Gary and all: I have built a couple amps and repaired a few and modified the
inputs on some and had good luck with the pi-net input ckts. my homebrew is
4-811a's, and I've reworked some sb200's with no trouble, HOWEVER, I'm now
working on a gla1000 and it's a nightmare. I haven't been able to get a. pi
type ckt. to work but I discovered that a tee network will do it fairly
well. Accidents do happen now and then. With EL509's the input capacity is
ungodly High.along with the stray capacity it's in the the 110 pf area. I'm
not the expert here I know , but I'll wait and see who else gets into this
discussion!!!have a good day!!
carl / kz5ca
----- Original Message -----
From: "wlfuqu00@uky.edu" <Wlfuqu00@uky.edu>
To: "Gary Smith" <mandolinist@interlync.com>; <amps@contesting.com>
Sent: Friday, April 19, 2002 10:19 AM
Subject: Re: [Amps] Thinking about building an amp.
>
>
> At 09:29 PM 4/18/02 -0500, Gary Smith wrote:
> >I was thinking it might be nice to use one of the
> >automatic tuners like the AT-11MP instead of making a fixed tuned
> >input. Seems like the AT-11MP would find a nice match regardless
> >of where I tuned.
>
> If you had a capacitor between cathode and ground who's capacitive
> reactance is say 1/5 of the cathode resistance and if the AT-11MP
> would match it then you should have your fly-wheel effect and a Q of at
> least 5. However, this may require switching in a different capacitor for
> each band.
>
> 73
> Bill wa4lav
>
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