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

Re: The S-band ĘsewerĘ

At 05:51 PM 7/27/2006 +1000, Geoff wrote:
>Hi Guys,
>    Just throwing up a ¨what if¨. Given that the amateur 2.4 GHz 
>allocations are getting so crowded/polluted, how would a coded spread 
>spectrum downlink on Eagle cope? I don´t have the professional 
>background to do the performance numbers. I am an aircraft mechanical 
>systems guy :-) .
>    73 de Geoff vk2tfg


That might be more immune to WiFi interference (someone else would need to
check the numbers), but this does not solve my issue of what to use my
current radio equipment for.  Well my dish-preamp-downconvertors would
probably work but it would require a completely new spread spectrum IF
radio (and that probably would be an SDR doing freq hopping and demod in
sw).  Probably just as cheap to make a complete 2-GHz spead spectrum
receiver (but that is one more thing to purchase).

If I am to purchase new (or convert surplus WiFi) I would rather do it on
mode-S/C or for the original C-C Rider.

All this debate on mode-S is not going to result in Eagle providing
anything.  Obviously they have ruled out mode-S downlinks (still I question
why telemetry is mode-S, then?).  All I can conclude is that the psk
telemetry signal is more immune to WiFi interference.  But that would lead
one to suggest digital voice for mode-S downlink (do you see the circular
reasoning? - best just do mode-S/C as they are planning for). 

I will resurrect at my new QTH my mode- UV plus LS tracking system to work
P3E and maybe some Leo ssb birds.  I will be ready for Eagle mode-UV.  It
will remaing to be seen what developes for mode-S/C and what the ground
station costs.  The new Eagle physical design looks better for the power
budget...that's good.

This is my last comment for now.  Let's read what the design team presents
over the next few months and ponder that.  I'm sure this subject will be
debated more later as the picture is in more detail.
Ed - KL7UW  
http://www.qsl.net/al7eb - BP40iq 
144-EME: FT-847, mgf-1801/1402, 4xM2-xpol-20, 170w
432-EME: FT-847, mgf-1402, 1x21-ele (18.6 dBi), 60w
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org