rca21d645
01-13-2021, 09:09 AM
I am restoring an Admiral 12X12 television and after a few days of trying figure out why there was no vertical deflection, I figured out that the issue is the vertical output transformer. The part numbers for the transformer are as follows:
Admiral: 79B24-1
Stancor: A-8112
Merit: A-3036
Chicago: TSO-5
Thordarson: 26S51
If anyone has a vertical output transformer that they are willing to sell I would greatly appreciate it.
rca21d645
01-13-2021, 11:31 AM
Here's a photo of what I'm getting on the tube. Audio comes through though, albeit a little weakly. I tested the height and linearity pots, replaced all the paper caps in the vertical, and tested each resistor and replaced the ones out of spec. I'm 99% sure the transformer is what's causing the issue as I also didn't get the proper values when testing it with my ohm meter. I also swapped the 12AU7 tube (which tested as good) with another good 12AU7 and that changed nothing.
Kevin Kuehn
01-13-2021, 11:35 AM
I am restoring an Admiral 12X12 television and after a few days of trying figure out why there was no vertical deflection, I figured out that the issue is the vertical output transformer. The part numbers for the transformer are as follows:
Admiral: 79B24-1
Stancor: A-8112
Merit: A-3036
Chicago: TSO-5
Thordarson: 26S51
If anyone has a vertical output transformer that they are willing to sell I would greatly appreciate it.
I have an original on a parts chassis that I just measured as good. PM me if interested.
Kevin Kuehn
01-13-2021, 11:39 AM
Here's a photo of what I'm getting on the tube. Audio comes through though, albeit a little weakly. I tested the height and linearity pots, replaced all the paper caps in the vertical, and tested each resistor and replaced the ones out of spec. I'm 99% sure the transformer is what's causing the issue as I also didn't get the proper values when testing it with my ohm meter. I also swapped the 12AU7 tube (which tested as good) with another good 12AU7 and that changed nothing.
What resistance readings did you measure on primary and secondary?
rca21d645
01-13-2021, 11:45 AM
What resistance readings did you measure on primary and secondary?
The secondary measured as 36 ohms and the primary wouldn't measure at all, like it was open.
Kevin Kuehn
01-13-2021, 11:59 AM
The secondary measured as 36 ohms and the primary wouldn't measure at all, like it was open.
OK an open primary is always bad.
Kevin Kuehn
01-13-2021, 12:08 PM
Here's a picture of the transformer I have. It is a 20Z1 chassis. Can't make out the part # in the bright light but it is correct.
https://live.staticflickr.com/65535/50831522238_e50baaaa80_z.jpg
rca21d645
01-13-2021, 12:15 PM
Here's a picture of the transformer I have. It is a 20Z1 chassis. Can't make out the part # in the bright light but it is correct.
https://live.staticflickr.com/65535/50831522238_e50baaaa80_z.jpg
yep, that looks just like the one I have.