Hi Folks,
I got my 20 m QRP transceiver kit ready recently. RX seems to be OK and the
same with TX when I test it with 50 ohms dummy load. Output is 3 - 4 W
depending on the supply voltage. All controls and adjustments function
normally. Output waveform is fine when seen with 60 MHz scope.
Problems start when I connect it to my multiband Butternut vertical antenna
(SWR abt 1:1.4) and press the key. TX starts to oscillate wildly, ouput
waveform goes "hazy" indicating spurious components, high pitched noise in
the headphones, enormous clicks etc. L12 and L13 have some taming effect
but not much. I tried with antenna tuner but the results are quite
confusing: oscillating almost all the time.
Before starting to mess with the dense circuit board I would like to ask
you QRP kit owners about your experiencies. Is 1320 normally neurotic about
it's load, is this behavior normal and you must have a very accurately
tuned load ? Is there any "off the shelf" typical cure for 1320 ? Have you
any suggestions how to tame this beast, ferrite beads, RFCs, suppressing
resistors etc. ?
Your comments and experiencies are most welcome so I can start to look for
the solution from the right direction and not to distroy the circuit board
unnecessarily.
I read this mail area frequently but if you prefer to answer to my private
address, it is:
matti.niskanen@yle.fi
Thank you and 73
Matt OH2CF
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