[amsat-bb] Re: I just curious

Greg D. ko6th_greg at hotmail.com
Sun Jul 5 12:14:44 PDT 2009

I think actually that there was an early OSCAR that did run a same-band transponder, but it's not easy.  The problem is getting enough separation filtering between the receive and transmit so that the satellite doesn't hear itself.  Terrestrial repeaters use large mechanical filters ("cans") to do this, but these are impractical on a spacecraft that may be many times smaller than the filter itself.  Going cross-band makes that filtering much easier.

Greg  KO6TH

> To: amsat-bb at amsat.org
> From: kd8bxp at aol.com
> Date: Sun, 5 Jul 2009 19:06:54 +0000
> Subject: [amsat-bb]  I just curious
> This is probably one of those questions that has a very simple answer maybe something I wasn't thinking of. 
> On the FM birds how come the split is V/U or U/V?  Are there any V/V birds? 
> I mean if doppler doesn't effect the vhf as much wouldn't it make since to have some V/V?  Wouldn't have to worry about doppler anyways
> I know there is a reason, so I am curious that is all!
> LeRoy, KD8BXP
> http://www.HamOhio.com
> Sent on the Now Network� from my Sprint® BlackBerry

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