I was given a stash of radios and this one has a rx issue. EPT3600-14B. Single bipolar final. It does TX fine, on frequency and with good modulation. But, tp3 is reading zilch on rx and reading the channel frequency on TX, not the expected vco frequency. That's got me bugged. I did find the tp3 side of L18 opened, and the vco buffer does have the expected frequency running, pll locked and PD output as expected.
I'm thinking the rf attenuator diodes D15/D16 may be shot, along with maybe tr17 and or tr18, maybe shorted and letting the TX channel frequency bleed back to tp3 thru the rx front end. That's as far as I got before bedtime and I'm sitting at the DR office thinking on it rn, wondering if that could even work. Someone has been in this radio with the usual crap, clipped diodes, resistors and questionable soldering. I will yank the suspects out when I get home, any ideas?
I'm thinking the rf attenuator diodes D15/D16 may be shot, along with maybe tr17 and or tr18, maybe shorted and letting the TX channel frequency bleed back to tp3 thru the rx front end. That's as far as I got before bedtime and I'm sitting at the DR office thinking on it rn, wondering if that could even work. Someone has been in this radio with the usual crap, clipped diodes, resistors and questionable soldering. I will yank the suspects out when I get home, any ideas?
