For 6AS7G tube rollers here .....
May 30, 2022 at 9:52 AM Post #8,881 of 8,991

whirlwind

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And I've got some Type 27's that were manufactured around 1930, and they still sound fine. :)

This is what is really amazing to me, that some of these tubes that are 80-90 years old and work flawlessly.
This is really cool to me. I usually always prefer the older if given the choice.
 
May 30, 2022 at 11:03 AM Post #8,882 of 8,991

toddc2

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According to my TV-7D/U chart the minimum reading is "40" which is a Gm of 5000. The test data for a 421A is a little different from a 6AS7/6080. Of course how tube tester readings correspond to audio performance is a whole different discussion
Most of the recent listing I've seen for the 421A have been tested on a TV-7 with Min Good as 40. The test results are all around 65-70 or so although I've seen a few SOLD ads with results of 80. Does anyone know the NOS bogey for the 421A on a TV-7?
 
May 30, 2022 at 9:18 PM Post #8,883 of 8,991

CAJames

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Most of the recent listing I've seen for the 421A have been tested on a TV-7 with Min Good as 40. The test results are all around 65-70 or so although I've seen a few SOLD ads with results of 80. Does anyone know the NOS bogey for the 421A on a TV-7?

The long answer is the datasheet value for Gm is 18000 - 20000 which would be (way) off scale on the TV-7, so they are clearly talking about a different operating point (see relevance of tube tester results to audio performance). The short answer is I don't know :question::question::question: That sort of speaks to the intended purpose of tube testers: determining if a tube is bad, not if it is good.
 
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May 30, 2022 at 11:07 PM Post #8,884 of 8,991

mordy

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The long answer is the datasheet value for Gm is 18000 - 20000 which would be (way) off scale on the TV-7, so they are clearly talking about a different operating point (see relevance of tube tester results to audio performance). The short answer is I don't know :question::question::question: That sort of speaks to the intended purpose of tube testers: determining if a tube is bad, not if it is good.
The intended purpose of tube testers: determining if a tube is bad, not if it is good.
That sounds like the truth!
 
May 31, 2022 at 8:39 PM Post #8,885 of 8,991

bcowen

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Most of the recent listing I've seen for the 421A have been tested on a TV-7 with Min Good as 40. The test results are all around 65-70 or so although I've seen a few SOLD ads with results of 80. Does anyone know the NOS bogey for the 421A on a TV-7?
Several different companies made the TV-7, but most were made by Hickok. The minimum good value with most all Hickoks is 60% - 65% of bogey, so that would put bogey right around 70, +/- a few points on the 421A. There's likely far more variance in the tester readings than the absolute bogey value though, as there are too many TV-7's out there that have been neither rebuilt or calibrated in decades. Unless a seller purposefully points out that their tester** has been rebuilt and calibrated within the last several years, the data provided is suspect at best.

**referring just to vintage testers here, not current or recently manufactured ones.
 
May 31, 2022 at 10:07 PM Post #8,886 of 8,991

Velozity

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Just a friendly tip, if anyone needs some tested and auditioned 6AS7G or 2399/5998 tubes, I am going to be selling my entire stash. I have about 20-24 tubes total I think, mostly Chathams. I will probably bundle 2 or 4 to sell with the GOTL but the rest are up for grabs. Classifieds listing coming later this week. Here's a teaser pic with some of them:

IMG_4180.jpeg
 
Jun 1, 2022 at 3:11 AM Post #8,887 of 8,991

bpiotrow13

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Just a friendly tip, if anyone needs some tested and auditioned 6AS7G or 2399/5998 tubes, I am going to be selling my entire stash. I have about 20-24 tubes total I think, mostly Chathams. I will probably bundle 2 or 4 to sell with the GOTL but the rest are up for grabs. Classifieds listing coming later this week. Here's a teaser pic with some of them:

IMG_4180.jpeg
Man, I do not ask what has made You selling these as this is probably a serious thing, but these tubes are awesone.

I probably have similar amount of tubes but now see that it is a bif mistake to keep them in the box:wink:
 
Jun 1, 2022 at 9:36 AM Post #8,888 of 8,991

Thaddy

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Just a friendly tip, if anyone needs some tested and auditioned 6AS7G or 2399/5998 tubes, I am going to be selling my entire stash. I have about 20-24 tubes total I think, mostly Chathams. I will probably bundle 2 or 4 to sell with the GOTL but the rest are up for grabs. Classifieds listing coming later this week. Here's a teaser pic with some of them:

IMG_4180.jpeg
I've wanting another pair of Chatham/Tung-Sol 6AS7G's, I'd love to snag a pair or two.
 
Jun 1, 2022 at 11:05 AM Post #8,889 of 8,991

Odin412

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Just a friendly tip, if anyone needs some tested and auditioned 6AS7G or 2399/5998 tubes, I am going to be selling my entire stash. I have about 20-24 tubes total I think, mostly Chathams. I will probably bundle 2 or 4 to sell with the GOTL but the rest are up for grabs. Classifieds listing coming later this week. Here's a teaser pic with some of them:

IMG_4180.jpeg
Wow - please let us know when your listing is up!
 
Jun 5, 2022 at 9:28 AM Post #8,892 of 8,991

JTbbb

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Jun 15, 2022 at 1:58 PM Post #8,895 of 8,991

NE 6AS7G USSR

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I found this forum through Google search, and was wondering if any of you had interest in purchasing any National Electronics 6AS7G tubes (have several) made in USSR? If this isnt appropriate, please let me know and I'll either put in the the classifieds section or Ebay.

How to I insert picture without url?
 

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