Best Tube to eliminate RFI

While not the world's most technically adept guy, I can't see how any tubes could be causing your problem; they're only amplifying a signal, and this isn't microphonics from your description. Bob bundus' suggestions are a good place to start; perhaps switching speaker cable leads could tell you if perhaps one of them is acting as an antenna? I had an Audio Matiere amp in my home for audition once and had a similar problem I couldn't solve with line conditioners, Versa Woodblocks, ferrites or the like; one friend of mine thought it could be a grounding problem within the amp, but since it wasn't mine I didn't follow up on that one. You might ask your Jolida dealer about that, though. Good luck!

Lloyd Walker makes a kit that includes metal wrap and ground wires to place around miniature tubes that eliminate RF and microphonics.

This of course, assuming the radio signal is being picked up by small signal tubes and not through your interconnects or electrical system.

If these are 9 pin miniature tubes, there are also military RF shields that slip over the tube. The best ones include heat sink design.

I have a Walker kit that I bought some time back that I might consider letting you try. It does appear to be quite a bit of work to install, probably the reason I have not experimented with it.

The slip on RF shields would be the easy experiment, and I believe that BWS tube services has these in stock.

Here is his link: http://www.bws-tube.com/

here's hoping that future radio broadcasts be limited to your tuner.

Interesting, Albert, as I've never had a tube pick up RF--glad I saw your post, guess I've been lucky. Keithcady, do you have separate small signal tubes for each channel, perhaps if not in the preamp section maybe the amplifier section (I'm not familiar with the Jolida's circuit)? If so, switching them could probably tell you if the tube is causing the problem.

I have had tubes pick up RF in only one situation. However I suppose there must be some instances where it happens or the military would not have manufactured RF shields in such great numbers.

In any case, the shields I purchased were about $5.00 each, and helped to damp microphonics as well as pulling away heat. Pretty cheap experiment for Keithcady even if it fails.

Many suggestions posted here are valid and should be tried as well. Perhaps I misunderstood Keith, it sounded like he had tried various tubes, which improved the rejection of the RF.

When the solution is found I hope the results are posted. Good info for future reference what ever the source of the problem.

Thank you Albert, I've tried everything else. Made my own shielded and grounded power cord. Changed speaker wires and interconnects. In fact disconnected all of the interconnects from the system and the RF is still there. So the pick up is either in the amp or tubes. I tried the bws site but I haven't heard anything. I've e-mailed them I would be interested in knowing more about your Lloyd Walker product.