Zenith Horizontal Efficiency Coil

[iong]

Anyway to substitute horizontal efficiency in Zenith roundie 25CM33 Mine is falling apart and fly is too hot to touch after 2 hours.
Perry

[Electronic M]

Sam's should list subs. If it doesn't and you have a parts set with the same plastic form that ISN'T destroyed you could unwind the wire from the donor form and the Lin coil and transfer the Lin coil wire to the new form.

[iong]

It has 3 leads so i'm not sure if it's rewindable. Sam lists no subs.
Perry

[JohnCT]

Originally Posted by iong

It has 3 leads so i'm not sure if it's rewindable. Sam lists no subs.
Perry

Not sure on the Zeniths, but I seem to recall the RCAs used a three pin setup for PC mounting stability but had just two connections.

John

[oldtvman]

should be a Zenith number on the part, I did have a couple of those, but I'd have to have the part#

[old_coot88]

Wonder if eff coils were the same inductance value across different brands (e.g., Zenith, RCA, RCA clones etc.). If so, and provided it's tunable for the resonant dip, a different-brand coil oughta work OK with an innovative mounting scheme.

[iong]

The Zenith Horz, Eff. coil shows to be taped (1ohm)on the schematic which is the reason for the 3 leads. I broke out the stuck core files the inside and inserted same size core. I got the current with-in spec. The fly still gets hot enough to smell the wax after 2 hours. Changed HV. Reg tube and still the same. Line voltage is 117. Don't know what's wrong.
Thank you for any help,
Perry

[Electronic M]

If it has a focus tube pull it out and replace with a 6KV diode (or 3 2KV in series). If you can find a SS HV rect that will help too. Removing filament winding load from a flyback usually cools them well....

Check your HV too if it is low pull the shunt rect cap and see if it gets normal or high if it does that then the regulator circuit has a problem and is overloading the HV winding... which will cause over heat.

My 29JC20 tends to run hot after mitigation of it's issues so I leave the top door open for ventilation cooling.

[iong]

Thank you Tom. TV is now running with 6.3KV diode. I noticed there a 2.7m half watt resistor on the focus pot instead of 1watt. This TV a friend found at a flee market and loved it and ask me to repair so I don't know history. CRT is not fantastic but OK. Almost almost all the tubes were week and few were Zenith. Output tube, Reg tube, and Rect tube were bad. TV now playing OK.

[iong]

Thank you Oldtvman. Got old coil together and was able to adjust.
Perry