Quote:
Originally Posted by Penthode
I restored a CTC5 Whitby a decade ago. One issue was low high voltage. It would minimally make about 21kV. The shunt regulator drew next to no current.
I discussed this on the forum and it seems a common problem. I could not find anything amiss in the horizontal seep circuit. To help boost the HV to get it to the point the 6BK4 would do its job, I substituted for the HV rectifier a solid state plug in replacement.They regularly pop up on eBay.
I had problems with maintaining vertical sweep linearity and ended up replacing all the capacitors and many of tyhe resistors in the vertical sweep circuit.
|
I also have a Whitby and have not yet moved it and started any evaluation.
I do recommend also placing a 12 meg resistor from 6BK4 cathode to CRT cathode supply, plus a 1 K resistor in series with cathode to measure regulator current using a voltmeter. (1 volt drop across 1,000 ohms = 1 ma.) This was done with CTC15 and later models to improve HV regulation. I performed this on two CTC11 with improvement (noticeable during scene changes) to maintain brightness and focus.