With an antenna connected, there should be a noticeable increase in background
noise (hiss or static) as the preselector control is tuned. With the frequency dial set
to 200, the 3.5, 7.0 and 14.0 bands should peak with the preselector pointer at
approximately the 12 o’clock position. The 21 and 28/29 frequency bands should
peak with the pointer around the 2 o’clock position. Depending on band conditions,
you should also be able to hear signals.
c.2.2. Unit Receives On Some Bands But Not Others
If the unit receives on some bands, but not others (particularly if not on one or more
10 meter bands) check that the heterodyne oscillator for that band is running.
It is possible that one or more sections of the bandswitch are dirty and not making
connection. See if rocking the bandswitch from side to side has any effect.
It is possible that the driver grid or plate slug-tuned coil is bad for a specific band
c.3. Transmitter Troubleshooting
Perform the Transmit Tuning procedure described on page 27. If the Transmit tuning
procedure does not work, here are some tips that might help.
Does the unit receive properly? If so, the Driver Grid and Plate tuned circuits,
heterodyne and carrier oscillators and LMO, and IF circuits are working. Assuming the
receiver is working, check that the following tubes are fully seated:
V5, the 1st Transmit mixer tube (6EA8)
The 6CB6 (2
nd
Transmit mixer) and 6CL6 (Driver) tubes on the driver board (these
are the ones with the shields)
General Troubleshooting Tips revised 12/17/2021 Page 27
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