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DuMont RA-112 TV: Next Project
#14

First power up as a TV (not just FM audio) and it works!

Tonight I powered it up with the HV enabled and with a test picture tube. After some tweaking there was a decent picture with not so decent sound. That needs looking into, even FM radio isn't great. But it was the first time I tested the whole thing. My TV knowledgeable friend was over for the spectacle for advice an moral. Fortunately nothing went terribly wrong. Failure is always an option, just not a good one.

It turns out the "snapping" was due to arcing when B+ was hit its peak on power up before dropping to its "normal" value. It went away after some lead dressing in the area. I still need to understand it a bit better and possibly place sleeving on some of the wires in the area.

I found the location of the arcing by turning off the lights and taking a video with my phone during powering up. It was pretty obvious without 300W of lighting beating down on it.

I still need a replacement speaker. I'll look for one at Kutztown in the morning...

It still needs some work, but it seems to be 90% there.

The biggest problem was finding a signal source. My VCR's were both messed up. I think they have belt problems. The DVD players don't have RF outputs. I ended up running a cable across the basement from our CTV splitter and using the one analog decoder box we have.

   

Can't think of anything witty.
Greg O.
Whitehall, PA


Messages In This Thread
DuMont RA-112 TV: Next Project - by Greg - 10-07-2021, 10:53 PM
RE: DuMont RA-112 TV: Next Project - by GarySP - 10-08-2021, 10:10 AM
RE: DuMont RA-112 TV: Next Project - by Greg - 10-08-2021, 12:34 PM
RE: DuMont RA-112 TV: Next Project - by MrFixr55 - 11-08-2021, 03:00 PM
RE: DuMont RA-112 TV: Next Project - by radiorich - 11-08-2021, 07:56 PM
RE: DuMont RA-112 TV: Next Project - by Greg - 03-04-2022, 11:39 PM
RE: DuMont RA-112 TV: Next Project - by Greg - 05-05-2022, 09:02 AM
RE: DuMont RA-112 TV: Next Project - by radiorich - 05-05-2022, 09:21 AM
RE: DuMont RA-112 TV: Next Project - by Greg - 05-05-2022, 09:29 PM
RE: DuMont RA-112 TV: Next Project - by TV MAN - 05-06-2022, 10:21 AM
RE: DuMont RA-112 TV: Next Project - by Greg - 05-12-2022, 10:52 PM



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