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Re: AMSAT has a SECRET: why not 10m instead of V band



29 MHz is not without its problems but has the big
advantage that everyone can receive it using simple antennas.
Lets face it a 13cm downlink, valuable though it is,
will only be received by the truly dedicated satellite
enthusiast. It will not attract new people into satelite
operation.

Unfortunately having lots of available bandwidth on the
microwave transponders is of little use if you don't have
the stations to fill it. 

I have long wanted to see more Mode A satellites with
a 10W pep 150 KHz B/W transponder in either
a 1500 Km or preferably a 4500 Km orbit.
Getting launches into such orbits is clearly a problem
but not impossible.

Trevor M5AKA

--- Jon Ogden <na9d@speakeasy.net> wrote: > Leslie,
> 
> The biggest problem with a 10m downlink is the bandwidth of
> the passband.
> 
> The 10m satellite sub-band is quite small.  The S-band
> downlink sub-band is
> much larger (I am not sure how much).  If you try to link
> something like L
> band to 10 m, you will only be able to use a very small
> portion of the
> uplink passband.
> 
> This is another reason why 2m is rapidly losing favor as a
> band of choice
> (although I personally would like to see it stay for the next
> bird or two)
> for HEO satellite work.
> 
> AO-40 has a 10m downlink because it was going to have a 2m
> uplink.  Come to
> think of it, the HF bands haven't been tried on AO-40 yet, so
> we could do 2
> up, 10 down and I think the IF matrix could even connect them
> separately
> from the U/S and L/S combinations (I am not positive, but I
> think it could).
> 
> Your idea does have a good thought at heart.
> 
> 73,
> 
> Jon
> NA9D
> 
> on 6/1/01 10:41 AM, sco@sco-inc.com at sco@sco-inc.com wrote:
> 
> > I might do away with a 2m link in favor of a 10m downlink
> capability. That
> > way any ham or SWL who has a general coverage receiver
> 160-10m will be able
> > to hear the satellite. Once they hear it they might get
> interested and want
> > to talk thru it too. I would suggest that more people 
> (hams and SWLs) have
> > a general coverage HF receiver as compared to an all mode
> VHF receiver.
> > They are less expensive to buy too.
> > 
> > A 10m downlink could be heard well on a dipole antenna.
> > 
> > Make a satellite in an AO-40 orbit (that was planned).
> > With 10m and S band downlinks.
> > With U and L band uplinks.
> 
> 
> -------------------------------------
> Jon Ogden
> NA9D (ex: KE9NA)
> 
> Member:  ARRL, AMSAT, DXCC, NRA
> 
> http://www.qsl.net/ke9na
> 
> "A life lived in fear is a life half lived."
> 
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> AMSAT-NA.
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