4SQRP Bayou Jumper 40 Meter CW Transceiver, Assembly & Instruction Manual

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revised 3 Feb 2021 Bayou Jumper revB Assembly Manual page 25 of 46
this case, install C31, the 22p capacitor, and re-test.
Re-check the receiver calibration.
It’s a good idea to do a final check with the
radio installed into its box, but before screwing down the panel.
When the receiver calibration is satisfactory, to fix the turns in place, paint the
toroid with a light coating of clear fingernail polish.
Finally, secure the panel to the box’s wood posts with the four #6 sheet metal
screws. Be careful not to overtighten them, which could strip the threads you’re
cutting into the pre-drilled wood posts.
Troubleshooting
If your Bayou Jumper does not operate after assembly, repeat the visual
inspection of solder joints. Especially inspect the leads of L1 for good solder
connections. Compare the component placement diagram with the instructions
to be certain that all components were installed in their correct locations. In
particular, be sure that C20 and C4 have not been interchanged, which would
make to tuning range too high in the band. C20 should be 120 pF and C4
should be 100 pF.
A check of voltages at strategic locations on the board while under power can
serve to isolate problems to a particular circuit. The table on the next page lists
nominal voltages for the unit in receive and with the regeneration control fully
counterclockwise
. If an entry is marked 'XXX' do not attempt to measure it .
The XXX voltages are high impedance RF points where a DC reading will
possibly be erroneous due to the high RF voltage present, or the stray
capacitance of the voltmeter probe could cause the circuit to misbehave.
For those who may be experiencing the charm of a regenerative receiver for the
first time, there are a series of MP3 audio files posted on the Bayou Jumper
Yahoo Group, in the Files area. These give examples of what the receiver
should sound like under various tuning conditions. The file names explain to
what you are listening.