CTC16 Flyback Cooling

[Electronic M]

Originally Posted by Findm-Keepm

They do run warm, but if you have melting/dripping wax, one of three problems come to mind:

1. Too much cathode current through the 6JE6/6LQ6 - should be less than 250mA, preferably the lowest the efficiency (linearity) coil will adjust to.

2. The horizontal drive signal is mis-shapen. Caps, out of tolerance resistors, or a weak 6CG7/6FQ7 can cause the "on" time to increase, which ups the current through the fly.

3. Too much load on the fly - bad/wrong boost rectifier (it requires a "fast" rectifier for Boosted B+, a typical silicon diode won't do), bad focus rectifier (my CTC16 has an R-2AV2 silicon replacement, eliminating the focus rectifier filament load from the fly), and even a shorted turn or two in the focus coil can increase the focus current, but still yield good focus range. You can also eliminate the filament load from the 3A3C by using a R-3A3/ECG508 silicon replacement.

Also, make sure the B+ is the correct level - today's higher line voltages increase all the voltages in vintage sets. A dropping resistor add (complicated) or running on a variac (easiest - set it for 110 VAC and you should be good) are suggested as fixes.

Cheers,

It is running slightly less than 200mA, on the 6LQ6. I have not checked parts in the horizontal osc/drive system (aside from the 6CG7 which is quite strong) or the waveform. Don't know if my boost rect is silicon or what, I'd have to check that.....If it ain't then the only way I can put a 'fast' diode in is if I happen to have one in the parts I've scrapped off BPC sets. I don't stock any other new diodes that can take the voltage and current, and I don't buy parts online. I don't have any SS 3A3 or 2AV2 substitutes either.

AC at the outlet the set plugs into here with it on is 117VAC. I will look for a high line voltage primary tap on the transformer.

My thoughts on adding a fan are that one should add a Heppa filter in the air intake to limit dust intake.