QRPGuys Pacificon KD1JV User manual

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The KD1JV Pacificon
A DSB/CW transceiver for 40 meters.
Featuring: Wide tuning range digital VFO with 5 digit LED readout.
Direct Conversion receiver
~5 watt CW/PEP transmitter
The CalQRP club wanted a simple transceiver with voice capability for a Pacificon build-a-thon. The
goal was to have a QSO party using the project at the end of the build-a-thon.
The other two design goals were low cost, reasonably simple design and hopefully most can build
it in under two hours. DSB was chosen since it's a lot simpler to implement then a SSB transceiver
and is somewhat more effective than AM.
Conventional wisdom says two DSB stations can't talk to each other if both use a Direct
Conversion receiver. This is not true.
What is true is that the two stations need to match each other's frequency exactly. Or at least
really close. As the center frequency of one or the other (or both) stations start to drift apart, the
beat note of each side band starts to separate, with annoying results.
The problem with minimalist DSB designs is that they often used an Analog VFO of questionable
stability. So, keeping two home brew DSB stations on the same frequency was frustrating, hence
the bad rap.
By using the inexpensive Si5351 clock chip for the VFO and the various additional functions a
microprocessor adds, The Pacificon becomes a practical DSB rig.
The firmware is written with the Arduino IDE. The MEGA328P processor comes with the bootloader
installed, making it compatible with the UNO board for reprogramming. The Arduino sketch is
available to tinker with.
A Baofeng UV3R, (not UV3R+), single plug microphone is required for voice operation. These are
available on ebay for $5 to $10 depending on who you buy from and how long you want to wait
for it.

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Specifications:
 DSB/CW Transceiver for 40 meters.
 Tuning range 500 kHz to 30 MHz (actual range limited by band filter
characteristics)
 Direct Conversion (DC) receiver.
 Receiver MDS: ~0.5 uV
 Audio Bandwidth: Wide: 4,000 Hz Narrow : 1,000 Hz
 Double Side Band (DSB) transmitter. Up to 5 watts PEP, ~5 W typical. (power is
split between two side bands, so effective PEP is 2.5 watts)
 CW Transmit Mode. Up to 5 watts.
 Rx current : ~40 ma
 Tx Current : (CW) ~650 ma @ 13.8 V, 4.5 watts out.
 TX spurs, well below -50 dBc.
 12 to 14V supply
Assembly:
The first step is to sort the parts into groups of similar types. Doing this now will save
time later.
Print the placement diagram below for easy reference. Experienced builders will need
little more than this diagram.
Part locations are color coded using the resistor color code to indicate the zero multiplier
of the part value to be placed there. Since several values use the same zero multiplier,
pay attention to the most significant digits.

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Parts list:
QTY Value Code QTY Value Code
2 5.6 ohms Grn/Blu/Gld/Gld 16 100 nF (.1uF) 104
1 10 ohms Brn/Blk/Blk/Gld 5 10 nF (.01 uF) 103
1 51 ohms Grn/Brn/Blk/Gld 3 1 nF (.001uF) 102
1 150 ohms Brn/GRN/BRN/Gld 2 680 pF 681
13 2.2K Red/Red/Red/Gld 3 330 pF 331
2 4.7K Yel/Vio/Red/Gld 1 68 pF 68
8 10K Brn/Blk/Org/Gld 2 47 pF 47
1 22K Red/Red/Org/Gld
2 47K Yel/Vio/Org/Gld 3 1 uF/25V electrolytic
3 100K Brn/Blk/Yel/Gld 5 100 uF/16V electrolytic
1 470K Yel/Vio/Yel/Gld
2 1M Brn/Blk/Grn/Gld
1 25K 9mm pot 1 Si5351A
1 2K 6mm trimmer 1 1N5817
5 1N4148
3 10 uH molded inductor 1 2N3906 PNP TO-92
2 2N3904 NPN TO-92
1 16.000 MHz HC-49S 8 BS170 MOSFET TO-92
1 25.000 MHz HC-49S 1 LM78L05 5V reg TO-92
1 LM78L09 9V reg TO-92
1 5 digit 7 seg LED display 0.38” 1 ATMEGA328P AVR processor
1 SA602 or 612A Mixer DIP
2 T37-2 Red Toroid 1 LM356 Dual opamp DIP
2 FT37-43 Black Toroid 1 LM386 Audio amp DIP
3 8 pin DIP socket
1 6 feet #26 red magnet 1 28 pin DIP sokt
1 1 foot #26 grn magnet 1 12mm encoder
1 PCB BNC jack
1 pcb Pacificon pcb 1 3 ring 3.5mm
jack
Mic/spkr jack
1 5.5-2.1 mm DC power jack
2 SPDT slide
switch
2 3 wire plug &
socket pigtail
External spkr &
keyer connections

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[] Solder U4, the Si5351A smd component first. Position as shown below. Note
orientation of Pin1. Be sure there are no solder bridges between pins. Use Solder Wick® if
necessary to remove any excess.
Resistors:
Some values who's color codes are very similar are easy to mix up. It's important to
pay attention to the multiplier band to make sure you have the correct decade. Pay
attention to the 2.2K and 22K, 4.7K, 47K and 470K values, along with 51 ohms and
1M. These are easy to mix up. When in doubt, use a ohmmeter to measure.
Locations are numbered on the board left to right, starting at the upper left corner
and then zigzag down the board.
[] 5.6 ohms - R1, R5 (Green-Blue-Gold-Gold)
[] 10 ohms - R35 (Brown-Black-Black-Gold)
[] 51 ohms – R12 (Green-Brown-Black-Gold)
[] 150 ohms - R13 (Brown-Green-Brown-Gold)
[] 2.2K – R4, R6, R9, R10, R23, R27, R28, R29, R30, R31, R32, R33, R34, (Red-Red-
Red-Gold)
[] 4.7K – R7, R15 (Yellow-Violet-Red-Gold)
[] 10K – R2, R14, R17, R19, R20, R24, R25, R26 (Brown-Black-Orange-Gold)
[] 22K – R21 (Red-Red-Orange-Gold)
[] 47K – R3, R11 (Yellow-Violet-Orange-Gold)
[] 100K – R8, R16, R18 (Brown-Black-Yellow-Gold)
[] 470K – R22 (Yellow-Violet-Yellow-Gold)
[] 1M – R36, R37 (Brown-Black-Green-Gold)
Inductors (RFC):
[] 10 uH – L1, L2, L3 (Brown-Black-Black-Gold or Silver)
Diodes:
[] 1N5817 – D1 – Black plastic body, silver stripe on one end, match silkscreen
[] 1N4148 – D2, D3, D4, D5, D6 – Glass body, black stripe on one end, match
silkscreen
Capacitors:
Since most of the caps are 100 nF (104), we'll put all of those in first. Look at both
sides of the capacitors carefully, as most have a confusing date code on the reverse.
[] 104 – C1, C5, C8, C9, C10, C11, C14, C19, C21, C23, C28, C31, C35, C36, C39,
C40

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[] 331 - C2, C3, C37
[] 681 - C4, C27
[] 68 - C6
[] 103 – C13, C22, C26, C30, C32
[] 102 – C7, C12, C15
[] 47 – C18, C20
Crystals:
[] 25.000 - X1
[] 16.000 - X2
Sockets:
[] 8 pin DIP – U1, U2, U5
[] 28 pin DIP - U4
 Make sure to line up the notch on the socket with the one on the board
outline.
 Check to make sure all the pins are sticking out of the holes before you
solder more than one pin. Finding a pin rolled under the socket after all the
other pins have been soldered is not an easy fix.
LED Display:
Now is a good time to install the display, before the higher profile parts start to
get in the way of the soldering iron.
[] LED Display – flip the board over and install the display flush with the surface.
 It will go in only one way due to a missing pin and corresponding pad on
the board.
 Clip the leads while you can still get the cutters in there.
Transistors:
[] BS170 - Q2, Q3, Q4
 These are mounted with the flat side of the package flat to the circuit board
for heat sinking.
 Bend the leads towards the flat side at a 90 degree angle, about 1/8” from
the body.
 Make “U” shaped wires from resistor lead clippings to hold the package
down onto the board, using the solder pads on either side of the package.
 Solder the BS170 leads.

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[] BS170 – Q7, Q8, Q9, Q10, Q11
[] 2N3904 – Q1, Q6
[] 2N3906 – Q5
[] 78L05 - U7
[] 78L09 – U2
[] V1 2K trimmer
Electrolytic caps:
[] 1 uF/25V – C24, C29, C33 – long lead is plus
[] 100 uF/16V – C16, C17, C25, C34, C38 – long lead is plus
Jacks:
[] 3.5 mm Jack – J3
[] Power jack – J2 -needs a lot of heat.
[] BNC jack – J1
Toroids:
Trim all the toroid leads to 3/8” and tin with solder before installing.
[] T1 – FT37-43 BLACK core – 5 turns wire pair.
Use 6” of both #26awg red and green magnet wire.
Use an ohmmeter to identify the common ends of the wires
and arrange them so that they are opposite each other as
shown.
The wires will now be in the proper positions for inserting into
the board.
[] L4 – T37-2 RED core – 18 turns of #26awg magnet wire
[] L5 – T37-2 RED core – 20 turns of #26awg magnet wire
[] L6 – FT37-43 BLACK core – 5 turns of #26awg magnet wire
[] J4,5 - sockets for the 1x3 pigtailed connectors.
 Both J4-speaker and J5-keyer are keyed connectors. Be sure to match the
keying slots for the plugs facing the right side of the board. This is
necessary for the correct color coding of the leads in the further
connections of the J4-external speaker and or J5-SKC Keyer.
This completes the bottom side assembly.

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Top side:
Only three parts to install now.
[] EC1 – encoder
[] V2 – volume pot
[] S1, S2 – SPDT slide switch.
Add a couple of temporary jumpers:
There are provisions for adding an optional ON/OFF switch and external
speaker/headphone jack. Until these options are installed, jumpers must be
installed so the board gets power and the speaker/mic speaker is connected.
Use a piece of resistor lead clipping to make the jumpers. These can be installed
on the display side of the board for easier access and future removal.
Speaker
Jumper
ON-O FF
Jumper

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Initial Power up:
Before you apply power to the circuits, spend a few moments to inspect your
work. Soldering issues are the most common cause of a kit not working first and
every time.
 Grounds take a little more heat than connections to tracks, so look at these
carefully to make sure the solder didn't just stick to the lead.
 Use an ohmmeter to check for continuity through the toroids. Not fully
stripping the magnet wire and making a good connection is a common
problem.
 If T1 is installed correctly there will be continuity between all four pads.
 Before any of the IC's are installed into their sockets, it's a good idea to
check to see if the voltage regulators are working correctly.
 Apply power to the board.
 Check for 9V – Pins 8 (+) and 4 (-) of the U3 socket is a good place to
check.
 Check for 5V – Pins 7 (+) and 8 (-) of U5 is a good place to check.
Good to Go?
Insert the MEGA328P processor into the 28 pin socket. Make sure it goes in the
correct way, although it will not be damaged if powered up in wrong way. (this is
not true of the other ICs)
 Plug in your supply (12 to 14V) and turn it on.
 If all is well, The display will read [ bn40P].
 If it didn’t, did you jumper the “On-Off” pads?
 The data for the selected band is now loaded, the default operating
frequency displayed and the board is now ready for additional testing.
 Remove power.
 You can now install the rest of the ICs.
▪ [] U1 – SA602
▪ [] U3 – LM358
▪ [] U6 - LM386
 Connect up your antenna
 Plug in the speaker/mic
 Turn power back on
 Turn the volume up and you should hear band noise. Tune around and find
some stations.
So far so good? If not jump to the trouble shooting guide, p16.

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Transmitter testing:
 The bias current for the linear PA needs to be set.
 You might as well connect up a power meter and dummy load now.
 Connect an ampmeter in series with your power supply. The 200 ma.
setting should be fine.
 Turn V1 fully counter clockwise.
 In DSB mode, key the transmitter and note the current.
 Adjust V1 until the current increases by 40-50 ma.
 If you don't have an ampmeter, set V1 to about the 2 O'clock position.
 If the current does not increase, you have a problem with the solder
connections on T2.
 Set the mode switch to the CW position.
 Key the transmitter and note the power output.
▪ 40M – ~5 watts.
 Switch back to DSB mode and check to see that you modulate when
speaking into the microphone by seeing power output on your meter.
 Your DSB PEP power will be about ½ the CW power due to the power being
split between the two side bands. Average power will be much less.
Calibration:
Now that everything is working, do the frequency calibration. Until this is done,
the actual frequency maybe (and most likely) off from the dial by up to 500 Hz.
There are two ways the LO can be calibrated.
1. Use a frequency counter. The LO signal is available at the test point labeled
“LO” on the top side of the board.
2. Zero beat a SWBC station. These are easy enough to find in the evening
and are on exact 5 kHz clicks.
Entering Calibration Mode:
 A 5 second push of the Encoder actives Calibration mode
 Release the Encoder when [CAL ] is displayed.
 The VFO reference oscillator can now be tuned with the encoder to calibrate
the frequency.
 This can be done in one of two ways.
1. Use a frequency counter at the LO test point.
◦ Tune to match the frequency which was on the display when CAL was
entered. To help you remember what frequency that is, the frequency
◦ will re-appear on the display, but leading with “C” to indicate you are
in CAL mode.

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2. Zero beat an AM SWBC station. To use a broadcast station, you need to first
tune it in, knowing they are on exact 5 kHz frequencies. Since you are
slightly off frequency, the audio will be wobbly. Active the Calibration mode
and tune the VFO until the wobble in the audio goes away. A scope will help
with this and get you closer then you can just by ear. You may not get the
frequencies to exactly match, but you can get pretty close.
Packaging the board:
A custom PCB enclosure is available from QRPGuys. Simple, light and with labeled
controls, it is a good option. If you don't mind doing some metal work, the board
will fit into a 110mm X 88 mm X 38 mm extruded aluminum box, which is
commonly available on ebay. A drill template is located at the end of the manual.
Operation:
The power up sequence is:
 The display will do a segment test by lighting all segments. [8.8.8.8.8.]
 The band for which the board operates on is displayed [ bnXX]
 The default operating frequency is displayed and the rig is ready to operate.
 The default tuning rate is 1 kHz.
Display:
The display reads out the operating frequency to 10 Hz. The MHz digits are not
shown and are implied by the band. Below 01.000.00, the leading zero is
suppressed.
 When tuned outside the Ham Band, the display will automatically shift to
indicate the MHz digits and the transmitter disabled.
◦ This reduces the display resolution to 1 kHz.
◦ The current tuning rate does not change.
◦ 10 and 100 Hz tuning rates are available, but the display will not
increment until the 1 kHz digit rolls over.
◦ The transmitter is disabled when tuned outside the Ham band. The side
tone will beep if you try to transmit.
◦ General coverage tuning is from 500 kHz to 30 MHz. Tuning outside the
Ham band will reduce sensitivity. Sensitivity will decrease the most when
tuning above the band due to the transmitter's Low Pass Filter. The
Receiver front end is only loosely tuned to the band so shows greater
sensitivity when tuned below the band.