[Cure]

My beautifully restored FM-3 (by Bill Thomas himself!) stopped tuning stations. I turn it on and the "eye" lights up, but there is about a half inch of dark open space in the middle that doesn't even flicker when I turn the dial, in a major metropolitan area with lots of stations. And there is no sound! I'm hoping it's just a tube that needs replacing. Any ideas?
Thank you very much.

[mark funk]

I am no expert, but I do have five FM-3s (can you tell I am no expert, ever time a FM-3 would take a carp I would go and find an other one). I think that could be the tuning eye tube. But maybe someone who know more then my would have a better idea. I like to listen to the FM and it use to be a bumer when a FM-3s would take a crap. Before they all pasted away they did sound very nice. Hope you get it up and running.


                                                                                     

[Gvt1911]

Can you test tubes? First thing to do. Maybe find someone who can do this for you. Best place to start.

[rlee8394]

Cure,

Try gently pulling in and out on the tuning knob and see if you get any sound to pop on. I notice that I can make my FM-3 go dead quiet by doing this. I believe it is due to poor contact on some portions of the tuning capacitor C1. At least if you get sound again, you know it's not a tube issue. Hope this helps.

Ron

[Indiansprings]

Have you tried to contact Bill Thomas?

[Cure]

Yes, I have. Successfully. He thinks it's probably the 6AT8A tube that it is no good.

[Indiansprings]

Yes, I have. Successfully. He thinks it's probably the 6AT8A tube that it is no good.

I cant get a hold of him at all. He has my Preamp. He does awesome work. I sure hope I get it back from him.

[Cure]

UPDATE: Well, I ordered a new 6AT8A tube and with very high hopes, took out the old one and plugged it in. Sadly, no improvement. Any suggestions? Should I take all the tubes out and have them tested? Is it possible I got a bad tube? It came in the box and it lights up, but it's very old. The EMM801 looks like it is burned at the top, but I didn't think that was the problem.

[Cure]

UPDATE #2: Gvt1911's suggestion above turned out to be an excellent one. Pulled all the tubes out, had them tested and had 2 stone dead ones, including one of the 12AX7s. 3 of the others were too weak to reuse. When the bad tubes were replaced, it worked perfectly. Remarkable thing was that it was working at all before.

[baldrick]

Make sure you do a FULL realignment with the new tubes.  Otherwise it will not give you the best sound it could.I'd break the new tubes in for at least a week and then realign again.  Then it ought to stay pretty stable.