[tintinsnowydog]

Just received 4 of these General Electric Canada 6SN7GT, any insight onto their history, what the gray collar may be for and date? Has date code H3 as far as I can see.

 

[JKDJedi]

Just received 4 of these General Electric Canada 6SN7GT, any insight onto their history, what the gray collar may be for and date? Has date code H3 as far as I can see.

Those might be Sylvania, and the collar could be a remedy for a loose base.

 

[tintinsnowydog]

Those might be Sylvania, and the collar could be a remedy for a loose base.

Construction does look almost identical to a couple Sylvania VT231 I can see, just the bottom getter is different (rectangular open getter). Did Sylvania operate factories in Canada? Wonder if anything else would narrow down the date ranges.

 

[JKDJedi]

Construction does look almost identical to a couple Sylvania VT231 I can see, just the bottom getter is different (rectangular open getter). Did Sylvania operate factories in Canada? Wonder if anything else would narrow down the date ranges.

Then probably CBS-Hytron . Not sure if Sylvania ever did have factory in Canada, but a lot of tubes did get outsourced to Canada. Marconi is one company that comes to mind that had almost all their tubes outsourced.

 

[lupoal]

Hi,
I have here two tubes that looks like Sylvania but, unfortunately, do not have any name anywhere... here are some pictures, is there anybody that could help me in recognize them? Do thanks in advance

 

[Ranger Ron]

Then probably CBS-Hytron . Not sure if Sylvania ever did have factory in Canada, but a lot of tubes did get outsourced to Canada. Marconi is one company that comes to mind that had almost all their tubes outsourced.

Rogers branded tubes out of Canada all look very similar to sylvania.

 

[Tom-s]

Here's a riddle for everyone!
Haven't found a picture online of a second specimen, that's why it's here for you!

I'm a warm sounding European SN7 and I lack controlled heater warm-up.
What am I?

 

[bcowen]

Here's a riddle for everyone!
Haven't found a picture online of a second specimen, that's why it's here for you!

I'm a warm sounding European SN7 and I lack controlled heater warm-up.
What am I?

Hmmm...perhaps a Brimar 6SN7GTY?

 

[Ranger Ron]

Hmmm...perhaps a Brimar 6SN7GTY?

Fivre?

 

[JKDJedi]

Here's a riddle for everyone!
Haven't found a picture online of a second specimen, that's why it's here for you!

I'm a warm sounding European SN7 and I lack controlled heater warm-up.
What am I?

You'll have to send that to me for further evaluation, Brimar?

 

[Tom-s]

Thanks for playing along guys, much appreciated! No one's close.

Another set of hints. This is the current setup (don't do OPT rolling, hugely impractical as can be seen).
The output tubes will teach you the heater voltage. The code seen, the Island of origin. The before told hints the actual brand.
The actual factory was owned by different "companies" over the years. In the early '50s this company (and it's parent company) took over and produced this tube (apparently).

 

[JKDJedi]

Thanks for playing along guys, much appreciated! No one's close.

Another set of hints. This is the current setup (don't do OPT rolling, hugely impractical as can be seen).
The output tubes will teach you the heater voltage. The code seen, the Island of origin. The before told hints the actual brand.
The actual factory was owned by different "companies" over the years. In the early '50s this company (and it's parent company) took over and produced this tube (apparently).

And this is a 6sn7 tube correct? Nice amp, custom?

 

[attmci]

Here's a riddle for everyone!
Haven't found a picture online of a second specimen, that's why it's here for you!

I'm a warm sounding European SN7 and I lack controlled heater warm-up.
What am I?

We had discussed b4. There is no Mullard 6SN7GT. https://www.whatsbestforum.com/threads/mullard-6sn7gt-help-please-info-needed.15277/

They are all made by _______ . hahaha.

 

[JKDJedi]

We had discussed b4. There is no Mullard 6SN7GT. https://www.whatsbestforum.com/threads/mullard-6sn7gt-help-please-info-needed.15277/

They are all made by _______ . hahaha.

Most likely Brimar.

 

[Ripper2860]

Not sure what the mystery tube is, but while it does look similar to a Brimar, I'm going to go with it not being Brimar. Top mica is just not what I'm used to seeing on a Brimar 6SN7GT/Y or CV1988.