The finals are replaced and tested! 110 watts out!
So I started looking over things. One thing I’ve been looking into is the zero beat. It seems to me that when you push the button, it should emit the CW tone. I can get it to emit the tone, but only after pressing the zero beat button many times.
I also don’t like the CW tone. It seems odd even when at the correct frequency. I hooked up the audio output to my oscilloscope and saw the audio output… It looks…er…interesting.
I think I was expecting to see more of a sine wave as opposed to a sawtooth (I guess) wave.
There is one minor little problem – it appears the antenna isn’t properly connected to the receive part of the circuit, because it can’t hear anything. It does transmit on the correct frequency (per my antenna analyzer), so the problem is likely minor as opposed to something going bad related to the frequency or mixer.
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2 Responses to Ten Tec Repair Day 3
Well done, Andrew.
For my receive “guesses,” make sure RY1 on the SWR-TR board energizes on transmit. There’s a couple of diodes to check on that board that clamp whatever RF might get into the receiver. PIN diodes commonly fail as RF switches, so check the MPN3404’s on the RF attenuator board. Otherwise, follow your troubleshooting. 😉
Russ, you rock. 🙂 I’ll look into it this weekend.