1950 RCA 16" 6T65 (KCS47 chassis) repairs and alignment

[Adam]

Here's some pictures of the chassis.

I still have to get some screws for the HV cage, and I'm missing that back piece of it. But it shouldn't be hard to make something to fit that. Does anyone know how the original HV lead connects? This set was missing it. When I was testing this before, I just used a piece of HV wire with alligator clips on each end, but I'd like something better to stick in there permanently. I'm really not even sure where it originally hooked to the crt.

[Adam]

There's still some buzzing in the sound if there's lots of white in the picture or writing on the screen. I can adjust the primary of the discriminator trans to eliminate the buzzing in those circumstances, but then the sound gets softer. This might be the best I can get it. It seems to me if I just modify that tv/phono switch so it doesn't turn off the picture I could hook the audio in directly, other than that which seems sort of like cheating, I might be stuck.

It also gets some visible retrace lines when the picture gets dark.

Also I'm getting vertical lines on the left side of the screen, really only visible in a plain white picture, I drew an arrow on the pic to where one line's most visible, where the edge of the couch gets wavy. Seems like a horiz problem, adjusting the horiz linearity coil affects it, but doesn't fix it.

And I need to clean behind the glass in front of the crt, it looks like I have to remove the crt to get to it.

I want to fix that horizontal trouble now, but as far as things like the buzzing, It seems to me that I could just keep fussing with this tv and making minor improvements for a long time, but these older sets just can't be made to perform as well as the sets from the late 50s and 60s, no matter how much you fuss with them.

(And that bright spot in the middle of the picture is because I just put my finger over the flash and some of the light got through)

[Phil Nelson]

Originally Posted by Adam

as far as things like the buzzing, It seems to me that I could just keep fussing with this tv and making minor improvements for a long time

Buzzing in very high contrast scenes is pretty unavoidable with some old sets. If it's any consolation, I have a newer plasma TV that buzzes if it displays an extreme image like big white movie credits against pure black.

With every TV project, I end up accepting some little compromise. You reach a point where you recognize that fiddling is making things slightly different, but not perfect. So you decide which flavor of "different" you like better, and move on to the next project.

It's impressive that you learned alignment in the course of one restoration.

Phil

[John Folsom]

Phil is right, some of these vintage sets just did not perform as well as other designs of the same vintage. I think it safe to say that the KCS-47 chassis was not RCA's proudest moment.