circuit is mounted in a socket. Do not use a
different type of socket. The one supplied is a low-profile socket that
provides just enough room for the case to fit together.
Do not use sockets on any ICs other than the one provided. Mount the
other ICs directly on the board as instructed. Sockets will not allow the
cover to close. Also sockets in RF may cause improper circuit
operation due to increased lead inductance and capacitance.
Before beginning assembly, you should review the photographs in
Appendix D to see what the completed PC boards look like. You'll
also find front and back views of each PC board in the Parts Placement
Drawings, Appendix F.
14 ELECRAFT
Assembly - Part I
In Part I, the control, display, and audio stages will be assembled and
tested. Later sections cover receiver (Part II) and transmitter (Part III)
assembly and test.
i
BEFORE YOU START:
1. WEAR A GROUNDED WRIST STRAP or ground
yourself briefly before touching components. You can
discharge static by frequently touching an unpainted,
grounded metal surface.
2. WEAR EYE PROTECTION before trimming any leads.
3. WASH YOUR HANDS after handling solder. Solder is a
toxic substance.
4. PROVIDE VENTILATION and avoid inhaling the fumes
produced by soldering.
If you haven’t done so already, open the bag of components
labeled KX1 MAIN BAG and sort the parts into groups. Many of the
components will be in small paper envelopes. Do not mingle the
contents of one envelope with another. As you are instructed to locate
particular components, use the photographs in the KX1 PCB parts list
in Appendix A to help identify them.
i
The components pre-installed on the circuit board are
extremely static-sensitive. Wear a wrist strap or ground yourself
before handling the board.
Position the circuit board on your bench so that KX1 is visible in
the upper left corner. This is the side of the board that will be directly
under the front panel when the transceiver is completed. This side will
be referred to the as the top face of the board throughout the assembly
procedure. Components will be installed on both sides of the board.
Turn the circuit board over so the bottom is facing up and orient
it so the outline for J1 is in the upper right corner. Find the outline for
resistor R8 next to the outline for J1.
ELECRAFT 15
A
Bend the leads of resistor R8, 6.8k (blu-gry-red), 1/4 watt, at
right angles close to the body. Insert the leads in the solder pad holes,
and bend them out on a 45-degree angle on the opposite side of the
board to hold the resistor in place.
i
Components MUST be tight against the board or the case
may not close properly during final assembly. This is especially
true of components on the bottom of the board where there is very
little clearance between the board and the battery packs.
Check the position of the resistor to ensure it is centered in the
printed outline and flush against the board as shown in Figure 3.
Solder and trim the leads.
ENSURE MARKINGS AGREE WITH
INSTRUCTIONS IN TEXT
BODY OF PART
GAINST THE BOARD
SOLDER & TRIM LEADS FLUSH
Figure 3. Installing Fixed Resistors.
Bend the leads of resistor R28, 1.8k (brn-gry-red), 1/4 watt, to fit
in the holes indicated on the board. Note that the leads should NOT be
bent close to the body of the resistor like you did for R8. Fit the leads
so the body of the resistor sits against the board within the outline,
then bend them outward at about a 45 degree angle to hold the resistor
in place.
Solder the leads to R28 and trim them flush with the board.
i
From this point forward, instructions to “install” a
component mean to position it within its outline against the board,
solder, and trim the leads flush on the opposite side.
Locate the two 200 ohm (red-blk-brn)1/8 watt fixed resistors, R6
and R7. They are about half the size of the 1/4 watt resistors you just
installed.
Install the 1/8 watt resistors in the spaces shown just to the left of
R8 near the top of the board:
_ R6, 200 ohms (red-blk-brn), 1/8 watt.
_ R7, 200 ohms (red-blk-brn), 1/8 watt.
Locate the printed outline for R28 on the back of the board. It is
about 3/4” (2 cm) down from the top edge near the center.
i
Components may be soldered one at a time or in groups.
Leads can be trimmed either before or after soldering.
16 ELECRAFT
i
Save the longer clipped component leads. Several of them
will be needed for grounding wires and a jumper.
Install the following 1/4 watt resistors on the bottom side of the
board. Their locations are in the lower right quadrant of the board
when it is oriented the so outline for J1 is in the upper right corner.
_ R16, 1k (brn-blk-red).
_ R17 ,1k (brn-blk-red).
_ R22, 300 ohms (org-blk-brn).
_ R23, 470 ohms (yel-vio-brn).
Turn the board over (top face up) and orient it so that the KX1
lettering is in the upper left corner and the notch is on the lower edge.
Install the following 1/4 watt resistors about 3/4” (2 cm) to the left
of the notch and about 3/4” (2 cm) up from the lower edge of the
board:
_ R12, 6.8k (blu-gry-red).
_ R13, 22k (red-red-org).
Locate resistor pack RP5, 100 k ohm (104). RP5 is a ten-pin inline package whose number on the side ends in “104” (see Figure 4).
If you are in doubt about the value, use your DMM to verify that the
resistance between adjacent pins is 100k ohms. Note the dot at one end
indicating pin 1.
Figure 4. Installing Resistor Packs.
Find the outline for RP5 on the top of the circuit board. With the
board face up so that KX1 is in the upper left corner, the outline for
RP5 is just to the left and above the notch at the center of the lower
edge of the board.
ELECRAFT 17
FLARED
Insert RP5 with Pin 1 of the pack in the round solder pad. The
round pad is farthest from the edge of the board.
i
Be careful to orient the resistor packs so the dot next to
Pin 1 on the pack is at the round solder pad on the board. Once
soldered in place, it is almost impossible to remove the pack
without destroying it.
Wet your soldering iron with a small amount of solder, and touch
it to one of the pins to tack-solder it in place.
Check the position of RP5 to verify that the pins at both ends are
inserted as far as they will go into the board as shown in Figure 4, then
solder and trim all ten leads.
Follow the same procedure to install six-pin resistor pack RP2, 1K
(102) above and to the left of RP5. Pin 1 goes at the top pointing
toward the printed outline for C51.
Install ten-pin resistor pack RP4, 10k (103) below U2 in the top
left quadrant of the board. Pin 1 goes to the left, pointing toward the
outline for RP3.
Install ten-pin resistor pack RP3, 10k (103) to the left of RP4. Pin
1 of RP3 is at the top, nearest the end of RP4.
Locate resistor pack RP1, 390 ohms (391). RP1 is in a 16-pin DIP
package that looks much like an integrated circuit. The resistance
elements run across the package (e.g. pin 1 connects to 9 through 390
ohms).
Test fit RP1 between RP2 and RP3 and just below the outline for
DS1 on the circuit board. It is normal for the pins of a DIP package to
be slightly flared so they do not easily fit into the solder pad holes. If
necessary, place RP1 so that an entire row of pins is against a smooth
surface and straighten the pins as shown in
Figure 5.
PRESS AND
ROCK TO
STRAIGHTEN
Figure 5. Straightening IC Pins.
Place RP1 on the circuit board with pin 1, indicated by a dot on
top of RP1, in the round solder pad. Be sure it is seated all the way so
the shoulders on the pins are against the board. Solder and trim all 16
pins.
STRAIGHT
18 ELECRAFT
Turn the board face up so KX1 is in the upper left corner. Locate
the printed outlines for diodes D2 and D3 near the center of the left
edge of the board.
Locate diodes D2 and D3 (1N5817). Note that there is a band on
one end of the diode body.
i
All diodes MUST be installed with the banded end of the
diode over the band on the circuit board.
Install the following diodes:
_ D2 (1N5817)
_ D3 (1N5817)
With the board face up (KX1 in the upper left corner) position the
28-pin socket in the space provided for U1 in the lower left quadrant
of the board. The outline has (SOCKET) inside of it.
i
DO NOT TRIM the 28-pin socket pins before or after
soldering. These pins are hollow and form the lower part of the
socket for the IC pins.
i
Do not substitute a different socket for the one provided.
The very low profile of the supplied socket is required for the case
to fit together during final assembly.
Orient the socket so the notch at one end is toward the left edge of
the board, aligned with the notch in the printed outline.
Hold the socket against the circuit board and tack-solder pins at
opposite corners of the socket.
i
Do not overheat the socket pins. Too much heat will melt
the plastic socket. Use only enough solder to make a good joint.
Check to ensure that the socket is pressed against the circuit board
at both ends. If necessary, reheat the pins at each end and press down
on the socket so it rests directly against the board.
Solder all 28 pins. Double-check your work and inspect each pin.
Use a magnifier if necessary. If a pin is missed or poorly soldered, it
may make contact during initial testing, but become intermittent later.
Such intermittents can be very difficult to troubleshoot. Remember;
do not trim the socket pins!
ELECRAFT 19
Turn the board face down so the printed outline for power
connector jack J1 is in the upper right corner.
Locate the printed outline for C39 to the left of the outline for J1
on the board.
Test fit a .1 µF (104) capacitor in the solder pad holes for C39.
Position the capacitor so that about 1/16” (1 mm) of lead shows above
the surface of the board. If necessary, gently straighten the leads using
long nosed pliers. Do not tug on the leads. Squeeze and bend them
with your pliers as needed.
Solder and trim the C39’s leads.
Bend C39 down against the board as shown in Figure 6.
Figure 6. Positioning C39 Against the PCB.
Test fit a .1 µF (104) capacitor in the solder pad holes for C31.
Use a ruler to verify that the top of the capacitor is no more than 5/16”
(7.9 mm) above the board. Normally these capacitors will be well
below that height limit but, if necessary, gently straighten the leads
using long nosed pliers so it will sit closer to the board and meet the
height requirement. While forming the leads, do not tug on them.
Squeeze and bend the leads with your pliers to straighten them.
Slight chipping of the epoxy around the leads will not harm the
capacitor.
Figure 7. Installing Fixed Capacitors.
Solder and trim the leads on capacitor C31.
Locate the outline for capacitor C31 along the top edge of the
board just to the left of the outline for J1.
20 ELECRAFT
Following the same procedure, install capacitor C30, .01 µF (103)
next to C31.
Turn the board top face up so that KX1 is in the upper left corner.
In the following steps you will install several capacitors on the top of
side of the board. Be sure that the top of no capacitor is more than
5/16” (7.9 mm) above the board. Be especially careful of the larger
electrolytic capacitors (see Figure 8). Use a ruler as needed to check
the height.
Figure 8. Maximum Height of Capacitors on Top of Board.
Install capacitor C6, .01 µF (103) directly above diode D3 on the
left edge of the board.
Install capacitor C37, .01 µF (103) between D2 and resistor pack
RP3.
Install capacitor C5, .1 µF (104) below the socket for U1 near the
bottom edge of the board.
Install the following capacitors between the socket for U1 and the
bottom edge of the board:
_ C25, 27 pF (270)
_ C24, 27 pF (270)
Install the following capacitors to the right of resistor pack RP5:
_ C32, .01 µF (103)
_ C33, .01 µF (103)
Install capacitor C55, .01 µF (103) on the bottom edge of the
board about 1-1/4” (2 cm) to the right of resistor pack RP5.
Locate electrolytic capacitor C38 (10 µF, 35 v) and inspect the
leads. One lead should be shorter than the other. The capacitor body
will have a stripe and a minus sign (—) above the shorter lead.
Locate the printed outline for C38 to the left of RP3 on the top
face of the circuit board. Note that there are two solder pads for the
capacitor leads: one is round and one is square. A plus (+) symbol is
printed next to the square pad.
Install capacitor C12, .1 µF (104) between D2 and the socket
for U1.
ELECRAFT 21
Insert electrolytic capacitor C38 (10 µF, 35 v) with the longer lead
passing through the square solder pad with the (+) symbol next to it
and the shorter lead through the round pad. Bend the leads to hold the
capacitor in place against the board.
Be sure that the capacitor is tight against the board and solder the
leads. Use a ruler to verify that the top of the capacitor is no more than
5/16” (7.9 mm) above the board (see Figure 8). After soldering, trim
the leads flush with the bottom of the board.
i
All electrolytic capacitors MUST be installed with their
leads oriented to observe the polarity markings as described
above.
Install electrolytic capacitor C10 (10 µF, 35 v) below resistor R13
at the bottom edge of the board. Observe the proper polarity as you
did for C38 above, and be sure the capacitor is no higher than
5/16” (7.9 mm) above the board.
Turn the board over so the bottom face is up and the outline for J1
is in the upper right corner.
Turn the board over so the top face is up and test-fit the lowprofile crystal in the space provided for X1 near the bottom edge
below the socket for U1. The crystal may be installed either way.
Note: The holes in the solder pads for X1 may be larger than necessary
to fit the leads. This is normal. It is to accommodate different styles of
leads on the crystals supplied with some kits.
i
Do NOT use more solder than necessary on the leads for
X1. Too much solder will wick through the holes and may cause a
short to the case of X1 underneath the crystal. The short is
impossible to see or correct without removing the crystal.
Spread X1’s leads as necessary to hold the crystal against the
board and solder one lead. Do not hold your iron on the lead more
than 2 or 3 seconds, maximum. Too much heat will ruin the
crystal.
Check to ensure that X1 is sitting directly against the board. If
necessary, reheat the soldered lead while pressing down on the crystal.
Solder the second lead to X1 and trim the leads flush.
Install electrolytic capacitor C7 (220 µF, 25 v) at the center of the
board near resistor R28. Be sure to observe the proper polarity as
you did above. Save one of the clipped leads to use in the following
steps.
22 ELECRAFT
Use a discarded component lead to ground the case of the crystal
as follows:
_ Solder one end of the lead in the ground hole near the edge of
the board to on the left side of the crystal.
_ Tin the top of the crystal nearest the lead with a small amount
of solder. Keep the soldering time to 3 seconds or less to
avoid overheating the crystal. Allow the crystal to cool if you
need to apply heat more than once. It often helps to tin the
case more quickly if you lightly scrape the metal with a knife
or a screwdriver blade first.
_ Bend the ground lead so it lies flat against the top of the
crystal where it is tinned and solder it to the top of the metal
case.
Install white LED D1 as follows:
_
Figure 9. Installing LED D1.
Turn the bottom face up with the outline for J1 in the upper right
corner.
Position J1 (DC power connector) on the board so the three tabs
on the bottom of the jack fit through the slotted solder pads.
_ Locate the flat side on D1’s flange.
_ Position D1 over the outline in the lower left corner of the
board with the flat side of the flange toward the corner of the
board.
_ Bend the leads so that when they are inserted through the
solder pads, D1 rests against the board as shown in Figure 9.
Note: This LED is provided to illuminate your note pad or log
while operating in the dark. The slight downward angle will
help direct the light down onto the table top.
_ Check to ensure that the flat side of the flange is toward the
corner of the board. D1 will not work if it is installed
backwards.
_ Solder and trim both leads.
Solder one of the tabs and then check the position of the jack. It
must be centered within the printed outline on the board with the
connector opening parallel with the edge of the board. Be sure the jack
is resting directly against the board. There must be no gap between
jack and the board. If necessary, reheat the soldered tab and adjust the
position of the jack.
When you are satisfied with the position of the jack, solder the
remaining two tabs, then recheck the first tab be sure it is properly
soldered.
ELECRAFT 23
Test-fit two-pin plug P1 directly below J1. Orient P1 so the
locking ramp that sticks up alongside the pins is on the side farthest
from J1 as shown on the printed outline on the board.
Place the shell for the mating jack over the pins of P1 to protect
your fingers and, while holding P1 directly against the board, solder
one of P1’s pins. Check the following. If necessary, reheat the
soldered pin and adjust P1.
_ P1 is oriented so the locking ramp is on the side
farthest from J1.
_ P1 is sitting vertically and resting flat against the board.
Solder the second pin of P1 to the board, then touch up the tacksoldered connection as needed to form a good joint.
i
If J3 is not aligned correctly as described in the next step,
the front cover will not fit during final assembly.
Install J3 at the center of the bottom edge of the board using the
same procedure to ensure it is square, inside the silk-screened outline
and flat against the board. Be certain you mount the jack on the
BOTTOM face of the board within the printed outline.
Turn the board over so the top face is up with KX1 in the upper
left corner.
i
Do not install caps on pushbutton switches S3, S4, and S5
until instructed to do so later in the assembly process. It is very
easy to damage the caps while soldering adjacent parts.
Position switch S5 on the board between RP2 and RP5. it may be
oriented either way that places the four pins in the solder pad holes.
With all four pins in the solder pad holes, press down on S5 until the
plastic bumps on the bottom of the switch body are touching the
board. Use a magnifier if necessary to be certain that the bumps on the
bottom of the switch are against the board. Each of the four pins
should stick out through the solder pads on the bottom of the board
about 3/32” (2.4 mm).
When you are satisfied that the switch is firmly against the board,
solder and trim all four terminals.
Install pushbutton switches S4 and S3 next to S5 using the same
procedure.
24 ELECRAFT
Test fit slide switch S2 along the edge of the board next to
electrolytic capacitor C10. The switch can be oriented either way
around. Note that it rests on shoulders on the three terminals that
determine its height above the board.
Hold S2 vertical and against the shoulders on the tabs with your
finger on the slide, and tack-solder the center pin to hold it in place.
Inspect the switch to be sure it is perfectly vertical and not tipped
to either side. If necessary, reheat the pin and adjust the switch’s
position.
When you are satisfied that the switch is perfectly straight, solder
the two end pins. Resolder the center pin last as needed to create a
good joint.
Use the same procedure to install slide switch S1 to the left of
crystal X1. S1 also may be mounted oriented either way.
i
Voltage regulators U8 and U9 are installed in the following
steps. These devices look very similar. Double check the markings
on each device to be sure you have the correct one before soldering
it in place.
Install U8 (78L05) next to pushbutton switch S5 as follows:
_ Align the flat side of the device as shown by the printed
outline (see Figure 10).
_ Insert the device into the solder pad holes until the top of the
device is less than 5/16” (7.9 mm) above the board. Use a
ruler to confirm the height. If necessary, remove the device
and form the center lead to allow it to sit close enough to the
board.
_ Solder and trim all three leads.
R
ROUNDED
BACK
FLATTENED
BACK
O
PCB OUTLINE
Figure 10. Transistor Orientation Guide.
ELECRAFT 25
OTC
Install U9 (77L06) below RP5 on the lower edge of the board
using the same procedure that you used for U8 above. Be sure the top
of the device is no more than 5/16” (7.9 mm) above the board.
Install transistor Q7 (2N4124). The position for Q7 is in the upper
right quadrant of the board, about 1” (2.5 cm) down from the top edge
and 1-3/4” (4.4 cm) from the right hand edge. Be certain the top of the
transistor is no more than 5/16” (7.9 mm) above the board.
Install 8-pin integrated circuit U3 (4427) in the space provided
near the right hand edge of the board, about 1-1/4” (3.3 cm) down
from the top edge as follows:
_ Test-fit U3 to see if the pins line up with the holes in the
solder pads on the board. If needed, straighten the pins like
you did for resistor pack RP5 (see Figure 5).
_ Identify the end of U3 where pin 1 is located. It will have a
notch, a dimple, or both at this end (see Figure 11).
_ Insert U3 into the solder pad holes with the notched, pin 1
end lined up with the notch on the printed outline.
_ Spread out the pins on the opposite corners to hold U3 in
place, then solder and trim all 8 pins.
N
H
Install 3-digit LED display DS1 as follows:
_ Insert the 3-digit LED display in the space bounded by
resistor packs RP1, RP2, RP3 and RP4. The pins on DS1
allow it to be inserted only one way.
_ Hold the display against the board and tack-solder pins at the
opposite corners.
_ Inspect the display carefully to ensure that it is firmly against
the board at both ends. If necessary, reheat one of the pins
and adjust the display. It is very important that the display be
fully seated and resting directly against the board at both
ends.
_ Solder and trim all 13 pins on the display.
Install encoder Z1 as follows. Z1 mounts to the left of
transistor Q7.
_ Test fit Z1 on the board. It will only go one way. The side
with three terminals is nearest the top of the board.
_ Press down on Z1 until the small nubs at each corner rest
directly against the board. It is very important that Z1 be fully
seated against the board.
_ Solder two pins on opposite corners of the encoder, then
recheck to ensure it is sitting against the board. If necessary,
reheat the solder and press down on the encoder to position it.
_ Solder the two large tabs to the plated ring around the edge of
the mounting holes. Apply only enough solder to make a
DIMPLE A T
PIN 1
Figure 11. IC Alignment.
good mechanical and electrical connection between the tab
and circuit board. Do NOT try to fill the holes with solder.
_ Solder and trim all five pins.
26 ELECRAFT
Visual Inspection
Verify correct orientation (banded end) of diodes D2 and D3,
using the parts placement drawing (Appendix F).
Verify the correct orientation of each electrolytic capacitor. The
side of the capacitor with the strip and minus ( - ) sign must face away
from the + sign printed on the board.
Examine both sides of the PC board closely for solder bridges,
cold solder joints, or unsoldered components.
Resistance Checks
Make the resistance checks listed below with your DMM’s
negative (-) lead connected to the circuit board ground at the screw
hole just above capacitor C6.
Test Point (+) Resistance
U1 Pins 1, 3, 4, and 20 > 1 k
U1 pins 8 and 19 < 5 ohms
U1 all other pins > 10 k
U3 pin 3 < 5 ohms
U3 all other pins > 10 k
D2 or D3 cathode
(banded end), S1 On
D2 or D3 cathode,
S1 Off
> 1 k
> 10 k
ELECRAFT 27
Alignment and Test - Part I
In this section you’ll become familiar with basic KX1 operation, while
testing the control and display functions.
i
Microcontroller U1 is extremely static-sensitive. Wear a
wrist strap or ground yourself before handling U1.
Remove microcontroller U1 from its conductive foam packing
and inspect the pins. The two rows of pins must be straight and
parallel to each other to establish the proper pin spacing for insertion
into the socket. If necessary, straighten the pins as shown in Figure 5.
Identify the end of the IC where Pin 1 is located. It will have a
notch, a dimple or both at this end (see Figure 11).
i
When U1 is pressed into its socket, you must be careful to
avoid jamming its pins. Make sure all the pins are lined up with
the associated holes before pressing down on the IC. Watch the
pins on both rows as you press down to be sure each pin goes
straight down into its socket hole and does not bend in under the
IC or outward alongside the socket. Realign each pin individually
with its socket hole, if necessary.
Press down very firmly on U1. If it is not seated as far as
possible into its socket, the pins may not make good contact.
Temporarily mount the VFO knob on the shaft of encoder Z1.
Align the set screw with the flat side of the encoder shaft and tighten it
using the Allen wrench supplied.
i
You may notice some side play in the encoder shaft. This is
normal in miniature shaft encoders with an integral pushbutton
switch.
Set slide switches S1 and S2 to the OFF position.
Connect an 8 to 14 VDC power supply to J1 with the positive (+)
lead to the center pin. A mating connector for J1 is supplied with the
kit. If you use a power supply voltage of less than about 10.5 volts,
you may see a BAT LO message flashed on the LED during initial
tests. This is because the BAT menu parameter is set to 10.0 volts by
default. You can set the BAT parameter to a lower value to eliminate
the warning message.
Unwrap the cover and set it near the circuit board so you can see
the legends identifying the switches and their functions.
Insert microcontroller U1 in its socket with pin 1 or the notched
end lined up with the notched end of the socket (the end closest to the
edge of the board).
i
If any test or alignment step fails, refer to the
Troubleshooting section (Appendix E).
28 ELECRAFT
LED Tests
i
When testing the lamp in the following step, do NOT look
directly at the white LED. It is very bright.
Switch S1 (LAMP) On and verify that D1 lights, then turn it Off.
Switch S2 (POWER) On. If you see or smell smoke, or a
component feels hot to the touch, switch S2 Off and disconnect the
power source immediately. Locate the source of trouble before
proceeding.
You should now see either E10 or 00.0 on the 3-digit LED
display. E10 is an informational code that indicates that the EEPROM
(configuration memory) on the microcontroller has been initialized to
default values. This message will appear only once, and can be cleared
by tapping any of the three pushbutton switches. 00.0 is a portion of
the VFO frequency, which is set to 7100.00 kHz the first time you turn
power on. The display format will be described in a later step.
i
After a few seconds, the display turns off automatically if
you haven’t touched the VFO knob or pressed any switches. This
is intended to extend battery life. Moving the VFO knob or operating
one of the pushbutton switches will turn it on again. (The display time-
out is programmable. This will be discussed in the next section.)
Voltage Checks
Connect your DMM’s (-) probe to circuit board ground at the
screw hole next to capacitor C6. Use the (+) probe to check the
following DC voltages:
_ U1, pin 1: 5±0.25 Vdc
_ U3 pin 6: 6±0.25 Vdc
_ D2 anode: Supply voltage.
_ D2 cathode (banded end): supply voltage – 0.3 Vdc (approx).
Leave your DMM’s (-) probe connected to the circuit board
ground, and set your DMM for a 200 to 300 millivolt AC range.
Check the AC voltage at the following pins. A higher voltage than
shown may indicate a problem with one of the voltage regulators as
explained in the note below.
_ D2 anode: < 20 mV AC rms.
_ D2 cathode (banded end): <20 mV AC rms.
_ U1 pin 1: <20 mV AC rms.
_ U3 pin 6: <20 mV AC rms.
i
The 2.7 V and 6 V regulators used in the KX1 (U7 and U9,
respectively) are low-dropout types, which may oscillate if their
bypass capacitors are defective or are of the wrong value. If you
see high AC voltage at any of the points indicated above, verify
that electrolytic capacitors C7, C10, and C38 are installed in the
correct orientation and that their leads are properly soldered. If
they are, you may be seeing a false AC voltage indication due to
noise or probe leakage; re-test using a different DMM.
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