[Hearsat] Re: [MilCom] 254.2 Activity

[David I. Emery]

On Fri, Feb 02, 2007 at 06:52:06PM -0500, David I. Emery wrote:
> 	FWIW, I just took a look from near Boston Mass at 254.2 with a
> 12 dbi crossed yagi surplus milsat beam aimed at around 30 W and I very
> clearly see a standard 25-30 KHz wide transponder there with its noise
> floor at least 10-15 db over the thermal noise (reads around -130 dbm in
> a 1 KHz RBW).   It is notable that the center frequency of the passband
> of this transponder is 5 kHz low (eg 254.195 rather than 254.200)

	Looking in peak hold mode I see someone or something keyed up on
exactly 254.2000 with a fairly narrow signal  (looks consistant with AM
aircraft traffic) at a power level I would expect from a signal relayed
through the transponder (around -112-115 dbm).

	Not clear whether this was a local aircraft using this frequency
in my area (near Boston) or something coming through the satellite.  
There certainly ARE UHF ATC users on downlink frequencies from time to
time - not clear whether the guys that assign UHF operational freqs have
lists of the satellite channels  or even care about them - but if it was
satellite relayed it was quite strong.


-- 
   Dave Emery N1PRE,  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."