converting a huntron tracker

[m3vuv]

hi all i have a huntron tracker with a u/s mains transformer,most of the voltages i can find with an old transfo from a cro,except the crt eht,would it be possible to use a tft display with it?,just seems too good to bin and chances of geting a replacement transformer are just about zero!.

[mikerj]

Is the primary or secondary bad?  If it's a conventional E type core with separate primary and secondary you could try unwinding the O/C winding, carefully counting turns until you find the fault and then either repair the break or re-wind with suitable enamel wire.    It might even be a built in thermal fuse which are usually fairly accessible after removing some of the outer insulation.  I've successfully repaired a couple of old scope transformers like this, time consuming but not that difficult.

[CaptDon]

Why wouldn't an old CRO transformer have the EHT winding? all of the older EICO, HEATHKIT, HICKOK and so forth using tubes like the 5UP1 or 5DEP31 and such all had one transformer with filament, B+, CRT filament and CRT EHT windings. You could use a small 2.5Kohm to 8 ohm audio transformer driving the 8 ohm side with a mosfet and a narrow pulse width signal at about 1Khz and rectify (with fast diodes) the 2.5Kohm winding. Should give you about 1KV. Those old CRO transformers are big, never going to fit into a tracker. The D.C. supply to the audio transformer supply idea should be around 12vdc. basically you are creating a simple flyback circuit. The load on the secondary will limit the flyback spike on the mosfet to around 200vp but you need a really fast pull down on the mosfet gate to get as much inductive kick as possible.

 

[m3vuv]

the primary got nicked with an angle grinder(long story),i have an old tek scope transfo but i need 300+volt for a voltage doubler,the acceleration voltage is speced at 1350v,i tried getting that but the most i could get was 600v,that was using a cockcroft walton multiplyer,thats what made me think of a tft pannel,guesse thats a vector type tho?,its something i dont know anything about tbh.