Amps
[Top] [All Lists]

[AMPS] WTB B+ xformer etc

To: <amps@contesting.com>
Subject: [AMPS] WTB B+ xformer etc
From: G3SEK@ifwtech.demon.co.uk (Ian White, G3SEK)
Date: Mon, 11 Oct 1999 09:06:15 +0100
Shane KI4M/KV4I wrote:
>
>       I am need of a B+ xformer for an amp that I am considering to purchase. 
>I
>need a supply that will deliver after the filter caps 3000-4500V @1.2A or
>so. Would like around 4000V no key. This is for a GS35b triode for 432 MHz.
>Does anyone have such a beast laying around that they would like to sell? An
>MRI xformer would work great. 220V input only also as if you need to know
>hihi. Also going to need some caps for this project. Anyone got a set laying
>around collecting dust. Need 100uF or so @ the above listed voltage. 

You'll see a comfortable 1500W at 3500V on-load, so 4000V off-load and
about 3800V key-up (150mA) sounds good. 

But 100uF is way too much - about 30uF will be plenty. The extra
capacitance will only store up more energy, which will be dumped into
the tube when there's a flashover... and at 4000V there *will* be
flashovers. 

I hope you're aiming this amp at the moon - see you in the ARRL EME
contest!

73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
                           http://www.ifwtech.demon.co.uk/g3sek

--
FAQ on WWW:               http://www.contesting.com/ampsfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>