? Prewar DuMont flyback on eBay ?
 

I see this potted transformer on eBay, claiming to be a DuMont flyback... I have no experience on DuMont prewar sets, and I've never seen a cylindrical potted flyback. And I think all the prewar sets (other than small-screen kits) have direct step-up HV supplies. So is this a horizontal output transformer mis-labeled as an FBT? A high voltage transformer? Or just a plain misprint? Might be a rare item!

Charles
http://cgi.ebay.com/NOS-DUMONT-TV-TE...QQcmdZViewItem

It is for the 1946-47 RA-101. It is a flyback.

All prewar sets except for the German E1 had transformer HV supplies.

http://www.earlytelevision.org/e1.html

The E1 was by far the most advanced prewar set, using a low tube count, flyback HV, and a rectangular CRT.

No kidding... I have an RA-101 and I didn't recognize it! I'll have to look at the schematic again on that set... I thought it was a standard HV transformer step-up from the mains supply like the prewar sets, as you say. I might be wrong on my terminology. I was thinking that in order for it to be a flyback, it had to do both jobs of Horizontal Output and also HV supply.

Charles

You may be right about the transformer. I'm out of town and can't look at my sets, and it may be that it goes in the RA-102 instead. It is a horizontal output transformer, but I can't recall if it also provides high voltage.

That transformer was used in both the 101 and 102 chassis.

Steve

It's the horizontal output transformer for the 101 "A" version (60 cycle HV). It might be used in the 102 also, but I really don't want to pull the front panel off my 102 to look.


Chuck

Yes, it is the Horizontal Output transformer used in the RA-102 to drive the H deflection coils. The HV though is generated by a separate pulse transformer with its own oscillator triggered by H sync.