Hi John. Thanks for the reply.
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First of all, I replaced the A23 as the input Divider on the old one was damaged.? Burnt SMT resistors, and I don't know what else.? it has always not been right since I got the instrument years ago. For sure someone transmitted into it 100W when it was set to the RX test mode.??
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The replacement was from a good 8920A.? I never expected that the Firmware in the PROM would be different if the A23 was from another 8920A.? However, I am not an expert on these so I will do what you suggested and take it apart and repair the damage I find, and install it again and run the diags.??
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Yes that would be the A2 Audio Analyzer board.? Sorry for the incorrect terminology. I will run the tests again on it and report back the exact failures.
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I will do a 12dB SiNAD test today and see if this is my error. I just don't recall ever seeing it pinned before I started replacing Audio Boards etc.
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The Output Assembly will also get tested again. That failure (Output Assembly Low) was from the DIAGS.
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This instrument sits on my bench 100% of the time.? Once warmed up it is pretty accurate therefore the reason for installing the High Stab unit.? It never goes in the field.?
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I primarily service Amateur Radio Equipment and it works well for me.??
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Thanks for your help, I will be back in a few days with some results.
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Ronnie
VE3NLS
