mitaux8030
Silent Key
I've dug out the old Uniden HR2510 and getting it back on air again after about 5 years in storage.
After replacing a dried out electrolytic cap that had shorted a +8 volt rail to the PLL & synthesiser stages, I've given it a full alignment and in the process discovered that the frequency stability is awful... the frequency jumps about within a +/- 500 Hz window without any apparently predictable behaviour.
Though, I found that by touching crystal X301 (10.2417 MHz) the problem can provoked a fair bit... and so I've earthed the crystal casing, and viola! No more instability problems. Thought this might help others trying to keep this old radio going.
After replacing a dried out electrolytic cap that had shorted a +8 volt rail to the PLL & synthesiser stages, I've given it a full alignment and in the process discovered that the frequency stability is awful... the frequency jumps about within a +/- 500 Hz window without any apparently predictable behaviour.
Though, I found that by touching crystal X301 (10.2417 MHz) the problem can provoked a fair bit... and so I've earthed the crystal casing, and viola! No more instability problems. Thought this might help others trying to keep this old radio going.