[amsat-bb] Re: Question about vacuum and power module for lineartransponder

[i8cvs]

----- Original Message -----
From: <G0MRF at aol.com>
To: <pe1rah at yahoo.com>; <amsat-bb at amsat.org>
Sent: Saturday, December 19, 2009 9:01 PM
Subject: [amsat-bb] Re: Question about vacuum and power module for
lineartransponder
>
> Hi William.
>
> A better solution would be to build a class AB linear from 2 suitable
> FETs. An even better solution but one requiring a lot of development
> would be to separate the modulation into phase and amplitude and then
> modulate the gate with  phase and drain with amplitude. Efficiency >80%
>
>
> David

Hi David, G0MRF

What you suggest is the HELAPS principle of Envelope Elimination and
Restoration that was used in all linear transponders from OSCAR-6 ,OSCAR-7
OSCAR-10 and OSCAR-13 with an efficiency of about 85 %

http://www.amsat-dl.org/dl/HELAPS_en.pdf

The above is a complete description of the HELAPS principle written by
Dr. Karl Meinzer DJ4ZC with all functional schematic diagrams of the
linear transponder Mode-B on board of OSCAR-7

I hope it helps William PE1RAH

73" de

i8CVS Domenico