[Tubejunke]

I have looked at a few Webpages relating to these old signal tracers and so many have popped up with missing RF probes that people build them. It's not like I'm dealing with some extremely difficult circuit. Most any unit can have a probe made out of a couple of resistors, a detector diode, and a low value capacitor.

My confusion mainly stems from not really knowing the nature of the instrument, but it's quite obvious that something is wrong if I have to disconnect the center conductor of the probe to get fairly normal, or dare I say reasonable performance out of the thing. So once again what I am doing is loosening the amphenol connector until the center conductor is backed away. So all the noise is much quieter and I am able to trace signals using the gain as needed. If I screw the connector in the noise is just awful and the gain must stay almost all the way down. Strangely what this amounts to is the probe working with only the shielded side of the circuit connected. That really doesn't make sense electrically.