Dumont RA103 - Videokarma.org TV - Video

Gregb · #1 08-22-2014, 08:12 AM

I picked up a really nice condition RA103 and on checking the CRT the filament is open.

Tried resoldering the lead wires with no luck. From what I have read it would seem the original CRT is a little hard to find so what have you fellow RA103 owners used for a replacement and what changes if any were needed?
Also if anyone has a spare they are willing to part please let me know.

Thanks

Gregb

kramden66 · #2 08-22-2014, 10:54 AM

a 12LP4 will work but the neck is a little longer and would touch the back and you would have to change the anode end , i'm sure there are other 12" crts that would fit but the numbers aren't coming to mind, i hae a 12QP4 laying arround but it is so weak that my friends beltron really couldn't help it.

baursam · #3 08-22-2014, 10:55 AM

try El Predicta on here, he has a lot of tubes and I would be surprised if he didnt have one. I am pretty sure that is where I got mine.

Gregb · #4 08-22-2014, 12:47 PM

Thanks guys, I will look into both suggestions. I am really looking forward to getting this one working. It is the earliest set I have and it looks really cool!

Gregb

Boobtubeman · #5 08-22-2014, 08:15 PM

Doesnt stellartv have some too???

SR

Tubejunke · #6 08-22-2014, 09:07 PM

What is the correct c.r.t. so anyone who may have one will know?

tvdude1 · #7 08-22-2014, 09:36 PM

Quote:

Originally Posted by Tubejunke

What is the correct c.r.t. so anyone who may have one will know?

They use a 12jp4

Gregb · #8 08-22-2014, 10:53 PM

Yes, sorry, 12QP4 or 12JP4 is what shows in my Dumont manual.

Gregb

baursam · #9 08-23-2014, 01:51 AM

I have the aluminized version 12KP4 in mine, right length, brighter picture, no ion trap. 12LP4 is slightly longer, and works fine, but back must be removed. Stellar TV does have 12LP4 s I believe. 12JP4 is very hard to find, at least when I was looking.

tvdude1 · #10 08-23-2014, 05:57 AM

Find a 12kp4 its shorter .

Gregb · #11 08-23-2014, 08:37 AM

OK, 12KP4 seems to be the way to go. Anyone have one they can part with?
Thanks

Gregb

Tim · #12 08-24-2014, 01:09 PM

This Sylvania chart posted on the ETF site lists several other subs and the differences from the original. 12RP4 is a close sub but they are rare. The chart even shows larger size tubes that are electrically compatible for use when increasing CRT size.

http://www.earlytelevision.org/pdf/c...nce_manual.pdf