QRPKits KD1JV, Instruction Manual, Page: 19 / 22

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NOTE: When entering the Calibration mode, the default frequency values for reference and IF offset are loaded.
This is done in case the values now stored in EEPROM become corrupted. Therefore, it is not possible to “test”
the calibration by re-entering the calibration mode. If you wish to test the calibration, measure the transmit
frequency on the highest band you have chosen to install into the rig, before and after calibration.
If you were able to set the BFO trimmer, everything up to the 1 st mixer is working correctly. You can now connect up an
antenna (or signal generator) and peak the receiver input trimmer caps for each band. Peak for band noise or signal
strength. The receiver will be quite deaf until the trimmers are properly peaked.
Transmitter testing:
1. Remove power supply from board.
2. Insert the 74AC02 into U4 socket
3. Install L7. You will need to remove the board from the case to do this.
4. Connect power meter and dummy load to antenna jack.
5. Plug a straight key into the paddle jack or close the Dash paddle when turning on power so transmitter can be
keyed on and off.
6. Check power output on all three bands. Using a 13.8 volt supply, the power output should be about 5 watts.
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Power output can be tweaked to some extent by changing the spacing of the turns on the low pass filter cores.
With a little experimentation, it should be possible to achieve 5 watts output on each band.
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Coils L8, L10 and L12 will have the most effect on power output. These are the inductors which follow
the PA FETS, and influence the matching between the PA and load. When the turns on L8. L10 and L12
are most evenly spaced around the core, this will result in the maximum power output. Moving the turns
closer together will reduce power output.
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The inductors L9, L11 and L13 also have some effect on power output. These work opposite of the input
side inductors, moving the turns closer together reduces power output.
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If you have little or no power output and can not peak the receiver input with the trimmer caps, you
probably have the wires from the band selector switch to the relays reversed and have the wrong filters
selected for that band. Pretty easy to get it wrong.
Volume tweaks:
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If you use an external speaker instead of headphones most of the time, you might find the maximum volume a
little low. The maximum audio level is set by the AGC circuit. Removing R19 (220K) will eliminate the bias on the
base of Q4, resulting in requiring a higher audio level before AGC action kicks in.
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