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On April 27, 2020 at 3:22 PM n4buq <n4buq@...> wrote:


I have a 334A whose AUTO function is not working correctly. It seeks an initial null then drifts well off of that null.

I've been checking the voltages and waveforms on the A5 board and have bound TP5 is completely dead. I've checked everything I can think of so far and still haven't found it; however, in my exploration of that board, I found some components that don't appear to be on either of the schematics I have and not sure what they are. There are a few of them and in two cases, they're tied from collector to base for two of the transistors.

I'm attempting to attach pictures that show these parts but if that fails, I'll add these to an album. If they do come through, I'm talking about the darker brown components that look a bit like a resistor but are marked a bit differently (e.g. red black black orange brown. My presumption that is 200,000 with the brown being a tolerance or tempco indicator but don't know.

Anyone recognize these?

BTW, the serial number prefix for mine is 1140A and one of the manuals I have is valid for the serial number; however, I'm not sure if there may be some Service Notes that may have included those parts. I have a lot of microfiche and the index for the 334A mentions quite a few updates that are not part of a manual (at least I don't think they are). Unfortunately, the only microfiche I have is a 1972 version so it's quite a bit older than mine.

Thanks,
Barry - N4BUQ