[Premium-Rx] Re: FCC

[Peter Gottlieb]

If this works anything like the SARSAT system I wouldn't worry too much.

The SARSAT (Search And Rescue Satellite Assisted Tracking) system uses a 
series of US and Russian LEO birds to pinpoint 121.5 and 243 MHz (406.25 
MHz is the new system, different engineering) distress beacons.  Now 
consider a few things.  These birds are in elliptical orbits, random to 
your location, so if someone is interested in your signal the nearest 
bird might be at a poor angle to get good accuracy on your location. 
Also, such a doppler system only works with certain signals, for example 
it is VERY difficult, if not impossible, to use reliably on SSB.  Even 
if you have a great lockable signal the merge will only put the fix 
within maybe 12 miles or so (ha.  More like 20+ at times).  A 12 mile 
radius circle is a lot of area to search!  But it can tell the truck 
where to go.

Now, I am familiar with how doppler DF works and have seen some very 
interesting, obviously VERY premium receivers with this capability built 
in but don't know who makes them.  Systems I have seen have components 
made by WJ and a company called I think Microtel (didn't have a long 
look) plus some others.  I guess this stuff doesn't make it to ePay very 
often.  Does anyone know more about this?  I would really like to get my 
hands on something that would work on HF, my main interest being QRM 
location, specifically in regards to BPL.  I would like to be able to 
document real interference and track it to specific systems.

Peter


Ben Dover wrote:

> After a web search on WHITE CLOUD and reading the Federation of Concerned 
> Scientists item on the system, paranoia set in; for months thereafter I was
> EXTREMELY careful about the language I used on the ham bands!  ;o)