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You wouldn't necessarily see a voltage, it's when you keyed, the voltage would drop to zero at that part of the CB/PA switch (if you could get to it to check). IF Pin 3 works and TR33 turns on per TR32 Then D38 would show a voltage on both sides of the diode - because it's powering the "Mute" function of the Audio Amp Chip - that indicates the TX transistor was working - No TX lite would mean more of a blown trace to one side, - which you reference a bad PLL because the trace that goes to the TX lite - powers the Varactor and tells the PLL "I'm TX'ing"- so in light of all that has been said - each possibility needs to be checked - no matter how frivolous it may seem at the time because they are all potential routes and if checks aren't done - the radio still doesn't work...

In PA - the RX get's "SQUELCHED" when you ground Pin 3 when you key the mic . Diode D44 upsets the apple cart of IC1 M5223 - 1/2 of it anyways. - it conducts to ground and kills, Squelches, receive - so then the Volume control is free to take in what comes out of TR30 - the Mic amp that goes to the AM regulator, it sees the audio - and tries to send it - but it never transmits - no signal to turn on the bases of the TX line (TX power).

<blockquote data-quote="Handy Andy" data-source="post: 632612" data-attributes="member: 52309">You wouldn&#039;t necessarily see a voltage, it&#039;s when you keyed, the voltage would drop to zero at that part of the CB/PA switch (if you could get to it to check). IF Pin 3 works and TR33 turns on per TR32&nbsp; Then D38 would show a voltage on both sides of the diode - because it&#039;s powering the &quot;Mute&quot; function of the Audio Amp Chip - that indicates the TX transistor was working - No TX lite would mean more of a blown trace to one side, - which you reference a bad PLL because the trace that goes to the TX lite - powers the Varactor and tells the PLL &quot;I&#039;m TX&#039;ing&quot;- so in light of all that has been said - each possibility needs to be checked - no matter how frivolous it may seem at the time because they are all potential routes and if checks aren&#039;t done - the radio still doesn&#039;t work...In PA - the RX get&#039;s &quot;SQUELCHED&quot; when you ground Pin 3 when you key the mic . Diode D44 upsets the apple cart of IC1 M5223 - 1/2 of it anyways. - it conducts to ground and kills, Squelches, receive - so then the Volume control is free to take in what comes out of TR30 - the Mic amp that goes to the AM regulator, it sees the audio - and tries to send it - but it never transmits - no signal to turn on the bases of the TX line (TX power).</blockquote>

[QUOTE="Handy Andy, post: 632612, member: 52309"] You wouldn't necessarily see a voltage, it's when you keyed, the voltage would drop to zero at that part of the CB/PA switch (if you could get to it to check). IF Pin 3 works and TR33 turns on per TR32 Then D38 would show a voltage on both sides of the diode - because it's powering the "Mute" function of the Audio Amp Chip - that indicates the TX transistor was working - No TX lite would mean more of a blown trace to one side, - which you reference a bad PLL because the trace that goes to the TX lite - powers the Varactor and tells the PLL "I'm TX'ing"- so in light of all that has been said - each possibility needs to be checked - no matter how frivolous it may seem at the time because they are all potential routes and if checks aren't done - the radio still doesn't work... In PA - the RX get's "SQUELCHED" when you ground Pin 3 when you key the mic . Diode D44 upsets the apple cart of IC1 M5223 - 1/2 of it anyways. - it conducts to ground and kills, Squelches, receive - so then the Volume control is free to take in what comes out of TR30 - the Mic amp that goes to the AM regulator, it sees the audio - and tries to send it - but it never transmits - no signal to turn on the bases of the TX line (TX power). [/QUOTE]

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