SyncroGuide tannin my hide!

[6GH8cowboy]

electrolytics have been bridged, cathode volts go away when pulled. I can tease more than a half inch arc off the HV rect plate with an insulated driver. Still a vertical line up the screen and yes the yoke is properly level and the vertical hold moves bumps up or down the line. Cathode curent is very low at the HO tube and hdrive is over 50v PP. Freq still seems high. 6SN7 subd, All parts replaced in h osc ckt, trimmer caps have some effect but no where near enough. I even lifted the doorknob cap to verify it wasn't breaking down under voltage. I am suspecting an unortodox failure in the HO transformer due to the fact I have enough drive to light the rectifier but not result in any sweep. Resistance measurments seem very close but we all know how that goes. I subed the yoke on the bench but the H drive remained the same on the scope. I suspect that the HO trans is somehow significant to the H osc freq via feedback somehow. I still need the expertise thats out there I don't know how to post the schematic for the 20Y1 Admiral.

[teevee]

Try this: Disconnect 1 lead from the horizontal section of the yoke. Now, measure the resistance from that lead, to the point it was hooked up to. You should read a low resistance. (thru the yoke and part of the HOT winding) I suspect you will find an open.

[6GH8cowboy]

There is .47 cap in series with the yoke. the resistance at yoke is about 15 ohms and the resistance of the trans is about 11 ohms seems good to me. If i jump the cap, the line moves to the left a bit so I believe the yoke is good at present. The cap provides DC isolation for centering purposes. I still suspect the transformer; but is is so strange to be able to provide enough fillament and voltage (albeit low) to the HV rect to give a light on the screen. Lifted the width coil to check the readings while I was at it.

[Zenith26kc20]

If you have a VTVM I would check across the wires going to the horizontal section of the yoke where they attach under the chassis. I would be hesitant to use a digital meter as they can be damaged too easily by the RF. There should be some AC (high frequency) across the wires. It sounds like an open in the yoke circuit to me. That set will give high voltage with the horizontal yoke circuit open, just not alot. The yoke is actually across pins 4 and 5 of the flyback with the yoke coupling in series with pin 5. Also, with the yoke disconnected and the coupling cap jumpered, do you get a fairly low resistance across the wires going to the flyback. Sorry if I may have repeated ideas but just thinking out loud.

[teevee]

So, to be perfectly clear, with everything hooked up, (and the set off) you measure 26 Ohms across the .47? (right at the .47)