Hi,
I am just starting out on trying to fault trace older valve radios. To this end I purchased a working Kriesler 11-99 set. I have just finished building a signal tracer and tested it on the 11-99. To my immediate surprise it worked perfectly on the later stage of the radio but I got nothing from the first valve output. I think the problem is that the tracer I have built resolves AF only but I am not sure.
The tracer was built from a circuit supplied by Elliott Sound Products. It was Project 164 and I built the optional attenuator version. I tried to include the schematic here but cannot work out how to do that. Could someone please take a peek at that circuit and advise me if in fact it is only capable of resolving AF and not RF. And if so would it be easy to alter it to include RF. Of course the more likely scenario is that I am doing something wrong but knowing if the tracer is OK for RF is a good starting point. Any help would be most appreciated.

Ray
This device is for audio frequencies, and won't work on RF as it is.
Commercially made tracers were available back in the day and I'm pretty sure had an untuned diode probe for RF.
Silicon Chip magazine had an article on making a tracer, and had details on how to make a diode probe for it. It was the June 2015 issue and you never know, the PCB for it may still be available.
Harold

Thanks for confirming my suspicions Harold. I will look for the article you suggested and have a crack at making an RF probe. Cheers Ray.

And I bet your 11/99 is working, anyway!

I don't think I've ever seen one that doesn't.

Did you know that the 11/99 was the last valve mantle radio in production anywhere in the world?

Yes Ian I bought a working set on purpose in order to familiarise myself with where in the circuit I should hear a signal and where I cannot. Now that I know the tracer I built does not work for RF I will fix that (hopefully)and get used to probing the 11-99. After that I will look for a tube radio repair project. So far I have only built low voltage radios and have never repaired anything. The thought of logically working through a circuit in the hope of pinpointing a problem seems like a challenging way to kill a few hours in the shed. I am reading up on the safety aspects of working on 240 volt radios so that time is the only thing I kill in the shed. Cheers Ray.