----- Original Message ----- From: <[email protected]> To: <[email protected]>; <[email protected]> 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 _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
