Rca ctc-5

[DaveWM]

while checking on brightness level I checked the cathode and grid voltages at the CRT. I don't have my VTVM handy, but the green grid was maxed out at 240v while the schematic has it a 255, the cathode voltages were much closer.
I don't know if the load of the DMM is more than a VTVM, but I may just check that 1 meg resistor that feeds the B+ to bias the grid thru the background pots. I would think that I should be able to hit the 255 at something less than max setting, as opposed to the max of 240v. the other drive controls seem to have no problem getting the the correct bias setting. While I am able to get good gray scale, its at a reduced brightness. Later I plan to install my CRT test socket so I can see where the G2 voltages are (they are not easy to get at like the cathode and G1). I am pretty sure I should get a brighter pic, the CRT test fine, and the HV is solid at 22.5 kv, I know the early CRTs were not as bright as later but I would at least like to see how it looks when the voltages are closer to what is in the schematic.