[Amps] G2DAF four 4CX250Bs G2DAF amplifier

[Hsu]

Peter,
  I have seen the debate about G2DAF many  years ago in the list, But I want to know, the G2DAF amplifier's IMD spec.
if it did not under -30db or -25db, it should be  valuable.
 73! Hsu
----- Original Message ----- 
From: "Peter Chadwick" <g3rzp at g3rzp.wanadoo.co.uk>
To: "Hsu" <Jbenson at sohu.co>; <amps at contesting.com>
Sent: Thursday, August 03, 2006 3:50 PM
Subject: Re: [Amps] G2DAF four 4CX250Bs G2DAF amplifier


> Hsu said:
>>the next Plan is four FU-251F(Same as 4CX250B) G2DAF amplifier,I would like to hear any good suggestion about it.<
> DON'T DON'T DON'T!!!!!
> The G2DAF is not very good for linearity, despite the claims. Neither is the 4CX250B, without negative feedback, and a well regulated screen grid supply, capable of absorbing negative screen current.  In a G2DAF circuit, you could get all sorts of problems from the negative screen current, especially as there's no low dc resistance path back to cathode.
> I think Rich will agree - I don't remember him being a great advocate of the G2DAF except perhaps, for filling dumpsters with them!
> 73
> Peter G3RZP
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