From: patriot121@msn.com
To: jan@on6zg.be
Subject: RE: [Amps] GS35b Bias
Date: Tue, 9 Mar 2010 15:01:59 -0800
Yea, G3SEK uses a TL431 and a PNP pass transistor .... Im just trying to get by
on whats already there ... Does any one else have comments about Noise from the
LM317t compared to the TL431 ???
Mike
KC7NOA
> snip> Subject: RE: [Amps] GS35b Bias
> Date: Tue, 9 Mar 2010 21:54:25 +0100
>
> I'm using a tip147 or BD equivalent. You can also check G3SEK triode board
>
> 73 Jan ON6ZG
>
> -----Oorspronkelijk bericht-----
> Van: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] Namens
> MIKE DURKIN
> Verzonden: dinsdag 9 maart 2010 0:57
> Aan: ka4inm@tampabay.rr.com; amps fourm
> Onderwerp: Re: [Amps] GS35b Bias
>
>
> thats right ... my amp does not have a PNP, only NPN trans good to 1200v@10A
> .... i want to replace the minum of parts ...
>
> You dont see an improvement ?? I was leaning towards a variable Bias with a
> LM317t and a NPN pass transistor .. simply because its what i have ... and
> im trying not to buy anything.
>
> Mike
> KC7NOA
> > >
> > Hi MIKE DURKIN:
> >
> > > ok, I made a quick draw of what im wanting to do .. basically replace
> > > the Zener in the all black drawing .. I forgot to add a Blocking diode
> > > in series ok the 1k resistor that's tied to the NPN transistor ..
> >
> > I see no PNP, but if the circuit on the left is the original it is an
> "amplified Zener."
> > The LM317 will generate much more noise and not be any improvement that I
> can see.
> > --
> > Ron KA4INM - I'm proud to be Chuck's pop!
Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. Sign up now.
_________________________________________________________________
Hotmail: Powerful Free email with security by Microsoft.
http://clk.atdmt.com/GBL/go/201469230/direct/01/
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|