The Family DuMont

[CaryLee]

Originally Posted by bandersen

Yes, you will get FM reception in both FM and TV positions and the CRT filament is lit at all times.
The only thing that happens in FM mode is that the CRT brightness is cut off. All the TV circuits are still running including the high voltage.
So you really are wearing out the TV tubes and CRT while just listening to the radio.

Thanks! Now I understand how it works, and now that the CRT is lit up, I see it's working just as you describe.

Now I'm no engineer, but "I am a thinker"..and it sure seems DuMont could have come up with a better setup than to have to power the entire TV, and wear out ALL the tubes (including CRT!) just to listen to the radio!

I've read of folks putting a circuit into their old radios with "eye tubes" that shuts off the eye tube a few seconds after tuning stops. I guess certain German radios did this right from the factory. With radio "eye tubes" getting scarce and expensive, I've thought about it for my '38 RCA console. I've read that useful life of a radio "eye tube", 6U5, 6E5, and the like, is around 1000 hours. Not very long if you listen to the radio a lot!

Just dreaming out loud here (figuratively speaking..errr...typing), but I wonder how hard it would be to unobtrusively install some sort of cutoff that kills the TV circuit..particularly CRT, when listening to the radio. TV tubes, in general, are plentiful and cheap..but CRT's sure aint!