Is this a longplate Holland Amperex??

[BrianH]

Was going through more of my 12AX7 tube collection and finally really inspected this mystery tube. Is that the Heerleen delta on the bottom of the tube?

I can't make out the getter because the flashing is so substantial, but it's either a slanted square or slanted D.

It's got the typical four "lines" in the top of the tube like all Amperex I've seen.

it'd be awesome if this is what this tube is. It tests at NOS and I don't think I paid more than a few bucks for it.

[novosibir]

If the plates are 17mm high, then it's a very rare Siemens & Halske from the 50's "Made in Germany"

Larry

[BrianH]

Thanks, Larry! 17mm it is. Any more info on this tube for me??

[novosibir]

Sorry, no more info. I've never tried it in a guitar amp.

Larry

[BrianH]

What indicates it's a Siemens & Halske over an Amperex? Curious to learn more!

This link would indicate it's an Amperex:
http://www.tube-classics.de/TC/Tubes/Va ... /ECC83.htm

[tubemonger]

If the plates are 17mm high, then it's a very rare Siemens & Halske from the 50's "Made in Germany"

Larry

Look at the date codes on the bottom. Delta or left triangle symbol is for Philips Heerlen production. mCA also makes it one of the earliest revisions.

[BrianH]

Awesome, thank you. I'll have to try it in V1 of my plexi clone. I'm almost afraid to use the thing since it tests NOS, heh.

[novosibir]

Look at the date codes on the bottom. Delta or left triangle symbol is for Philips Heerlen production. mCA also makes it one of the earliest revisions.

With the very old tubes it's sometimes really confusing. Of course the Delta sign indicates tubes made on the Philips plants in Heerlen, but the "mC" until now I've only seen on the very old Siemens & Halske tubes as mC1 or mC3.

In this case it's a mCA, but the number "1" is seen above it, what might have confused me

Sorry, but it seems that I've been wrong, so now I donate a cup of tea for everybody here

Larry