I'm working on the final touches of this nice little Emerson 702B, a typical AA5:
http://www.nostalgiaair.org/PagesByModel/717/M0004717.pdf

Everything is actually playing beautifully ... and I have fully re-capped and replaced EVERY resistor.. and after the output transformer failed... even that is new.

I've even re-coned the speaker !! ...

It's like jacking up the tuning cap and slipping a whole new radio under it now!!...lol

Well... now I have a new and curious thing happening.
... maybe some of you have encountered this.... so before I strain my little brain... thought I'd ask yooze guys.

After the radio is well warmed up.... when I turn off the power ... as soon as the switch clicks off... the speaker emits a loud bird-chirp.

I tried a different 50L6 and it does the same thing.

Any ideas?

CHEAP PARTS? SORRY I COULDN'T RESIST
BLIP

:I'm working on the final touches of this nice little Emerson 702B, a typical AA5:
:http://www.nostalgiaair.org/PagesByModel/717/M0004717.pdf
:
:Everything is actually playing beautifully ... and I have fully re-capped and replaced EVERY resistor.. and after the output transformer failed... even that is new.
:
:I've even re-coned the speaker !! ...
:
:It's like jacking up the tuning cap and slipping a whole new radio under it now!!...lol
:
:Well... now I have a new and curious thing happening.
:... maybe some of you have encountered this.... so before I strain my little brain... thought I'd ask yooze guys.
:
:After the radio is well warmed up.... when I turn off the power ... as soon as the switch clicks off... the speaker emits a loud bird-chirp.
:
:I tried a different 50L6 and it does the same thing.
:
:Any ideas?

Are the characteristics of the new output transformer the same as the old one? I am thinking that if different, maybe C6 value needs to be adjusted?

:I'm working on the final touches of this nice little Emerson 702B, a typical AA5:
:http://www.nostalgiaair.org/PagesByModel/717/M0004717.pdf
:
:Everything is actually playing beautifully ... and I have fully re-capped and replaced EVERY resistor.. and after the output transformer failed... even that is new.
:
:I've even re-coned the speaker !! ...
:
:It's like jacking up the tuning cap and slipping a whole new radio under it now!!...lol
:
:Well... now I have a new and curious thing happening.
:... maybe some of you have encountered this.... so before I strain my little brain... thought I'd ask yooze guys.
:
:After the radio is well warmed up.... when I turn off the power ... as soon as the switch clicks off... the speaker emits a loud bird-chirp.
:
:I tried a different 50L6 and it does the same thing.
:
:Any ideas?

A long time ago I built a small guitar amplifier with all AA5 tubes, and mostly used it to listen to cassette tapes. It sounded quite nice. It was built on a wooden chassis, though, and had no shielding. It would chirp whenever it was turned off. Seeing as there was no shielding, and that the wiring may have well been a bird's nest, it's understandable why chirping noises were heard.

Shield grid and plate wires, and keep those wires of one stage away from the same in another.

T.

:A long time ago I built a small guitar amplifier with all AA5 tubes, and mostly used it to listen to cassette tapes. It sounded quite nice. It was built on a wooden chassis, though, and had no shielding. It would chirp whenever it was turned off. Seeing as there was no shielding, and that the wiring may have well been a bird's nest, it's understandable why chirping noises were heard.
:
:Shield grid and plate wires, and keep those wires of one stage away from the same in another.
:
:T.

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Got a VARIAC? betcha if yopu lower the AC to about 85 Volts, Tweety will sing full time, and you can find where he is hiding.
Lewis