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I have a couple 6V6GT tubes. They're older GE and Raytheon.

 

Numbers found on the base are:

 

Raytheon 280 6-17

GE 4-39 188-20

 

Can anybody tell me when these were manufactured? I'll take some pics if anybody's interested.

 

Those arn't peas or corn in a can... you can plug those tubes in

anytime you want and if new they will work.

They won't spoil.

 

Those are probably run numbers for quality control more than

likely.

 

Those tubes should be in specs per the GE or Raytheon tube manual specs.

 

CHEEKS

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Well, for anybody who's interested, at the very least I'm documenting this for myself. I finnally tried the old tubes. The bad new is somehow my NOS JAN 6v6GT broke. The middle black plastic part broke. I noticed it while putting it back in after the GE and Raytheon. The good news is the GE sounds sweet! Very cool distortion. Just a really good overall sound. The Raytheon sounds a bit harsh. A good backup tube. Not sure when the JAN gave out although since day one it did have some hickups now and then. I'm guessing it was cracked when I bought it. I really dig the GE. Happy day!

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Yeah, they don't look like vegetables to me either. I'm guessing they're from the 50s or 60s. I can't find the specs on the web. Does anybody know why the GE has 6 pins instead of the usual 7? I mean, all my other 6V6s have 7 pins.

-

 

IF i recall, some tubes had an extra ground pin for the cathode i think...

it's been years since i restored old antique radios...

 

CHEEKS

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A tube amp tech could probably come close to year of manufacture, based upon the general construction of the tubes, but it really doesn't matter. They may be great or they may be useless. Oftentimes, NOS tubes become gassy over the years of lying around, sometimes they're excessively microphonic, and sometimes they're not really NOS at all, but instead have significant miles on them. The only way to know for certain is to have them tested for gain and conductance.

 

As for hanging onto bad NOS tubes, for use as a "backup," you'd probably be better off getting a new production 6v6. There are some very good new production 6v6s available today that are quite cheap.

 

Btw, the centering pin can break and not destroy the tube. As long as the glass remains intact and you're careful to line it up properly when installing it, it'll work just fine. I ran a pair of 6ca7's like that throughout their lifespan, with no problems whatsoever.

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A tube amp tech could probably come close to year of manufacture, based upon the general construction of the tubes, but it really doesn't matter. They may be great or they may be useless. Oftentimes, NOS tubes become gassy over the years of lying around, sometimes they're excessively microphonic, and sometimes they're not really NOS at all, but instead have significant miles on them. The only way to know for certain is to have them tested for gain and conductance.

 

As for hanging onto bad NOS tubes, for use as a "backup," you'd probably be better off getting a new production 6v6. There are some very good new production 6v6s available today that are quite cheap.

 

Btw, the centering pin can break and not destroy the tube. As long as the glass remains intact and you're careful to line it up properly when installing it, it'll work just fine. I ran a pair of 6ca7's like that throughout their lifespan, with no problems whatsoever.

Thanks for chiming in m-theory. I was hoping you would. Interesting note on the broken centering pin. I'll check that out.

 

As for the GE, it seems like it's from the 40s from what I'm gathering on the web. It sounds real creamy. I'm getting 6 more tubes from my friend. Two 6V6GTs, two 12AX7s and two 5Y3GTs. Those are what go in my amp. One of each. I asked him to look for GE, RCA or anything stamped JAN. He's an old radio guy. Has hundreds of tubes stashed away.

 

I'd like to get the tubes tested like you say. I'm not sure where to take them. All I know is the GE sounds the best so far in my amp. I've had a modern JJ/Tesla, a Tungsol re-issue and a NOS JAN Phillips in the 6v6 slot so far. Oh, and a 6L6 JJ too. The circuit is based on the Fender Princeton 5F2a, so the old tubes I have coming should be a nice fit.

 

I realize there are some decent new tubes for cheap ala the JJ/Tesla brand, it's just money is tight these days and I'm getting these tubes for free. Free is good, right? [biggrin]

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Free is my alltime favorite price, without a doubt!

 

Years ago, I got cozy with an old TV guy, when I built a Tesla coil for a science fair project, and required some assistance along the way. Great guy, and was totally willing to help out, which was way cool. Unfortunately, by the time I figured out that NOS tubes were valuable, he was long gone. I also used to buy tubes from another old TV repairman years ago, and I called him up about 10 years ago, only to learn that all of his NOS 6l6s, 6v6s, and 12ax7's, among others, had long since been snatched up by others. He used to sell tubes off his shelf for whatever price he'd stamped on them when he stocked them, so if it was a tube that he put in inventory in the early 60's, it might have a $1.75 price tag on it.

 

A tube amp tech would test those tubes for you for a very small fee. Rock on.

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A tube amp tech could probably come close to year of manufacture, based upon the general construction of the tubes, but it really doesn't matter. They may be great or they may be useless. Oftentimes, NOS tubes become gassy over the years of lying around, sometimes they're excessively microphonic, and sometimes they're not really NOS at all, but instead have significant miles on them. The only way to know for certain is to have them tested for gain and conductance.

 

As for hanging onto bad NOS tubes, for use as a "backup," you'd probably be better off getting a new production 6v6. There are some very good new production 6v6s available today that are quite cheap.

 

Btw, the centering pin can break and not destroy the tube. As long as the glass remains intact and you're careful to line it up properly when installing it, it'll work just fine. I ran a pair of 6ca7's like that throughout their lifespan, with no problems whatsoever.

 

I have used may RARE tubes that had broken off center bakelite pins... just align that tube

cafefully and properly upon insertion and it will work fine.

 

Gassy tubes are generally caused by a defective seal around on of the pins that leads

through the glass. Tubes are a throw away anyway... like a tungsten light bulb.

The have a more or less measured life span.

 

CHEEKS

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Well. The tubes came today! Here's a shot of them. 6V6GTs on the left, 12ax7s in the middle and 5Y3GTs on the right. Can't wait to try them out.

4930829176_47b2f7b915.jpg

 

The 6V6G and i believe the 5Y3G had huge large glass

envelopes.... as opposed to these tiny glass envelopes...

 

I think the large glass covers lasted longer than these tiny

glass covered tubes... especially the 5Y3 rectifier which is a

HOT RUNNING tube anyway... the more current that the rectifier

has to rectify, the HOTTER that baby gets... hence they are

realatively short lived tubes.

 

6v6g.jpg 6V6G

 

tube5y3.jpg 5Y3G

 

CHEEKS

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I think people trip out on the smell of hot dust on top of a

HOT tube... and the neat looks of that glass robot

and the little glow it gives...

 

I think it is nuts.

They have a measured life span... like you and me.

....and it ain't that long either....

 

tubes... pain in the behind...

 

CHEEKS

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