About to start on something rather unique and interesting...

[VintagePC]

Originally Posted by Phil Nelson

Funny how all of those 6SA7s were bad. They look identical. Perhaps the Tung-Sol quality control person had a hangover that day.

If they're all bad in the same way, I'd be tempted to wonder if the original builder got a hold of some factory rejects for cheap - tubes that still perform but don't meet the full specs. Since this is a custom built set (and knowing a few people that like to hack together their own stuff), it might well be that the set will operate properly with those "bad" tubes that are out of official spec... but still in-spec enough for that design. I wouldn't bin them just yet

[Glenz75]

Yeah I've wondered this too, and I will probably put all those weak 6SA7's back in after its all fixed and see what happens. I checked all the tubes before fault finding so wanted to rule them out first and finding all those weaks ones I just had to change them

Originally Posted by VintagePC

If they're all bad in the same way, I'd be tempted to wonder if the original builder got a hold of some factory rejects for cheap - tubes that still perform but don't meet the full specs. Since this is a custom built set (and knowing a few people that like to hack together their own stuff), it might well be that the set will operate properly with those "bad" tubes that are out of official spec... but still in-spec enough for that design. I wouldn't bin them just yet

[Pielock373]

Congrats on the progress you have made with the picture on this set

Steve

[Glenz75]

Thanks Steve Its still a long way off from being done, but yeah the progress so far has been positive. By the way your RCA Projection TV is just awesome!

Cheers
Glen.

Originally Posted by Pielock373

Congrats on the progress you have made with the picture on this set

Steve

[Glenz75]

Progress Update - One section has been totally recapped and most of the resistors have been replaced. Some checked fine, others were way off.
The area I did was in the horizontal drive/osc/sync section. The horizontal sync is now stable and the picture locks in perfectly.
I have to admit that some of those old components were a little tricky to get out, some of the caps were buried underneath others, thankfully I took upclose photos and drew some rough diagrams so to resolder all the new parts in the right place.
I also checked those mica caps just to be 'sure to be sure'...They all checked fine.

Have now started on the vertical section....And that's where I'm at

Photos are of the repaired area and the dead bits including a slighty better picture showing a test pattern this time.

Cheers
Glen