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-   -   1955 Motorola 17T20 (http://www.videokarma.org/showthread.php?t=270460)

dieseljeep 05-19-2018 08:31 PM

Quote:

Originally Posted by maxhifi (Post 3199763)
Looks really nice, I look forward to seeing how it works!

It looks like the 25L6 went to air!
That tube furnishes the lower voltage to many of the signal circuits. If it is bad, you'll have to replace it before going any further.

LADR 05-22-2018 01:07 PM

Why in the world did Motorola put the tuner tubes under the chassis?? Seems stupid to me.

Electronic M 05-22-2018 02:58 PM

Quote:

Originally Posted by LADR (Post 3199873)
Why in the world did Motorola put the tuner tubes under the chassis?? Seems stupid to me.

Some Motos keep the fly and 1B3 under chassis with an access door. Dumont used to put 6AL5 detector tubes and 6X4 rects under chassis in some of their RA-103 sets...There are probably more bad examples in the TV field but at least they were socketed...In the tube hearing aid era, the subminiature types they used (pencil diameterX1.5" long) were often soldered directly into the chassis. :eek::D

^Yet another attack from boring-trivia-man, AKA me. :D

LADR 05-22-2018 07:23 PM

Quote:

Originally Posted by dieseljeep (Post 3199785)
It looks like the 25L6 went to air!
That tube furnishes the lower voltage to many of the signal circuits. If it is bad, you'll have to replace it before going any further.

It didn’t, it was just dirty. Don’t know what the white stuff is.

LADR 05-23-2018 07:16 PM

1 Attachment(s)
I’m starting to paint the cabinet and i think its turning out nice!

dieseljeep 05-27-2018 11:12 AM

Quote:

Originally Posted by Electronic M (Post 3199874)
Some Motos keep the fly and 1B3 under chassis with an access door. Dumont used to put 6AL5 detector tubes and 6X4 rects under chassis in some of their RA-103 sets...There are probably more bad examples in the TV field but at least they were socketed...In the tube hearing aid era, the subminiature types they used (pencil diameterX1.5" long) were often soldered directly into the chassis. :eek::D

^Yet another attack from boring-trivia-man, AKA me. :D

That was the last Motorola that the chassis had to be removed to replace the tuner and high voltage rectifier. The slightly newer larger screen sets had the tuner on the right side with the tubes on top of the chassis. The HV rectifier had the trap door. UHF equipped sets had the 6AF4 under the chassis, but there was an access cover on the bottom.
Then there was the Sylvanias that had the solder-in 5642 HV rectifiers. IIRC, the tube location chart didn't even list them. :sigh:


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