Yes Barry, I feel badly that I did not take photos to document that whole
LPF-TR board removal process. I would normally do that but was too heavily
involved in the trouble shooting process and not sure at the time where it
was leading.
I did however make some notes and drawings at the time while I was
disassembling the Band Switch in order to get the LPF-TR board out of the
chassis. If you want I could try to scan and submit those.
I must admit, I am not great with navigating and posting with online user
groups. Can you give me an email address that I should send .jpg or .pdf
files to in order to have them posted?
While trouble shooting my problem I also discovered some changes on the
LPF-TR board regarding biasing resistors for the PIN diodes. I bought my
Corsair II new from a dealer at the Dayton Hamfest so presumably these
changes were done at the TEN TEC factory. I recall reading somewhere about
improvements to performance in PIN diode biasing, however I did not make
these changes to my Corsair and so can only presume they were made at the
factory but not documented by TEN TEC on the schematic.
Regardless of who did the modification, here is what I found on the LPF-TR
board in my radio:
1. 470 ohm resistors were installed in series with D1 and D2
2. R3 had been changed from 330 ohms to a 100 ohm resistor
3. R6 had been changed from 150 ohms to a 47ohm resistor.
It was a bit discouraging to find that the more details I looked into, the
more discrepancies I found with the schematics in my manual. Having said
that, I still love my Corsair II and will not likely ever part with it.
Accordingly, I have kept careful notes on every modification or repair ever
made to my Corsair in the 28 years that I have owned it.
73,
Rick VE3ORY
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