In my days in the biz, Zeniths seemed to be fairly reliable but the pix didn't always offer a good color rendition of facial tones. RCA's could do very well but I think RCA was making up for lost time and money to recoup for the cost of color development that ran soooo over what was expected. Quality in production could have been better. Dumonts and Admirals had spectacular color but were less tollerant of differences in cameras and stations back then.
Today we fix, tweak, craft, rewire, scrounge, and sometimes talk to sets that were never reasonably expected to last 50 plus years.
We are Jug Heads! It's what we do.
