Phonola

[hermitcrab]

Well I am back working on the phonola... it works great except the FM stereo light does what it wants ... when you first turn the set on and the tubes are warming up the FM indicator will light up... then as the set warms up the light goes out never to light again...the voltages seem to be correct , this all operates off of a 6M11 compactron tube , which my tube tester will not accept. The stereo is working as you can hear the separation when you switch from regular FM to Stereo FM... I have no clue what voltages are required to light a NE-2 bulb ... when it is warming up the voltages on the indicator are around 150 volts , but drops to the working voltage of 90 volts where it does nothing... could the NE2 just be worn out?... can they wear out? I would share a schematic if I could ....

[electra225]

I have a Motorola with that condition. Antenna strength, i.e. signal strength has a bearing on the stereo light performance.

[Dr. Radio]

Well I am back working on the phonola... it works great except the FM stereo light does what it wants ... when you first turn the set on and the tubes are warming up the FM indicator will light up... then as the set warms up the light goes out never to light again...the voltages seem to be correct , this all operates off of a 6M11 compactron tube , which my tube tester will not accept. The stereo is working as you can hear the separation when you switch from regular FM to Stereo FM... I have no clue what voltages are required to light a NE-2 bulb ... when it is warming up the voltages on the indicator are around 150 volts , but drops to the working voltage of 90 volts where it does nothing... could the NE2 just be worn out?... can they wear out? I would share a schematic if I could ....

Didn't you post this same question on the Antique Radio Forum?

If you did, post a link. I'll nab the schematic you posted and post it here.

If that wasn't you, my apologies. Just seemed very familiar.

[hermitcrab]

Yes it was me , I ask on all forums , as someone out there might have dealt with a problem like this ...

[Dr. Radio]

I found your post, and "snipped" the section of the circuit in question from your .pdf. Click on it to enlarge/clarify it....

[hermitcrab]

As I stated on the ARF when I shut off the shop light , and scroll through the dial the FM stereo light will flicker but nothing more, the antenna is about is good as it can be , the front end is hot , as I am picking up stations I usually don't get... I am beginning to think someone twiddled with the coils , everything is correct on voltages, the resistors all checked for drift , My only conclusion is either the coils need tweaked or the 6M11 is weak...

[William]

I too have one with the same condition. It's my Motorola B1000 stereo table radio. Sometimes the stereo light works, and sometimes NOPE!

Bill

[TC Chris]

I've got a Technics stereo receiver out in the shop with a stereo light (and switching) that went from intermittent to MIA. i had inquired somewhere and somebody suggested checking the stereo threshold pot. As with other pots, it can get dirty and intermittent.

The receiver is buried under the cassette and CD players in a high skinny cabinet so I have not actually extracted it for fiddling. Mono is good enough in the shop. But keep that possibility in mind.

Chris Campbell

[Firedome]

Most Compactrons are super cheap, for 3 or 4 bucks I'd try that.
My Scott tuner has one, and wish more had been used in audio, but GE introduced Compactrons just about when tubes were being phased out of audio, however their current low prices are a gift to vintage TV restorers!