CTC-17 on Sacramento CL

[ctc17]

gkad you got it. mine has a great picture and the sound bumps. the cabinet is kinda botched. someone cut off the legs and in general abused it complete with cigarette burns. i got it off the curb so i cant complain.

had to replace the colorburst crystal and the filter in the amp.
be sure to adjust the cathode current. i have the instructions if u need theme

[freakaftr8]

Oh yeah I'm all over that cathode current. My other 17 runs a a nice 109 ma. Kinda low but I won't complain. I Cooked the CRT on 8v last night with my sencore and looks like the guns came up and holds in the green now. Still got a green raster and I swapped the demods. Yay a challenge! Lord knows I don't have enough of them already. Lol

[freakaftr8]

Well this is interesting, the focus was coming in and out rapidly and I checked for corrosion at the focus pin on the CRT.. Fixed that one but with the screen all green, I can turn down the green drive and max red and blue and get a sepia raster. I get 207v at green to CRT from the G amp. B and R amp (integrated in one circuit v20 tube) I get 20v should be 195v. If I pull the B/R Amp tube I get voltages restored and a nice greyscale raster! All tubes test good and no shorts. I went through and canned the bad tubes earlier. At pin 1 and 6 I get 240v (no load) on the B/R amp. Under load is 77v which should be 195v. Looking upstream and I do have a sams that my nose has been in all night.. But im kinda tired and think I might tackle the chassis this weekend.

Hope everyone is doing well, it's really nice to know such a friendly knowladgeable bunch and all you guys make this a great site! Im glad I know you guys

[joemama99]

You guys on the coasts run into the coolest stuff!Where I am at,all the retirees left their old sets up north and bought new when they came here.Nice find,shawn.

[freakaftr8]

Still having a heck of a time chasing down this chassis gremlin. The blue and red amp when the tube is pulled restores the raster to a good greyscale with proper voltages to the CRT.. With the tube in, the raster goes bright green, no blue or red and hardly any output voltage to the blue and red drive to pin 3 and 12 of the CRT. Pin 7 for green gets 175v like it should but Blue and Red reduced to 20v. Almost as something is shorting with the 6GU7 installed. The Green amp 6GU7 has no change installed or not. Tubes test good with no shorts and I tried swapping them already. Any ideas?

Thanks guys

[FredWesner]

Green screen, no control. Was a common problem on 16s and 17s. On the chroma board look for a wire on top of the PC board running near the 6GU7s. This wire will oxidize and break resulting in the severe green screen syndrome. We jumpered this wire under the PC board on any chassis that came in. Also resolder all of the PC board ground mounting stakes, intermittent stakes were also a common problem.

Hope this helps.

Fred

[sampson159]

he is right.there are actually two wires that oxidize and cause chroma issues.replace both.i have a 16 chassis that had the same issue and someone had replaced both wires but soldered to wrong circuit in chassis.bryan sent me a sams on this set and i easily traced it down and repaired.the first 3 days i about went insane trying to find the problem.good luck!

[freakaftr8]

Swee guys I'll check into this and repost! Thanks again!

Shawn

[freakaftr8]

Well you guys were dead on with the corroded wire! It was barely making a connection, I totally missed that one. Well I seem to barely have a blue drive. The CRT tests good on all 3 guns. Off the Blue amp max is 70v where should be 177v.
Thanks guys, at least I have somewhere to start now.

I really want to get this puppy up and running, im going to make it my bedroom set.

[freakaftr8]

Hey what do you guys suppose would cause a reduction in blue drive voltage to the CRT? If i pull the B/Y 6GU7, I have good blue drive voltage..
Thanks!