wrote...
Ok--I solved the problem with the radio!
Yes, it had been modified. Someone grounded pin 10 of the PPL chip and
fiddled with the VCO for above-band operation. I removed the jumper on
pin 10 and then used a frequency counter to realign the VCO.
Realign the VCO using a DMM, rather than a frequency counter.
Use the frequency counter when aligning the crystal oscillators.
As it had clearly been got at, I would take the time to check the frequency of each crystal
oscillator and the carrier balance. Depending on which version of Cobra 148GTL you have, there
could be a few crystals.
Even more important, check the output and drive bias settings. If these are not set correctly,
the transistors may not last long.
Regards,
Peter.
http://www.citizensband.radiouk.com/