HELP with repair RCA TK-76
 

I am the proud owner of a TK 76 and have fired it up a couple times a year. Performance has been good and registration near perfect. Last year the viewfinder CRT fillament went bad due to a shorted cap in series. Then the VF viewfinder Vert sweep failed. This year when I fired it up W/O the viewfinder. The Pix is VERY dim and soft looking (like a bad vidicon in a CCTV camera). Is it possible all three plumicons are bad at the same time?, probably not but thats thats what this forum's about. Power supply volts at the P.S. pcb are right on but without a schematic I can't go much further.
I suspect the VF vertical problem is a bad chip on the front main PCB and the dim/ soft pictures a voltage missing there as well.
It's always my intention for my technical antiques to be functional as it adds to the joy of display and demonstrating. Help me keep this one alive a bit longer

Dave

I'm also trying to repair some NTSC TK76 cameras, have you had any luck with working out your problem?

My ones appear to have an issue with the main PSU board, and will not power up without making the transistor very hot and smoking, the other wont power up at all

I spent too much of my life around tube cameras...HL-77, HL-79, BVP-30 (I still own) and others and never saw all the plumbs go at once. For that matter, it was hard to kill them. They just sank to a noisy pix. Look elsewhere among the voltages.

Well i have managed to (with the help of a friend) get my two cameras working and giving images however it looks like you describe, very dull, murky and noisy...with a lot of lag and easily burning in...here is a video of how it looks.

http://www.youtube.com/watch?v=YRfcrkMnO6o

Turns out the tubes are rather tired, one of the cameras in particular when you cap the lense it looks like the "stars at night" (they even twinkle) not unlike dead pixels on a CCD camera.

Would anyone have some XQ1427 plumbicon tubes in their collection (i think thats the correct type?) I have plenty of vidicons and larger plumbicons. but not really any of the smaller ones like what were used in this camera.

Also could someone tell me what the type of lense mount the tk76 used? - it looks almost like a sony bayonet mount but slightly different. I am also seeking new lenses.

The viewfinders seem to give some trouble, i moved one the other day and heard zappy noises and it blew the fuse..