Triplers for old tube sets
 

there is a thead over on ARF about using new flys on old sets. I wondered of a tripler could be used if just the HV tire is smoked.

For those who dont frequent ARF I figrued I would mention the results here for the equiring minds.

the set is a zenith roundie using a 6JS6 HOT. its completly functional, I did not disconnect the HV lead. I did connect a jumper from the HOT plate to the input of a TV tripler, then the HV prob to the anode lead from the tripler, and of course the grond clip to the chassis.

I get about 12kv from the tripler, that is with a functional HV tire still hooked up to the CRT (full raster). Not sure what would happen with out the load of the reg HV tire as far as output from the tripler.

anyway it seems like it may be an avenue to go down as the supply of FLYs dries up. I assume the tire is the most likely failure of old flys. clearly the mutlplication factor would need to be higher so the multiplyer would need to be made from discreet componets.

I guess I should have titled this thread "voltage multipliers for old tube sets".

I suppose with a little (or a lot) of engineering, you could build a power supply using a tripler or better yet, an integrated FBT/tripler such as has been used in TVs from the 80s & up. The old ECG-526 style triplers still required a flyback to input high voltage RF, and it came out as DC 26kv. If you use a later model integrated fbt, you might be able to make up an oscillator & driver circuit, copying a cheapie color TV, and feed that with a regulated 150-volt B+ line coming off some place in the TV. It would be a LOT of work, but it could also be used as a temporary sub in a CT-100, or other set where the FBT is about impossible to find.

The caveat is that the TV's own flyback still needs to be working to produce horizontal sweep, as to try to synchronize an external horizontal sweep circuit would be a project about like building the Panama Canal. At least if the original flyback is working but no longer needs to feed the HV to the tube, it might work.

Charles

...

How about the a modern HV switching mode supply thats in every microwave? Feed that into a trippler

That is what I was going for, the assumption being only the HV tire is bad. I have no need to pursue it now but was more just thinking out loud. I may on my next order to mouser check and see about getting some HV caps, 10kv should be more than enough for each leg of the multiplier. That and some 10kv diodes. I guess the real issue would be how large a capacitance value would be needed.

I wonder if, within the tube color TV world, the flybacks are similar enough electrically (impedance, transformation ratios, etc.) that a near-universal one could be built that only required shorting or opening various terminals/turns to adapt it to all the original circuits. Yes, there would be a lot of mechanical work required to make these connect to each chassis, but since most or all HV circuits are in cages, they would not be seen very easily, the same as putting new caps under the chassis of a TV as we do now.

I would think the biggest problem would be in the variations of the pulse windings.

hopefully the pulse windings could be transferred without too much difficulty, those are the windings that are on the bottom correct? I assume they would rarely be defective unless something real bad happened on say the convergence board.