[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: S-band receiving requirements



Wayne, et al.

I didn't read that article and I'm not familiar with the example so I
will take your word on the numbers. I agree that a new baseline RX
requirement needs to be established but we must first wait until a
closer to final configuration of the bird has been established. We need
to know if we are going to get 3D stab, if the solar panels can be
safely deployed and what the offpoints are going to be. That will depend
on whether the perigee can be raised enough to reduce the effect of the
perigee drag torque.  We will also need to know if the momentum wheel
system will be available to do quick (relatively) repoints, and what the
strategy will be for deciding on where/when to point the antenna's in
the satellite footprint.

I do agree that maybe some kind of advisory should be posted on the
websites that a better S band RX T/G is presently needed due to the
birds configuration.

A small helix and a surplus converter is not going to cut it at the
moment....
That has been safely established, IMHO.

Vince
KD7AI


> Wayne replies:
>
> Yes, your setup is good enough.  But your setup is much better than
what numerous articles claimed would be good enough. Your setup has 3 dB
more antenna gain and half the noise figure compared to Example #1 in
P3G to P3D that was claimed would get 23 dB S/N.
>
> Any volunteers to write an article called "What you REALLY need to
hear AO40" to replace the misinformation that is currently on the amsat
web sites?


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home