Amps
[Top] [All Lists]

Re: [Amps] 4-400A ratings

To: "Vic K2VCO" <vic@rakefet.com>, "Amps reflector" <amps@contesting.com>
Subject: Re: [Amps] 4-400A ratings
From: "Carl" <km1h@jeremy.mv.com>
Date: Mon, 9 May 2011 17:07:35 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>
With 3KV, plus enough drive and screen voltage you will have a hard time 
keeping them under 400 ma at full load. All they need is air to stay happy.

Carl
KM1H


----- Original Message ----- 
From: "Vic K2VCO" <vic@rakefet.com>
To: "Amps reflector" <amps@contesting.com>
Sent: Monday, May 09, 2011 2:01 AM
Subject: [Amps] 4-400A ratings


> I've come into a pair of 4-400A's. I'm thinking about building an 
> amplifier with one tube
> and using the other for a spare. Looking at the data sheet for class-C CW, 
> the maximum
> rated plate current is 350 ma. This means that at 3 kV on the plate I can 
> expect to get
> only about 750-800 watts output. This does not come close to utilizing the 
> 400-watt plate
> dissipation of the tube.
>
> At 4 kV, I could get 1400 watts input and about 1050-1100 out. That's a 
> lot better. But it
> means a lot of extra expense -- the power supply, tuning capacitor, etc. 
> need to be bigger.
>
> Is this correct? Why is the plate current limited to 350 maA? Is it a 
> limitation on
> filament emission?
>
> Of course I can use both tubes and get full legal power. But then I need 
> another socket,
> chimney, etc. Or maybe I can use the "SB220 cooling method" and cheaper 
> sockets.
> -- 
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1325 / Virus Database: 1500/3626 - Release Date: 05/09/11
> 

_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

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