OK Conrad - thanks for the feedback. I read what
you just said, but I don't understand why the screen
would have a problem. I vaguely remember seeing something
like this on a web site. Was it the measures page/s?
Of course, I guess if the plate voltage got very low, I
could see a problem developing.
Doug N4IJ
conrad.farlow@virgin.net wrote:
>
> ----- Original Message -----
> From: "Douglas Snowden" <Douglas.R.Snowden@noaa.gov>
> To: <amps@contesting.com>
> Sent: Tuesday, April 10, 2001 1:31 PM
> Subject: [AMPS] MLA2500 and screen voltage for 4CX800.
>
> >
> > I have decided to put a 4CX800 in the MLA2500
> > sitting on the bench. I don't have a copy othe old QST (96?)
> > article on doing this, but I remember seeing that they used some sort of
> > regulator
> > board to make screen voltage. Wouldn't a string of
> > zeners off of the plate voltage supply be just as good, and
> > take up less space? Anything wrong with this idea?
> >
> > Doug N4IJ
> >
> >
> >
> > --
> > Doug Snowden
> > Systems Branch
> > National Climatic Data Center
> > Asheville, North Carolina
> >
> > --
> > FAQ on WWW: http://www.contesting.com/FAQ/amps
> > Submissions: amps@contesting.com
> > Administrative requests: amps-REQUEST@contesting.com
> > Problems: owner-amps@contesting.com
> >
>
> Hi Douglas this is a very bad idea. The IMD performance of any tetrode is
> dependant on good screen voltage regulation. The dynamic regulation of the
> plate supply is pretty bad and this obviously causes problems with screen
> regulation if a string of zeners are used. John Nelson GW4FRX wrote some
> excellent articles on this in the 80s.John frequents this forum so he may
> wish to comment.Meanwhile try this link for a solution
> http://www.ifwtech.com/g3sek/boards/tetrode/tetrode-1.htm and some
> background info.
>
> Regards
>
> Conrad Farlow G0RUZ
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/amps
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
--
Doug Snowden
Systems Branch
National Climatic Data Center
Asheville, North Carolina
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
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