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  #1  
Old 01-18-2017, 10:30 AM
dieseljeep dieseljeep is offline
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Sencore TC 131

Bought it at the WARCI auction, just for S&G's. The setup chart is missing!
I'd like to see if it works, without too much effort.
It seems to be a self service counter type. It seems to test tubes made until the late 50's, no UX types.
BAMA doesn't list it.
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  #2  
Old 01-18-2017, 04:04 PM
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Findm-Keepm Findm-Keepm is offline
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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.
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  #3  
Old 01-18-2017, 07:45 PM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by Findm-Keepm View Post
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.
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  #4  
Old 01-19-2017, 07:39 AM
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Findm-Keepm Findm-Keepm is offline
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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...).
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  #5  
Old 01-19-2017, 11:30 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by Findm-Keepm View Post
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.
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  #6  
Old 01-20-2017, 01:50 AM
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Tubejunke Tubejunke is offline
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As a kid I could walk with a bag of tubes to the town "electronics" shop. They had a stereo sound test room, a tube room for retail sales and to supply the guys in the shop around back where the owner and another tech repaired TV, stereo equipment, HAM, and music amplification. The C.B. radio thing was still going on, so they did a lot of installs and tweaks with that stuff. The sales floor was better than what Radio Shack was when Radio Shack was still what the name implies. If they didn't stock a part, then they could get it. They also had a table model of the then common commercial tube tester complete with a lighted sign and what looked like a hundred sockets, two knobs, a neon bulb and of course a meter. Seems it could test anything from the early "big pin" stuff through the latest compactron style tubes. Good times!

Time moved on and I joined the Army for a number of years and came home. I decided to visit the radio shop. Everything was gone! The sales floor was populated with automotive windshield popper, neighborhood shaker bass insane related goods. The tube tester was gone. The stereo listening room's couch was gone and the shelves were packed with boxed goods. Wow! Had the world changed that much in a few years?

I saw the familiar face of the owner (still there today) and asked what had happened. Long story short and as we all know the market had simply changed. The repair end was gone only leaving techs to doing car stereo installs or upgrades. HOWEVER, he said that he still had the tube tester back in the shop. While I was gone a roof leak had saturated it according to him and damaged it. He ended up giving it to me back before I had nicer and more practical equipment like my Hickok stuff.

I never really saw where water hurt the thing. The cardboard charts had some wrinkles, but few. The damage was that the meter's pointer was broken off. Not sure how rain made that happen!?!?!? Either way it goes the thing ended up having some electrical issue which at the time I had no clue what to do to repair AND about that time I acquired a Sylvania 140 which is hands down one of the best testers I have (still have today). So needless to say the huge old memory went the way of the Edsel and to the shed where the need for space often means give away, part out, or trash. I think I saved the plastic sign that lit at the top of the unit and a transformer.

I have regretted more than one radical move in the name of needed space, but I never really felt bad about trashing the old memory of an emissions tester. As the Internet got bigger and Ebay became a way of life, it's easy to see how common and fairly cheap a basic emissions tester generally is. They have their place. Especially if you have nothing else.

The electronics store is still there today and recently sold me a high voltage probe, and o-scope, and signal generator very reasonably. AND they still have the room full of tubes that never sold! Yup! He's no dummy though. He still has a current price list that he uses, but I believe it's based on one of the foreign manufacturers prices, yet what's on the shelf is old gold.
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  #7  
Old 01-20-2017, 10:48 AM
dieseljeep dieseljeep is offline
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Sencore TC131

I tried testing a 6GH8 using the only data on hand. Is there only one setting? Naturally, it checked good! The tester must tie all the sections together and test them as a single tube.
I like the neon lamps that indicate the scale used and the switch setting.
I'll replace the 'lytic and check the resistors, when I get the rest of the information.
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