George and all:

Yes, this entered my mind as a possibilty --- IF there is antenna space available within the current design, and IF it will be electronically compatible with the other receivers and transmitters since the cuurent design objective is to have all tranponders simultaneously active. This requires a fair amount of RF interference analysis (RF blocking, intermods, desensing, as well as overall antenna pattern analysis) since all the various antennas occupy a small "real estate".

Bob points all this out previously, so that would be a question an effort to build a TSFR s-band transponder will need to ask the design team. In particular I wonder how the mode-s receiver in the S/C "rider" system would coexist with a full-time s-band Tx? Honestly, I would make such a prospective as one that would have a "ON/OFF" command...in other words the mode-S downlink package could be toggled off by command stations should it turn out unusable.

If there is sufficient folks and money to support such an independent project, I would suggest hiring established transponder engineers to do the actual design and construction...i.e someone known and respected by the "Amsat family". Afterall, such a module must satisfy all the spacecraft requirements and testing to qualify to be included and flown.

If the team could accept this project as one of theTSFR modules then what is the time-line for accomplihing this. As a former NASA microwave engineer and Project Mgr., one does not take these tasks lightly.

OK I await comments. 73's Ed - KL7UW

At 01:09 PM 9/9/2006 -0500, George Henry wrote:

So, how much to rent one of the TSFR spaces? Maybe all of us who still believe in S-Band could pool our funds to fly our own transponder..... fund the mode instead of the bird?

----- Original Message ----- From: "Rick Hambly (W2GPS)" w2gps@cnssys.com To: amsat-bb@amsat.org Sent: Saturday, September 09, 2006 5:21 AM Subject: [amsat-bb] Eagle Satellite Design

<snip> > > c) There are at least two TSFR (This-Space-For-Rent) packages that could > possibly contain other RF or other payloads, conditioned on the > availability > of power, antenna space and compatibility with the primary payloads.

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73's, Ed - KL7UW ========================================= http://www.qsl.net/al7eb - BP40iq 144-EME: FT-847, mgf-1801/1402, 4xM2-xpol-20, 170w 432-EME: FT-847, mgf-1402, 1x21-ele (18.6 dBi), 60w =========================================