Yes AKA fly1

then I should prob try to get one, just in case, though my FBT seems to be working fine and OK, that low resistance i saw on the main coil is worrisome.

And I got one! not in my paws yet, but I will soon have a ram xo-36 FBT. :banana:

only question is, do I keep running on the old one, and wait for it to fail?
the one with the oddly low main winding at 95(ish) ohms that all schematics say SHOULD be 180 ohms, but seems to be working OK for now, or go ahead and stick the new one in? :o

How about measuring the new one before doing anything rash?

Well I have found that nos flybacks compaired with original old ones will almost always vary as far as ohms readings. And if your set works fine I myself would leave it alone until you really need to put the new one in. And that 95-180 ohms difference don't seem right, are you sure the schematic is correct and did you lift wires off the flyback befor checking.

Every schematic shows exactly the same thing, be it SAMs, FADA, or RCA,Riders or whatever.

https://imgur.com/x1izfje


between point 1 and 2 ( 2 being the HOT plate cap removed ) is 180 ohms, and from 2 to 3 ( HOT plate cap to cap of hv rect, ) 240 ohms. I did get 240 ohms from 2-3, but not 180 from 1-2 .

the other windings 4-5-6 also checked OK according to the schematic.

I will probably just leave the old one in until it fails ( when/if it ever does ), cause if it lets go, I don't think it will hurt anything, cause there is already a ¼ amp fuse built into damper power line to keep things from catching on fire. :o

But did you check the flyback with the soldered wires removed. And if the flyback takes a dump I doubt anything will turn into fire, but you will loose hv.

Wild guess .... perhaps the early transformers were wound with the same size wire from 1-3 and just tapped at 2, while later models used slightly larger wire between 1 and 2 to better handle the dc plate current of the horizontal output tube. :scratch2:

jr

I had it completely out of the set at one point when checking it,
https://imgur.com/qw1tylZ
https://imgur.com/VQodl6R

I covered it up with super corona dope as best as I could and stuck it back in, made no diff in the resistance :/

interesting thought, hey you never know what they did and after all thordarson always claimed that there flybacks were exact improved replacements. So the thought of using a different gauge wire on a given coil within the flyback to handle higher voltages could be possible but of course the amount of turns would be different for a different gauge wire being thinner or heavier just as long as the ohms were correct for that coil.

Actually, it is the amount of turns that matters to determine voltage, not the wire gauge. The gauge just determines the max current handling capability. The DC resistance measurements given on schematics for transformers are for troubleshooting purposes. A larger gauge wire will have less resistance but less resistance usually means there are shorted turns.

All true, exactly Tim.

so now I'm just waiting for the NOS flyback to come and i will see how it compares to the original

That will work. Either way if your set works ok , if I were you I would just hold on to the new one until you really need it. After all these flybacks eventually will be gone so whatever time you get with the old fly take advantage of it, even if the ohms are not the same.