A little modulation with a pair of 810's would tickle your fancy!
8>)
Mike(y)
W3SLK
----- Original Message -----
From: Phil (VA3UX) <phil@vaxxine.com>
To: <amps@contesting.com>
Sent: Monday, September 18, 2000 9:22 PM
Subject: Re: [AMPS] Amp using 833A
>
> Now this is little more useful. Thanks for the input Tom.
>
> As I mentioned to Jeff, g-g would not be considered for this tube.
Neither
> would upper HF (these things are only rated for 30 Mhz max anyway). IF I
> do anything with these bottles, it will likely be moderate power on one to
> three of the lower HF bands, just for hacking around. Nostalgia rather
> power will be the motivation.
>
> Thanks
>
> Phil
>
> At 09:10 PM 9/18/2000 -0400, you wrote:
> >The problem is the tube will have low gain. That's because the gain
> >of a grounded grid PA is related to the ratio of output impedance to
> >input impedance of the tube.
> >
> >With it's low-mu construction, the 833 would take a heap of voltage
> >swing on the input meaning driving impedance would be high and
> >gain would be very low.
> >
> >It would be OK to grid drive the tube, but then stability becomes an
> >issue. The IMD also goes up because the heavy negative feedback
> >inherent in cathode driven systems (the output is in series and out-
> >of-phase with the input) would disappear.
> >
> >The tube could certainly be used, but it wouldn't be a good choice
> >(especially since they have long leads and are prone to self-
> >oscillation at upper HF).
> >
> >
> >73, Tom W8JI
> >w8ji@contesting.com
> >
> >--
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> >Submissions: amps@contesting.com
> >Administrative requests: amps-REQUEST@contesting.com
> >Problems: owner-amps@contesting.com
> >
> >
> >
>
>
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