-----Original Message-----
From: measures <2@vc.net>
To: Conrad Farlow <conrad.farlow@virgin.net>; Douglas Snowden
<Douglas.R.Snowden@noaa.gov>
Cc: AMPS <amps@contesting.com>
To: <amps@contesting.com>
Date: 10 April 2001 19:06
Subject: Re: [AMPS] MLA2500 and screen voltage for 4CX800.
snip
>>http://www.vcnet.com/measures/D.a.08.GIF is the circuit to use off Rich's
>>pages. He also has a stack of zeners off the plate supply on another
>>page.Please don't do this.
>>
>It was not Rich's idea. Eimac recommends a shunt screen regulator for
>smaller tetrodes. I used the circuit in two amplifiers and dynamic
>screen V regulation was better than 1%. A caveat: Operate zeners at no
>more than 33% of rated dissipation.
If I remember correctly, the measurements made by GW4FRX (and/or G3SEK?)
showed a significant improvement in IMD if screen regulation was improved
from around 1% to around 0.1%. That's not the same as saying that 1%
regulation produces unacceptable results in the real world, but shouldn't we
aim for the better target? The effort of building a better screen supply is
usually minor compared with the rest of PA building.
Steve
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|
