Re: [amsat-bb] AO40 modes

["Edward R. Cole" <al7eb@xxxxxxxxxxxxx>]

>From: Estes Wayne-W10191 <W10191@motorola.com>
>Jeff Kelly wrote:
>"it looks" like AO-40 may be primarily a 1.2 up and 2.4 down bird
>Wayne replies:
>Why do so many people say this????
 
Lots of good comments so far to Estes question:

And of course it is not limited to mode L/S as far as is known about the
status of the satellite.  But a cautionary thought:  so far only telemetry
has been sent via the S2 transmitter.  As far as I have heard, no test of
the analog transponder matrix has been conducted, so do we know if we can
connect the L-band receiver to the S-band transmitter.  Same goes for the
the V and U receivers.  It is encouraging that commands are accepted and
the other receivers are passing tests, so hopefully the rest of the
interfacing matrix works?  

So if it does, then it makes sense for modes U/S and L/S.  If the 2m
receiver works then I guess V/S.  As far as the 15m and 10m I do not think
they should ever be connected to 2.4G downlink.  It is my belief that those
two HF bands were added to provide operations with 2m for the folks who are
"beginner" or entry-level satellite operators.  I'm afraid with the demise
of the 2m Tx those bands are not particularly useful.  Why?  Well think
about having the "world-wide whatever contest" on 15 or 10m being replayed
on 2.4G?  In my opinion that is a flat waste of satellite!  I know some of
will think me mean-spirited for stating this.  Of course mode-A could be
used if the V-band receiver is working.

Here is what I expect if nothing else has failed:
Main mode = U/S for all the reasons already given.
Mode L/S because it is a natural for small antenna set ups
[apartments/mobile/portable/restrictive neighborhoods].
Mode V/S because it is there [but infrequently activated]
Mode L/X and L/K if we have them [for experimenters and the future of
satellite communications]
Mode S/X and S/K [ditto]
Mode C/S, X, K [same reason]
Mode A [V/?] depends on power budget [I would expect not frequently]

I think the last three lines will not be used much.  Modes V/X and V/K will
not be used for the same reason that V/S is not likely: 144 is commonly
used as the Rx IF.

P3E is our hope for replacing AO-10.  And of course this is one ham's
opinion...time will tell.

Ed
HF-50-144-432-1296-2400-10368 [& maybe 24G]
Getting ready for VS-US-LS-UX-LX



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