Sylvania 1-076 arrived!

[jeyurkon]

Originally Posted by John Folsom

John,

Thats fantastic! Way to go. You may find the ringing is better when you swap the yoke leads, as often the yoke has a balancing capacitor across one of the two horizontal windings.

The Y10F25 yoke is speced at 25mH (H), 50mH (V), 27 ohms (H) and 60ohms (v). RAM does not list a replacement for the 241-0002 (flyback transformer, not a choke)

Thordarson, Stancor and Merit do not list a replacement. Must be an oddball flyback...?

The Thordarson cross ref. lists the 1-108 chassis as using a 113-0010 flyback, with a HVO-50 replacement. Is this a mistake in the Thordarson listing?

I was wondering about whether the balancing capacitor would do that, but it goes against my grain to think that a one-port passive network would behave that way. There must be enough stray capacitance to make another connection, turning it into a two-port. It does seem to behave as you said though. At least the original one did so I hope this one does too.

Thordarson didn't exactly make a mistake. The RF HV supplied sets don't fit neatly into the charts of Thordarson, RAM, and Merit. The 113-0010 is the RF HV transformer and is listed for the Horizontal output in the Merit catalogue also, even though that's not what it is.

I wouldn't call the 241-0002 a flyback because it doesn't use the retrace (flyback) to generate the HV. It looks just like a filament or audio transformer. All four of the manuals that I have for this set call it a choke, including the SAMS. I assuming that they have a reason to call it that. It hurts my head to think about that part of the schematic.

If you want to peruse the service manual you can see it at:
https://www.msu.edu/~yurkon/Sylvania_9-2_Sup1.pdf

Thanks for pointing out the 113-0010 being called a flyback. I now have cross-reference numbers to search for a spare.

John