[Amps] European Tube sources

[John Lyles]

For the record here:
Both Thompson and Amperex are still making glass tubes. Not all of the glass tubes, but the more profitable glass tubes. For instance, you can still buy 3-500Z from the Amperex Covimag factory in France. It was owned for a while by Richardson I believe, but it appears to be independent now, however Richardson does depend on this factory for product. We just bought some, they are used in one of our pulse amplifiers, and we had tried PRC tubes and gotten horrible quality for our first sample, so I avoid them now. See http://amfone.net/Amforum/index.php?topic=6841.0.

Thompson is now Thales, and still makes their tubes in the same factory in Thonon les Bains. I have visited it numerous times, last in March, and seen tubes with glass envelopes still being made - less of them though. They are having difficulties getting skilled glass makers (an art as well as skill) and getting enough glass tubing from suppliers too. Some of their HV pulsed modulator tubes, used in CAT scan machines for example, are being discontinued. Its unfortunate because for serious HV (like >100 kV) glass excels over most ceramic insulators. Thales also bought the Telefunken production as well as some of Seimens and the ABB high power line. All of these are now produced in the same factory, which helps them make these devices more economically. 

Last week I took home a pair of brand new matched 3-500Z in cartons, from the estate of a SK. They are marked matched, having paperwork stating such, and they have PRC stamps on them. Someday I will find out if they do indeed work that well, but right now I have good Eimacs in sockets in my Powerock 314R1 as well as an SB220. 

73
John
K5PRO

> Message: 3
> Date: Fri, 25 Jul 2008 09:27:49 -0400
> From: "Carl" <km1h at jeremy.mv.com>
> Subject: Re: [Amps] Tube sources

> Svetlana is still made in Russia or one of its ex republics AFIK. 
> Amperex/Thompson production Im not sure about. All other glass tubes are 
> Chinese no matter the brand name, no more USA. Taylor has a big logo with 
> San Marcos CA under it. Then on the side is the date code with PRC right 
> under it looking like part of the code.  A real con job from RF Parts.
> 
> ------------------------------
> 
> Message: 8
> Date: Fri, 25 Jul 2008 16:29:57 +0200
> From: "Peter Voelpel" <df3kv at t-online.de>
> Subject: Re: [Amps] Tube sources

> Amperex stopped glass tube production.
> A glass factory in Northern Germany were using 4-400B tubes from them as
> voltage regulators for there magnetron generators.
> When the tubes got unavailable they diverted to 8877, just needed to
> exchange the socket.
> For about 3 years they use now Chinese 8877 in about 50 generators without
> any trouble, unfortunately for that reason I could not obtain pulls so far.
> (but a couple of 4-400B with sockets and chimneys).
> They paid 400 Euro/tube in that quantity.
>