[Amps] output of SB220 typical TSPA

[k7rdx]

Agreed Tom...My question was why would someone run an amp with that value of
line voltage if he knew the effect it would have on the fils.I do know for a
fact that a lot of the Chinese 3-500z tubes have higher gain than the older
Eimacs...I personally wouldn`t argue over a few hundred watts if I were
using 3-500`s because the guys hearing you won`t know the diffrence
anyway...Isn`t that why we run tubes with "Handles"? 73,Jim..
----- Original Message ----- 
From: "Tom W8JI" <w8ji at w8ji.com>
To: "k7rdx" <k7rdx at charter.net>; "Joe Isabella" <n3ji at yahoo.com>; "Amps"
<amps at contesting.com>
Sent: Monday, July 17, 2006 4:19 PM
Subject: Re: [Amps] output of SB220 typical TSPA


>
> > Joe,what was the filament voltage with that kind of line
> > input? Excessive
> > filament voltage allows more than normal emission with
> > thoriated tungsten
> > fils...At least for a while! 73, Jim K7RDX..
>
> Jim,
>
> A single tube will easily make 1200 watts or more  with
> enough drive at 3000 volts, and you don't have to run the
> filament extra hot to do it.
> There isn't any doubt at all people are seeing 2kW or more
> from a pair when they bang them with 150 watts or more at
> 3kV or more.
>
> The problem is with claims that a pair in g-g run 1500 watts
> or more out with 100 watts of drive and about 3kV on the
> anode. It really won't happen, even if you put 10 volts on
> the filament. The problem is power gain, and the gain is
> largely set by the ratio of cathode driving impedance to
> anode load impedance in a g-g amp. The only way to get more
> gain is by running more HV so the anode impedance is higher.
>
> 73 Tom
>