Okay........,
I could not find a TR23; however, I did find a W23 which looks like a bigger version of the two that are bolted onto that metal "wall" in the back corner.
With the radio upside-down, control knobs facing me, this W23 is located on the right-hand side, just ahead of the mounting bracket screw-hole, and about 1-1/4" in from the side.
Although this W23 has the metal mounting "plate" with bolt-hole, it is not bolted to anything.
This is how I checked voltage at W23: radio ON, DVM on 20v (or less) DC setting, black/ground cable clipped to the radio's grounded metal perimeter, touching each prong of W23 with the red cable probe.
Before I keyed the mike, the voltage reading at any of the three points would begin at around 9.5 to 10 and immediately start falling, with no definite voltage reading, as it constantly was dropping.
Once I had keyed the mike, readings were more stable.
The B pin held pretty steady at 6.28 whether the mike was keyed or not.
The C pin no mike keyed was 9.09; mike keyed was 8.33.
The E pin no mike keyed was 8.17; mike keyed was 7.61
Did I test the right thing and did I do the test right ?
Another thing I noticed when I had my ear very close to the radio: with the radio ON, as it would be for receiving, there is the faintest constant "ssshhhhhhh" coming from the speaker; I key the mike and it goes silent; release the mike and there is the little blip of static and the faint "sssshhhhhh" returns; this is so quiet that I just barely hear it.
Should I obtain some de-soldering wick before I proceed with the other tests ?
Thanks.
