Rca ctc-5

[old_tv_nut]

Originally Posted by Penthode

... Also to regulate, the 6BK4 does not sense current, it senses voltage. The boost B+ voltage is sensed which should be directly proportional to the HV.

You are correct - don't know what I was looking at before.

[DaveWM]

I also found the vectorscope useful for touching up the matrix balance pot on the back of the chassis as well. this pot varies the cathode bias resistance of demodulator tubes. the effect on the vector scope is to squash down the circle pattern to get it as round as possible. I found that by adjusting the top core of the CW driver trans and the matix pot at the same time was the best way to setup the matrix.