Zenith mayflower chassis 28F22 no horz oscillation - coil/transformer problem

[kramden66]

no horz oscillation ... it all traces to the the Horz. Osc.-AFO Trans , how the heck do i repair this or replace it ? - that's the horz freq and horz phase controls or coils , how is it a transformer ? i'm just a little confused with that but the part going to the 6AL5 is open , i think it is the primary but don't have the schematic in front of me to say for sure but it is open.... i can't just put another coil in can i ?

Mike

[Eric H]

You can possibly sub one from another make if you have to, at least for testing purposes.
It should be possible to find a new replacement also.

Looking at the schematics I would guess one from any early RCA 630 based set would work fine.


Sometimes a break in a coil will be near the lug where the wire connects to the outside, you might be able to pull the cover off the coil and repair it.

[kramden66]

Eric
they are covered in wax , everything is in wax on that little board , ive tried the method of baring the wire where it is just coming out of the coil and even then it still is open ... i guess like you said put a simular coil in from another set , if i have one that is simular i will be happy to try it but will have to look , plus fighting to get the starter of my car out leaves little time for anything.

mike

[Eric H]

I remember that board on mine, I didn't realize the H-Osc transformer was embedded in it!

The RCA coil should work if you can wire it in.
I don't know if you saw the picture of my Flyback transplant but I've attached a picture of it.

All the tubes in the Horiz are the same on the RCA and the Zenith so I see no good reason the Fly and Coil won't work just fine.

These have a tremendous picture once they are running!

[Eric H]

Since I can't find my chassis pictures can you post a picture of your transformer?
I have one from an RCA, just wondered if it was physically similar?

[kramden66]

Eric
Yes i saw your fly pictures and someone on here actually found a RAM flyback that replaces several zenith flys and the original number in the sams and the number on the one in mine match so it isn't an issue , Yes your set does look fantastic.... The coils/transformer is very simular to the rca 630 or 8ts30 but i don't have either set to borrow from , i think if i had the two or atleast one from the rca that might do the trick , i will post looking for one , do you have one ? , as far as a picture goes i could try but it would be easier to just email it .

Mike

[kramden66]

Here is how they compare , zeinth primary 67 ohms , rca primary 37 ohms , zenith secondary 58 ohms tap @ 15 ohms , rca secondary 35 ohms tap @ 9.5 ohms .... i think it would work but would need the rca parts to try it , i also looked at the schematics and would think it would work , it might need the 150mmf changed to 82mmf like in the rca or some other tweak or it may just work period , atleast thats what i see.

Mike

[Eric H]

Here's what I have, this is from an RCA of some type, probably a 630.

[kramden66]

Eric
Zenith version has two mounted side by side on a little board , i suppose this could be adapted or the primary coil removed and put into the zenith.

I need to email you a picture of the zenith version because i don't really know how to do the photo uploads , my email is [email protected]

mike

[kramden66]

Eric
measure the resistance on it if you can , see if you get primary 37 ohms , secondary 35 ohms tap @ 9.5 ohms , the only way to do anything with the zenith is to get the wax off but even then theres no clue as to where the break is , could be deep in the winding and that would be a complete waste of time unless it is rewound, i have a couple RCA T-100 xhassis and can't really use parts from it , i have 2 untouched chassis to the 6T74 or whatever that model is , it is just like the one Bill Cahill struggled with for a long time and the parts there i don't think would work, thing is the rca and zenith ones have center taps , the others that have simular coils do not.

mike