This is first pix of my 21CT55 using a repaired CTC20 FBT. Note that the VTVM shows full scale reading on 30 range with 1000 divider at the crt anode or 30,000 volt range. The VOM shows 200 on the 500ma range or 200ma current at the HV .5amp fuze which is the same as measured at the horz output cathode. This indicates the CTC20 FBT circuit is more efficient than the original 21CT55!
This pix was taken 1/2/2016, over 5 years after the original FBT failure.
Presently the 21CT55 is inoperative since the repaired CTC20 FBT failed due to arcing of the repaired silicone covering. Not to worry, I've got an extra CTC 20 FBT in it's original RCA box. All I got to do is make wire to wire switchover from old to new FBT, what could be simpler, eh??
b!00000119 by
Tom Schnerk, on Flickr