[JTbbb]

So your metal 6sn7w doesn't have the support rod? I thought they all did. And that 6sn7aw has one? I thought only the metal based ones had them. I'm even worse informed than I thought lol.

OK, not the best of pics. But do I see a metal support rod in these non metal based? I think so.

 

[triod750]

OK, not the best of pics. But do I see a metal support rod in these non metal based? I think so.

Yes, they have a metal support rod, mine too.

 

[Isaacc7]

OK, not the best of pics. But do I see a metal support rod in these non metal based? I think so.

They do indeed. Interestingly, at least to me, they seem to have the same support rod as my 7N7 but not the copper one like the metal base 6sn7w and 14n7. Dunno where I got the idea that only the metal base 6sn7w had a support rod.

 

[Renexx]

They do indeed. Interestingly, at least to me, they seem to have the same support rod as my 7N7 but not the copper one like the metal base 6sn7w and 14n7. Dunno where I got the idea that only the metal base 6sn7w had a support rod.

Those are the successor of the Sylvania 6sn7 metal base. First came black base tall bottle and then later in time black base short bottle. Same internal construction.

 

[whirlwind]

OK, not the best of pics. But do I see a metal support rod in these non metal based? I think so.

Nice tubes

 

[JTbbb]

Those are the successor of the Sylvania 6sn7 metal base. First came black base tall bottle and then later in time black base short bottle. Same internal construction.

I wonder when Sylvania started production of the 6sn7W? Mine are the short bottle dated April ‘45

 

[Renexx]

I wonder when Sylvania started production of the 6sn7W? Mine are the short bottle dated April ‘45

My pairs of Metal and black base all are 1945. I have another pair of commercial rebranded metal base dated 1947.
Actually i thought they are very early 40s but they are not. Sylvania vt-99 6f8g should have an earlier vintage as predecessor.

 

[JTbbb]

Are these January and February ‘44

Or are they April ‘44

 

[Renexx]

Are these January and February ‘44


Or are they April ‘44

Both January 1944. A4 means 1st and 2nd week, b4 3rd and 4th week.

Interestingly the etched date code on the glass seems to be earlier than 4D code on the base. Not all have that date code on the base.

 

[Isaacc7]

I wish there were date codes on the loctal tubes. Would be handy.

 

[Isaacc7]

Once again I've been shown to be a moron. If I had bothered to look at the tubes I actually own I might have noticed...

That is one of my brown base Sylvania 6sn7w and yup, there's the rod! Was this made in 42?

 

[triod750]

Is this a W or a WGT?
You are just a normal person and less of a nerd.

 

[Isaacc7]

Is this a W or a WGT?
You are just a normal person and less of a nerd.

It is a WGT. Doing a little investigation this was probably made in the 60s or 70s I think. How to decipher the date code though?

 

[nykobing]

It is a WGT. Doing a little investigation this was probably made in the 60s or 70s I think. How to decipher the date code though?

42nd week of the year 1952.

 

[TLO]

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