[amsat-bb] Community Survey Request -- crosslinks, multi-hop packet, and satellite DX

KO6TZ Bob my.callsign at verizon.net
Sun Apr 2 22:54:54 UTC 2017


Zach,

I like what I see so far on your initial proposal.

In the past, I have been involved with 2-HOP and 3-HOP packet attempts 
using various combinations of the ISS, NO-44 and NO-84 when they were 
all working on 145.825MHz.

Your proposal of using a 9K6 FSK 2-port_digi's on board three satellites 
in the same orbital track resolves what I believe to be the main 
challenges we faced in our 1200 baud experiment.  If the footprints 
overlap, the satellites should be able to talk to each other.

1)  Since the satellites were in different orbits, there was Doppler 
shift in the signal between them.  In your proposal, doppler is minimal 
for FM packet.

2)  With your 2-port digi, the repeated packets between satellites will 
not be interfered with by multiple up link signals. Improving the 
success rate.

3)  I find that 9K6_FSK is as easy to copy as 1200baud, so efficiency in 
channel usage is gained.

Once the operators acquire confidence in establishing basic 2 & 3 Hop 
packet contacts, the other experiments and distance records you 
mentioned will follow.

I'm in.....

BOB
KO6TZ


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