[MilCom] satellites

[David I. Emery]

On Thu, Jun 04, 2009 at 02:27:47PM -0400, jeff wrote:
> If I have scanners that are good to at least 2G, am I likely to receive 
> anything worth hearing or is this more specialized with a dish, decoding 
> software, and a complex preamp?  I have a serious discone and a generic 
> preamp that does the job for everything, as well as a separate HF 
> antenna.  I get the shuttle on 145.8 when it comes over.
> 
> I have checked online and found plenty of freqs, largely 250+MHz and 
> 15xxMHz FM but haven't heard anything yet.  I know loss is a problem the 
> higher you go in frequency.

	Satellite signals are weak, you will need a decent GASFET LNA
and probably also a directional antenna - a 3 foot or more dish for L
and S band, and a beam or helix or surplus UHF Milsat antenna for 260
Mhz milsat.

	However all these signals are mostly digital these days, there
are few analog signals on Milsats - mostly Brazilian pirates in
Portuguese - but an occasional in the clear US military transmission does
show up. Not many or often, but it does occasionally happen.

	L band (Inmarsat and GEOS and Iridium) is now ALL digital and
without some more or less unavailable software you won't be able to hear
much of anything at all.   GEOS weather satellite software IS available,
however... but the hardware required is more than just a scanner.   All
of this is more sophisticated than all but a very few hobbyists... not
just a tune the scanner to a signal and listen situation - though in
fact the actual hardware required (Small dishes, LNAs, DSP interfaces to
scanner IFs (SDR radios)  and s fast PC) is pretty readily available 
now and what is missing is the software to interpret the complex
signals. Some ARE encrypted, but not absolutely all of them ...


-- 
  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."