K1EL K44 User manual

K1EL K44-KIT CW Keyboard/Reader Kit Assembly Guide Rev A
K44 Kit Assembly Guide Rev A PCB 5/20/2020 Page 1
Introduction
This document will describe how to assemble and test the K44 Keyboard/Reader Kit. The assembly of a K44 is
not very difficult, but is probably not a good “first kit” since there many challenging assembly steps. Before you
start working on the kit you will need to gather the following items
1) A low wattage (40W) soldering iron or pencil or temperature controller solder station.
2) Good grade of Rosin core solder, Please do not use ACID CORE Solder !!
3) A good pair of wire cutters, small pliers, assorted screwdrivers, and a 5/64” Allen wrench
4) A Volt Ohmmeter or DVM is required for several assembly steps
5) A magnifying glass is very helpful
6) Power supply providing a voltage between 8 to 13 VDC (9VDC is optimum) at about 250 ma.
7) Optional: An audio signal generator or radio receiver with a calibrate function.
It is very important to take your time and carefully follow the instructions and assembly photos.
The main tasks are 1) Identify components, install them in the correct board location and then do a good job
soldering them in place. Experienced builders will have no problem with the process but others will have to take
their time and carefully examine the board photos and refer to the bill of materials often. Please don’t assemble
the kit in a manner other than as described, the order of the steps is very important from a mechanical
perspective and if you don’t follow them you can end up with a kit that can’t be completed.
As mentioned, these instructions assume you have basic electronic kit building experience and can identify
different types of electronic components. Photos are provided which will greatly aid in assembling the kit
correctly. The instructions don’t provide component by component instruction but more of a general section by
section flow. The biggest enemy of kit success is poor soldering, so please take care with each solder joint, and
use just enough heat to get a good connection. A good joint should be both shiny and smooth. Even experienced
builders can benefit from reading Appendices A, B & C at the end of this document.
Bill of Materials
The bill of materials is listed below. The first step is to inventory and identify all parts ahead of time. This will
allow the assembly to proceed smoothly. Let us know if you are missing any parts.
Reference Des. Qty Part Description Package Other Info Check Off
R10 1 100 ohm Resistor 1/8 Watt Brn Blk Brn _________
R8,R12 2 10K ohm Resistor 1/8 Watt Brn Blk Org _________
R16 1 47 Ohm Resistor 1/8 Watt Yel Violet Blk _________
R13,R14,R11,R20 6 470 Ohm Resistor 1/8 Watt Yel Violet Brn _________
R21,R23
R15,R17,R18,R19,R22, 9 4.7K Ohm Resistor 1/8 Watt Yel Violet Red _________
R3,R4,R1,R7
R9 1 47 ohm 1/2 Watt Yel Violet Blk _________
R6 1 5.76K Ohm 1% Resistor 1/8 Watt Blue Axial _________
R2 1 33.2K Ohm 1% Resistor 1/8 Watt Blue Axial _________
R5 1 66.5K Ohm 1% Resistor 1/8 Watt Blue Axial _________
C3,C4 2 .001uF Capacitor (102) Ceramic Disk .2” spacing _________
C1,C16,C19,C2,C21 8 .1uF,Capacitor (104) Ceramic Disk .2” spacing _________
C14,C15,C20
C22,C23,C5,C6,C13 5 .01uF,Capacitor (103) Ceramic .2” spacing _________
C7 1 .1uF Capacitor (104) Mylar film .2” spacing _________
C11,C12 2 .012uF Mylar Cap (123) Mylar film .2” spacing _________
C9 1 .47uF Capacitor (104) Ceramic .2” spacing _________
C17,C18,C8 3 33uF Electrolytic Cap Radial .1” Spacing _________

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C10 1 100uF Electrolytic Cap Radial .1” Spacing _________
L1,L2 2 1uH,Inductor Leaded Ferrite leaded _________
U1 1 AQW280EH SS Relay 8 pin DIP no socket _________
U4 1 16F1825 Keyer PIC 14 pin DIP socketed, dot _________
U2 1 CY8C27143 PSoC 8 pin DIP socketed _________
U3 1 MCP6002 Dual Op Amp 8 pin DIP no socket _________
U6 1 16F1825 Console PIC 14 pin DIP socketed _________
U7 1 24LC32A Serial EEPROM 8 pin DIP no socket _________
U5 1 12F508 LED Driver PIC 8 pin DIP no socket _________
Q1 1 PN2222A Transistor TO-92 _________
D3,D4,D5,D6,D7 5 CWR Tuning LED Right Angle Green _________
D2` 1 CWR Tuning LED Right Angle Red _________
D1 1 1N4001 Diode DO-41 _________
VR1 1 LM7805 5 Volt Regulator TO220 _________
DP1 1 Sunlike SD1602H LCD Display PCB Module _________
SP1 1 Mini Speaker _________
J1,J2,J3 3 Stereo Phone Jack 1/8 Inch Jack AF, Key, Pdl _________
J4 1 Keyboard Connector PS2 6 Pin DIN _________
J5 1 Power Connector 2.5 mm female receptacle _________
P1 1 Power Connector 2.5 mm male plug _________
ENC1 1 Rotary Encoder Panel Mount _________
ENC-BKO 1 Encoder Breakout Board Small PCB _________
MISC 1 K44 Enclosure _________
MISC 1 Control Knob Plastic 1/4” shaft _________
MISC 4 Rubber Feet Press in _________
MISC 1 16 pin Header Right Angle Tinned leads _________
MISC 3 4-40 Hex Nuts w/lock washers _________
MISC 1 K44-KIT Rev A PC Board _________
MISC 4 4-40 1/4” Screws Black for enclosure cover _________
MISC 5 4-40 1/4” Screws For PCB & heatsink mounting _________
MISC 2 14 pin DIP socket for U4 and U6 (Keyer & Console PICs) _________
MISC 2 8 pin DIP socket for U2 (PSoC) _________
MISC 1 10” length of hook up wire _________
MISC 1 Heatsink _________

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K44 Kit Assembly Instructions
First task is to assemble the K44 PC board. It will progress in sections, a picture will accompany each section.
We will start with the resistors, the color codes are listed in the parts list. We recommend verifying values with an
ohmmeter. 1/8 watt resistors can be difficult to read and it is difficult to unsolder them. Use Figure 1 below as a guide.
Note that there are two 47 ohm resistors, a large one (1/2W) and a small one (1/8W). The large one goes in R9 and
small one in R16.
Note about precision resistor installation. These are the three blue colored resistors. The color code is very hard to
read on these, Please use either an ohmmeter to sort them out. They are far enough apart in value so it’s pretty easy.
Note that depending on your meter’s calibration and the tolerance of the resistors, you probably will not read the
exact value but all we are trying to do is sort them into three values: 5.76K, 33.2K, and 66.5K.
Figure 1 – Section 1: Resistor Installation

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Continue with the ceramic capacitors, followed by three mylar capacitors. Next install the leaded ferrite beads L1 & L2
and three IC sockets. Final installation in this section is diode D1 with the polarity marker on the left as shown.
Figure 2 – Section 2: Capacitor, Sockets, Ferrite, and D1 Installation

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This section starts with the LEDs D2-D7. Install them so that they are all even with the front edge of the board and
there is equal space between them. Save the Red LED for last at position D7. The best thing to do is start in the
middle and work your way right and left. Put in D4 first, tack solder one lead and tweak the placement to get the front
edge aligned right. Then install D5 the same way and space it so that D4 and D5 are not touching and there is about
1/32” gap between them. Go back and forth D4, D5, D3, D6, D2, and D7. It should look at least as good as the
picture below when you are done. Please spend extra time with this because you will see the bodies of the LEDs
through the front panel and the better they look, the better the whole assembly will look.
Now install ICs: U1, U3, U5, and U7 which don’t require sockets. Be sure that the dimple on the top of the IC aligns
with the silkscreen number 1. You will have to carefully bend the IC pins in to get them to insert into PC board. See
picture below. Complete this section with Q1, flat side aligned with the silkscreen.
Carefully bend IC leads
Figure 3 – Section 3: LED, IC, and Q1 Installation

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Start section 4 with the connectors J1, J2, J3, and J4. Make sure that each one is fully seated in the board before
soldering. It’s best to do them one at a time. It’s important to align these connectors correctly and neatly with the
silkscreen so that they will fit properly in the metal enclosure.
The electrolytic capacitors are installed with the polarity bands facing as shown (long lead into square hole). Install
the mini speaker with the plus side facing R16. After soldering remove the protection sticker. Solder VR1 in place, tab
away from C2. If you are not going to use the optional on/off switch, solder a jumper between pads S1 and S2. If
undecided, you can cut or remove the jumper and add the switch later. (See page xx for more details)
Before installing the socketed ICs, make up a power supply cable to test the board. A mate to J5 is included in the kit.
Solder two wires to the connector, with the plus lead on the center pin. If you have a 9 to 13VDC wall wart supply with
a 2.5mm connector, center pin positive, that will work fine. Current rating must be greater than 100 mA. Double
check that the center pin of the power connector is positive with respect to the shell and then plug it into J5. The K44
does have a polarity protection diode but it’s worth the extra step to make sure the cable is right.
Apply voltage to the board and you should measure 5 volts between the R9 and the tab on VR1 (GND). If you don’t
see 5 volts you will need to do some detective work. First of all, verify that your cable is wired correctly. Then make
sure that VR1 is installed correctly and that all the electrolytics are installed as shown in the picture. If that’s ok you
will need to examine your solder workmanship to be sure there are not solder shorts or missed solder connections.
Once this is verified you can install U2, U4, and U6. You will need to bend the IC pins in order to get them to fit in the
sockets (see Fig 3). Note that pin one of each IC (dimple) must align with the 1 on the silkscreen. Note U4 has a red
dot, U2 has a silver dot, and U6 has no dot.
Figure 4 – Section 4: Connector, Electrolytic, VR, and IC Installation

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Following are some close ups of the board to help verify part placement, Note that R10 is not installed:
Figures 5 & 6 – Close Up Views

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LCD Installation
This is the most challenging step in assembling a K44. Please read through the entire procedure so that you fully
understand how it is done. If you make a mistake here, it will be very difficult to fix it so go slowly and follow each step
closely. Some assembly pictures were taken with a previous revision of the K44 pcb board, but the display
assembly procedure is exactly the same.
NOTE: the LCD module uses a delicate film ribbon interconnect which can be easily torn or damaged by soldering
iron. When picking the display up try to hold it by the sides avoiding contact with the ribbon.
Figure 7 – Caution, do not damage ribbon film interconnect
Begin by installing four rubber feet into the bottom of the enclosure base and set it aside for now.
Figure 8 - Rubber feet in place on bottom half of enclosure
Insert the 16 pin header into the LCD module as shown in figure 5. The plastic bracket on the display module may
make this a bit difficult. If you start with the header at an angle it will help. Once in place, make sure the header is
fully seated and on the correct side, but do not solder this yet !
Figure 9 – Insert header into display module – DO NOT SOLDER THE PINS YET !!

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Now fit the unsoldered LCD/Header sub-assembly into the K44 PC board as shown in figure 10.
Figure 10 – Insert subassembly into K44 PC board
Now slide this loose sub-assembly in place into the enclosure base. Carefully fit the display notches over the
threaded studs on the front panel. Note that the header should naturally seat into both the LCD module and K44
board, if you find yourself forcing anything you probably have something misaligned.
Figure 11 – Slide subassembly into K44 enclosure base on threaded studs

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Attach the K44 PC board to the base with two 4-40 screws. Then fix the LCD display to the front bezel with two 4-40
nuts. Use just enough force to hold the display in place so it is nearly flat against the front panel and centered in the
enclosure display window. DO NOT USE A NUT DRIVER, tighten by finger force only !!!
Figure 12 – Add 4-40 nuts and screws to hold subassembly in place
Figure 13 – Close up of display fixed to front panel (DO NOT OVER-TIGHTEN DISPLAY NUTS !!)
Double and triple check the alignment and make sure the header is fully seated into the LCD display module. Loosen
the display nuts if necessary to get a good centered display alignment then re-tighten

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Figure 14 – Center the display window in the enclosure opening
Sometimes during handling, the header will slip out of the LCD display module. Before soldering, you may have to
very gently pull the header back into the LCD module with thin long nose pliers or tweezers. We want all of the
header pins to stick out roughly the same on each end.
Figure 15 – Gently adjust header for equal pin alignment
Now carefully solder the two end pins on the LCD module and then two end pins of the header to the K44 board. It’s
easier to get at pin16 on the K44 board since it is further away from D2’s LED housing.
Figure 16 – Solder four places to fix display alignment
Remove the two 4-40 nuts, and two 4-40 screws. Then extract the assembly from the enclosure base. Solder the
unsoldered pins on both sides of the header. Be sure to NOT start with the end pins you soldered in the previous step
because that will spoil the display alignment.

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Figure 17 – Solder remaining connections on display
Figure 18 – Solder remaining connections on bottom of K44 board
Display assembly is now complete !
Now it’s time to work with the rotary encoder. Locate the rotary encoder and encoder PCB seen below. Make sure the
threaded encoder shaft fits into its mounting hole on the K44 enclosure’s front panel. You may need to remove some
paint on the inside of the enclosure hole to get it to fit.

Figure 19 - Encoder and encoder PCB

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Prepare five wires, two are 2.5 inches long and three are 1.5 inches long. Strip and tin both ends. Solder wires to
PCB as shown in figure 17. This step is much easier if you use a board vice or clamp to hold the encoder board
steady while you solder wires to it.
Figure 20 - Wires attached to encoder board
Mount the encoder on the correct side of the PCB per text on PCB. It’s not necessary to completely fill the bracket
mounting holes with solder.

Figure 21 - Encoder on encoder PCB
Solder the 5 wires from the encoder PCB to the K44 PCB as shown, starting with E1 to E1, then E2 to E2, E3 to E3,
S1 to S1, and finally S2 to S2. Avoid hitting the plastic wire insulation with your soldering iron.

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
Figure 22 - Encoder PCB attached to main K44 PCB
Peel off the thin protective film from the front of the LCD display.

Figure 23 - Don’t forget this step or the display will appear foggy !

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Re-install the PC board assembly into the chassis by carefully folding the board back in place first on to the threaded
studs then on to base mounting studs. Install and tighten the four silver 4-40 board mounting screws. Please do not
reinstall the two display hold down nuts. The soldered header is mechanically strong and is all that is needed to
support the display. More often than not, builders will over tighten the nuts and damage the LCD display or under
tighten them so they work their way loose and fall on the board causing a damaging short circuit. Bottom line, do
not install the display holding nuts !!
Figure 24 – Rear view with encoder and display in place
The encoder is mounted with one hex nut and one flat washer. The washer and nut both go on the front of the unit.
Reference the picture above to see how this is done. Be careful when tightening the nut, it’s easy to slip and scratch
the front panel. Now attach the rotary encoder knob using a small Allen wrench.
Figure 25 – Placement of encoder flat washer and hex nut

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Attach heatsink to 5 volt regulator as shown:
Figure 26 – Heatsink Installation
We will leave the top cover off until we have completed the K44 Test Procedure.
K44 Test Procedure
1) First thing to do is attach the K44 to power. The K44 accepts a 2.1 mm power connector with center pin
positive. The supply voltage should be in the range between 7 to 13.5 VDC at 150 mA. As soon as power is
applied, the LEDs will run a self test pattern. D1->D2->D3->D4->D5 then in reverse. This is followed by two
alternating LED patterns. All LEDs will turn off after the test is complete.
2) During the LED test, the LCD backlight will turn on followed by a start up message. This message will
display the PIC and PSoC versions along with other status as indicated in the figure below. If the display
contrast is not satisfactory, we will show how to adjust it in step 3. After the LED test completes, the K44 will
send an ‘R’ in sidetone, and the start up display will automatically clear leaving an underline cursor.
Figure 27 – Start Up Display with revision locations A, B, and C
3) Console PIC Test: Turn K44 power off by disconnecting power. Now attach a PS/2 keyboard and turn the
power back on. We need to load a default keyboard table before we proceed. Simply press the Scroll Lock
key and you will see FCR? displayed. Respond by hitting Scroll Lock again and the K44 will restart, load a
keyboard table, and display QWERT. Now when you type on the keyboard you will hear CW sent in
sidetone and also see letters displayed on the LCD display. If you want to change the keyboard mapping
press CTL-ALT-INS and you can toggle between QWERT and AZERT layouts. Now that we have a
keyboard attached we can adjust the display contrast. Press ALT-LEFT and ALT-RIGHT to change contrast.

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4) Keyer PIC Test: Plug a keyer paddle into J3, it’s assumed that your paddle set cable has an 1/8” stereo
plug with left paddle connected to the tip. When you press the paddles you should hear dits when the left
paddle is pressed, dahs when the right paddle is pressed, and alternating dits/dahs when both are pressed.
5) Keying Output Test: Make up a keying cable that has an 1/8” stereo connector on one end (K44) and an
appropriate key connector on the other side that will plug into your transceiver keying input. This is usually a
1/4” phone plug. Before plugging into your radio, it’s a good idea to verify keyer output by measuring the
resistance across the tip and sleeve of the key connector. When you key either by paddle or keyboard, you
will see the resistance vary with keying. If you measure between ring and sleeve, you will see the PTT
resistance go low as long as keying is active. Meter lead polarity doesn’t matter since the output acts like a
switch contact.
GndPTTKey
Key Line
to XCVR
Figure 28 – Key Output Connector
6) PSoC IC Test: During power up two LED test patterns are displayed. The second test shows two alternating
LED patterns (two and three LEDs) which test the path between the PSoC and the LED controller. To test
the PIC to PSoC path enter ALT-F2 and the default CWR speed will be displayed.
7) Rotary Encoder Test: Simply turn the encoder and you should see the current WPM value updated on the
upper left side of the LCD display. The WPM value will increase when you turn clockwise and decrease
when you turn counter-clockwise. The WPM readout will disappear a few seconds after you stop turning the
encoder.
8) This is an optional test; if you have an audio frequency generator you can run a quick test. First of all, power
up the K44 and hit the ALT and then F1 keys and you should see CWR On displayed.
Now in order to feed audio into the K44 you will need to make up an audio cable. This will consist of an 1/8”
mono or stereo plug on one end and bare leads on the other. Audio will be applied between the tip and
sleeve of the connector. On your signal generator, select a frequency range that will cover a sub range close
to 500Hz through 1000Hz. Set the output lever to minimum and connect the K44 audio cable leads to the
signal generator output. Now plug the other end of the cable into the K44. Set the frequency to 725 Hz and
slowly increase the signal level until you see the LEDs start to light. Stop when you see the rightmost red
LED turn on. Now adjust the frequency back and forth around 725 Hz and you should see a definite peak
close to 725Hz. It may not be exact due to signal generator calibration or allowable error in the K44. As long
as it’s close and there is a definite peak we are done. If you don’t see this, the first thing to check is the
placement of the three precision resistors followed by C11 and C12.
9) Using a receiver as an audio source brings up several issues. If you simply plug into a receiver’s external
speaker output you will not be able to hear anything because you are replacing the speaker output with the
K44 which only consumes audio and does not have its own internal speaker. The ideal place to take
receiver audio from an audio line out connector. Every radio is different, some put this on a connector
labeled RTTY, Packet, Data, or if you are really lucky, and RCA jack marked Line Out. Odds are the line out
connection is on a DIN connector which might be labeled AUX, AUX1, or AUX2. The beauty of using Line
Out is that it is a fixed level not influenced by the AF gain control.
If you want to skip line out, you can do a quick connection by using an external speaker connection and
connecting that to an external speaker. Then tap K44 audio across the speaker. Be sure to connect the
speaker’s ground side to the K44 cable ground.
10) Now is the time to give the K44 a good workout, go through the K44 User Guide and try out some of the
commands and message features. It will take some time to get through everything. If you have not done it,
take some time to make up any interconnecting cables you may need, the following diagram shows the
connector layout on the K44 rear panel. Note that stereo plugs are shown in the drawing below. A stereo
plug is only required if you want to use PTT or two keying ports on the Key Out jack.

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Gnd
Iambic
Paddle
PS/2
Keyboard
6 - 11 VDC
Dah
KBD KeyOut
PDL
Audio
In
PWR
Gnd
PTT
Key
Gnd
Audio
Input
N/C
Plus
Key Line
to XCVR
Gnd
Dit
AF
Figure 29 – K44 Back Panel Connections
Final Assembly
To install the top cover, reference the following picture. Angle the top cover and get the rear connectors to start to go
into the cover. Then fold the cover down to meet the front panel and push it forward so the three 1/8 inch connectors
poke out the back evenly. Install the four black 4-40 screws to hold the cover in place.
Figure 30 – Fold top cover into place

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Fig 31 - Completed Unit Front View
Fig. 32 - Completed Unit Rear View
R10 Information
This is an optional install and is not required for normal operation of the K44. R10 routes post filter audio to the ring
of Audio In jack on the back panel. The intent was to provide a way for the user to extract in band audio from the K44
and feed it to an audio amplifier. This allows the user to hear peaked CW at the K44 decode frequency making it
slightly easier to tune and decode a CW station. In practice it is not much of an advantage due to the extra cabling,
shielding, and the necessity of an external audio amplifier. Unless you have a definite plan to use this feature we
recommend leaving R10 out.

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CW Keyboard Theory of Operation
This section will cover the CW keyboard portion of the K44. It can be helpful to read through this to get familiar with
the circuitry if you are debugging the K44.
As shown in the block diagram below, two PIC processors share the task of converting keystrokes to Morse code.
U6, the console PIC, is responsible for retrieving keystrokes from the keyboard and determining what to do with them.
U4 is the Keyer PIC which is controlled by the console PIC, its main task is to generate Morse code and monitor the
keyer paddle inputs. The two PICs communicate over a serial interface running at 9600 baud. The Keyer PIC throttles
the Console PIC via in-band flow control. A 4-kilobyte EEPROM memory, connected to the Console PIC’s SPI
interface, stores up to 12 messages, system settings, and holds the keyboard type ahead and LCD display buffers.
Figure 33 - K44 CW Keyboard Block Diagram
There are two types of data sent from the Console to the Keyer: Commands and Data. Commands modify the K44's
operation in some way; changing operating speed, turning off sidetone, recording a message, etc. Data are letters,
numbers, or prosigns that are to be sent in Morse. Data is processed differently than commands. Data is put into a
type ahead buffer that allows the user to type faster than the Morse is being sent. The size of this buffer is about 200
characters and is a FIFO buffer (First In First Out) meaning that characters are taken out in the order they were put
in. Since there can be a considerable delay from keyboard input to Morse output, commands bypass the input FIFO
and are sent to the Keyer PIC immediately. This allows changes to be made while sending is underway.
Figure 34 – Output FIFO Block Diagram
Since there are cases when you don't want commands to take effect immediately, the K44 buffers certain commands.
This means that the command is placed in the typeahead buffer and won’t be acted on until it comes out. An example
of the use of a buffered command would be to send two words at two different speeds, the first at 15 WPM and the
second at 20 WPM. By placing a buffered speed command between the words the speed will not be changed until
the first word is completely sent. Not all, but many of the immediate commands can be entered as buffered
commands. Most often, buffered commands are used in messages.
Getting back to the block diagram, the paddle inputs are connected to the Keyer PIC, the paddle takes priority over data
coming in from the keyboard. A paddle press will cause the FIFO buffer to be cleared. This allows you to cancel a
message and start sending by paddle right away. As mentioned before, the keyboard is connected to the Console PIC
since its input generally has to be buffered in the EEPROM. The LCD is also connected to the Console to allow keyboard
data and command prompts to be displayed. The K44 keeps two separate display buffers in EEPROM, one that tracks
keystrokes as they are entered and a second which shows data as it is being sent by the Keyer PIC.
FIFO
Key
Processor
Key Input
Command
Bypass
Output to Keyer PIC
Serial I/F
Keyboard
EEPROM
Memory
Key
PTT
Keyer Paddle
LCD
Display
CWR
AF Input
Speaker
Serial I/F
U4
Keyer
U6
Console
Opto
coupler