It was actually Jan-Erik SM2EKM (the other SM list member with a double first
name) that wrote that.
The 4X500 is very much a FM/TV transmitter tube (valve).
They were extensively used in the first generation European TV transmitters as
drivers.
73/
Karl-Arne
SM0AOM
----- Original Message -----
From: "Peter Chadwick" <g3rzp@g3rzp.wanadoo.co.uk>
To: "R L Measures" <r@somis.org>; <g3rzp@g3rzp.wanadoo.co.uk>
Cc: <amps@contesting.com>; "Hsu" <Jbenson@sohu.co>
Sent: Tuesday, July 25, 2006 10:59 AM
Subject: Re: [Amps] 3-500Z convertion
> Rich said:
> >no, I thought he said only one of the two tubes was bad.<
> Major confusion here........I thought he needed to replace both of them. From
> what Karl Arne said, it sounds a bit as if the 4X500 is 4-250/4-400 with a
> different base and an external anode. That makes them sound attractive,
> except for the fact that the shape of them is awkward - the anode cooler
> comes down very close to the glass envelope. I've a vague memory that they
> were originally meant for use in FM BC tx's, with a copper pipe tank circuit,
> down which the air was blown, but memory may be playing tricks. However, such
> a tank circuit would cool them effectively, although you'd need another fan
> on the bottom for the filament seals. They came out in about 1946/7 time.
> Still sounds like a major mechanical project on a TL922.
> 73
> Peter G3RZP
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.394 / Virus Database: 268.10.4/396 - Release Date: 2006-07-24
>
>
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.394 / Virus Database: 268.10.4/396 - Release Date: 2006-07-24
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|