Hello Again,

I am was working on replacing the Flyback on my 55 Zenith. I am not sure if the old one works or not, but since I was able to find 2 NOS ones I figured why not.
Now the question is, Is it common for re-placment Flybacks to be smaller than the originals? The data sheet in the box with the new flys both confirm that at least according to my schematic, that they are the direct Zenith replacement. Its just that the Original look so much bulkier the that of the NOS. Otherwise the NOS looks like it will mount right up.


Thanks
Skip C

I am confused you are not sure if the old one works or not?

Rather than introduce a potential new problem (like a new fly that could be installed incorrectly or have some other reason why it may or may not work out) why not get the set up to the point that allows you to determine the old fly is bad, and then replace it with the new one. You could even replace the old working one with the new one if you just like the idea of a new flyback, but at least you would have one last possible problem to contend with.

My thinking is do as little restoration as possible for a safe trial run (that includes cleaning and other disassembly) and give it a test run. This of course means making sure you don't have any shorted caps that would kill it, there are ways for a safe start up. And I WOULD replace any paper cap in sight as they are almost always bad, but other than that you can be asking for trouble with wholesale changes if you have not yet based line run it to see where you are and what needs to be repaired IMHO.

If you haven't recapped the set then you're wasting your time replacing the Fly.

As for your original question, yes, they often appear different than the originals, they often don't perform as well either in terms of horizontal linearity so you are definitely better off using the original if you can.

If you have no High Voltage the most common suspect if the Horizontal Oscillator not running, recapping the area around that tube will often bring it back to life, assuming the Power Supply is working halfway decently.

There are a few good sized cracks in the wax tire, around the fly, and some hairline cracks in the anode wire. Should I just replace the Anode wire?

get the set working, if the fly is bad then replace the fly, if the fly is ok and there is corona or arcing then replace the anode wire. The less you disturb it now the better you will know if its a problem or not.

I'd say just replace the anode wire at this point. Cracks in flyback wax don't really prove the flyback is bad.
Completely re cap, replace electrolytics, first. The flyback may be fine.
Bill Cahill

examples of a flyback that works fine

I believe "anode wire" might be a misnomer. The anode wire connects to the 2nd anode connection of the CRT.
Do you mean the flyback wire and connector to the plate of the 1B3?