Travis,
Sounds as if you are mastering removal/replacement. Recall that I said that from the voltage measurements you gave that it was not possible to tell whether the problem was Q5 or Q4. I would replace Q4 next and check the voltages again. It could be that Q2 is not working right though the BE voltage is normal. If replacing Q4 doesn't fix things I would replace Q2 next.
The voltages you reported for Q1, Q2, and Q3 are well within normal range (except for Q2 collector) so I don't think these are damaged. If replacing Q4 brings the voltages back into the normal range then you can worry about the trimmer. The key indicator of success is when the Q4/Q5 emitter voltage goes to about 2 volts.
The setting of the trimmer won't affect the DC voltages, only the RF output. If the voltages are still abnormal something else is wrong.
Don't be discouraged that the first thing you tried didn't fix it. Keep going and it will work. Let me know what happens with a new Q4.
Neil
Neil,
I Changed out Q4, and It helped out. The Carrier is as strong as It used to be, and I set the voltage at about 14 volts on the trimmer. When the controls are set to normal, the audio is present, but distorted. What may be causing this to happen?
Travis
Travis,
Sound like progress to me! The next step is to measure the terminal voltages again and compare them to the expected values.
The audio is applied to the final stage through R16 into the base of Q3 thence to Q2 and then to the emitters of Q4 and Q5. Before condemning these components, do the voltage check.
Also be aware that my experience with this transmitter has shown that an improper antenna load can cause the audio to be distorted. According to my information, this transmitter "expects" to see a load of about 800 ohms resistive. If you are testing with a wire antenna, are you doing so with R18 installed? My transmitter audio was terrible on bench test with R18 removed but cleaned up to perfection with it installed.
You are now in a difficult phase of troubleshooting unless the voltage checks turn up something. I don't recommend a shotgun replacement of all the transistors until you have more data.
Neil