Sencore TC 131

[Findm-Keepm]

My childhood tester!!!!- Dad had one he got new. As a 5-year old, I busted the meter on his, and he got a new meter for it. I have another, with the manual and setup chart - glued to the base of the tester.

6GH8 - setup is 6-D-11-B - galvanized in my noggin from the 70s....

Tis only an emissions tester, and will lie. Won't do most hybrid set tubes, and few compactrons, but helpful with the shorts test and a quick go-no go.

Mine has corroded sockets and will be a treat to restore. Lemme wrassle that setup chart off and get it scanned. Gimme a week or two - my Canon MX860 crapped a print head, Error 051, and has locked all functions. I have access to another scanner on a Brother AIO, so lemme try that this weekend. I'll try to scan the stuff in jpg or gif - PDFs compile in huge file sizes. I'll also get the manual.

[dieseljeep]

Originally Posted by Findm-Keepm

My childhood tester!!!!- Dad had one he got new. As a 5-year old, I busted the meter on his, and he got a new meter for it. I have another, with the manual and setup chart - glued to the base of the tester.

6GH8 - setup is 6-D-11-B - galvanized in my noggin from the 70s....

Tis only an emissions tester, and will lie. Won't do most hybrid set tubes, and few compactrons, but helpful with the shorts test and a quick go-no go.

Mine has corroded sockets and will be a treat to restore. Lemme wrassle that setup chart off and get it scanned. Gimme a week or two - my Canon MX860 crapped a print head, Error 051, and has locked all functions. I have access to another scanner on a Brother AIO, so lemme try that this weekend. I'll try to scan the stuff in jpg or gif - PDFs compile in huge file sizes. I'll also get the manual.

Thanks for the response! I was just looking over it. I didn't realize it had the newer type sockets on it. The date of manufacture seems to be mid 1965.
You can take your time with any information, as I have several tube checkers. I just picked it up as something to look over.

[Findm-Keepm]

While you are waiting, get inside and replace the 20uF electro with a 22uF 100V cap, and swap out the high-megohm resistors in the grid circuit(s) - there should be a 5.6 Meg, a couple 10 Megs, and maybe one other high resistance IIRC. They greatly affect the accuracy. Dad's had drifted high - I never measured mine - just swapped them out with 2% 1/2W Corning metal film resistors (RCA used to package resistors like NTE, and that's what RCA used, Corning resistors...)


If you have some Deoxit cleaner, spray each socket and "exercise" them by plugging a tube in two or three times. Socket 11, 18 and a few others are/were heavily used - socket 11 being for triode-pentodes (6CG7, 6GH8, 6U8) and 18 for dual triodes (12AT7, 12AU7, 12AX7...). We used socket savers in both 11 and 18 on Dads. I killed his tester trying to test an 8LT8 - it wasn't listed, and I tried a combination that worked, but the tube tested low, so I jacked up the filament voltage to 10V, and cooked the power tranny. Dad had a B&K 747A, so the Sencore wasn't missed much (I think...).

[dieseljeep]

Originally Posted by Findm-Keepm

While you are waiting, get inside and replace the 20uF electro with a 22uF 100V cap, and swap out the high-megohm resistors in the grid circuit(s) - there should be a 5.6 Meg, a couple 10 Megs, and maybe one other high resistance IIRC. They greatly affect the accuracy. Dad's had drifted high - I never measured mine - just swapped them out with 2% 1/2W Corning metal film resistors (RCA used to package resistors like NTE, and that's what RCA used, Corning resistors...)


If you have some Deoxit cleaner, spray each socket and "exercise" them by plugging a tube in two or three times. Socket 11, 18 and a few others are/were heavily used - socket 11 being for triode-pentodes (6CG7, 6GH8, 6U8) and 18 for dual triodes (12AT7, 12AU7, 12AX7...). We used socket savers in both 11 and 18 on Dads. I killed his tester trying to test an 8LT8 - it wasn't listed, and I tried a combination that worked, but the tube tested low, so I jacked up the filament voltage to 10V, and cooked the power tranny. Dad had a B&K 747A, so the Sencore wasn't missed much (I think...).

I noticed The 'lytics and the 12AU7 tube. As of now, the meter wont electrically zero. I'll try the internal cal pot for now. I'm just going to put it back together until I get more information. I have too many projects started and not completed, one of my bad traits.