Wonder which factory manufactured this tube for Zaerix. It has a transparent disc with a strange pattern on the upper mica and is marked E74 on the glass. Four seams on top. The inner structure is askew, sloppily mounted or the result of bad handling. Doesn't sound bad, piqued my curiosity.
Attachments
Looks like any number of Philips clones. If the etched 'E' is a factory code, then it could be Hyperlec Brive.
From what I found on the net by comparing the plates, the getter, the shape of the glass welding and the assembly on photos, it could be Mullard Brimar origin.
The etch code is incomplete and/or sloppy. It should be two lines of three digits. VFx for ECC81, VGx for E81CC. Below that the factory and date code.
The construction and mica looks like my Mullard, but in Blackburn they got the codes right.
My guess would be that it's from the last European factory that used Philips equipment: Ei (Yugoslavia).
The construction and mica looks like my Mullard, but in Blackburn they got the codes right.
My guess would be that it's from the last European factory that used Philips equipment: Ei (Yugoslavia).
No way was anything from Z&I (Zagiel and Igel) Aero ever Brimar or Mullard. The shop (on London's Tottenham Court Road) sold exclusively Soviet stuff. Zaerix was their own brand. Quality control was what you would expect from 70s Soviet. I suppose you could call that "Special Quality"!
If that's a "not equals" symbol before what looks to be 74 then it's a Siemens tube. Bit hard to see.
They don't look like soviet or east block tubes to me. Usually the eastern tubes have red-looking pins (insert smirk here) where they pass through the glass..
They don't look like soviet or east block tubes to me. Usually the eastern tubes have red-looking pins (insert smirk here) where they pass through the glass..
These valves appear to be late manufacture three grid alignment hole garden variety 12AT7/ECC81 by a Philips licensee , rather than a special quality type such as those by Siemens / Valvo etc . $225 is a staggeringly stupid amount to pay for ANY pair of ECC81 IMHO
Here's a Philips marked ECC81, manufactured by Mullard in Blackburn (Heerlen manufactured ECC81 does not have that transparent disc on the top getter as far as I've seen).
The Mullard is almost identical to the Zaerix except that the latter has four seams on top which apparently no Mullard has. I think EI is a good guess as the factory behind the Zaerix. Is there any source confirming that EI took over Philips machines and tools in the 1970s?
Zaerix time:
The Mullard is almost identical to the Zaerix except that the latter has four seams on top which apparently no Mullard has. I think EI is a good guess as the factory behind the Zaerix. Is there any source confirming that EI took over Philips machines and tools in the 1970s?
Zaerix time:
According to my 1970 databook VALVO Handbuch Spezialröhren, Valvo (and probably any other other tube maker under Philips' care) never made any E81CC's. Instead, they called their SQ version of ECC81's 6201. Additionally, I'm missing the pinch envelope that was typical for genuine Philips/Valvo etc. SQ tubes. Hence, I agree with you who said that these tubes might have been made in Eastern Europe with the help of old Philips machines and can't even exclude that these are plain customer quality ECC81's, hence fakes.
Best regards!
Best regards!
Late reply, but with JacobLTA's photo and Kay Pirinha's comments I think we can safely identify this as an EI manufactured tube, a good but ordinary ECC81. Z&A Aero Services wouldn't hesitate to "improve" the tube by naming it E81CC, apparently they illegally sold American tubes to Cuba in the 60s.