Reading W3ZZ's QST bit about Eskip detection reminded me of a post I
made a few years ago to the local vhf group's list. I would be
interested in seeing if people much further from the transmitter can
hear it or hear the echoes.
Here it is:
I have been interested in real time meteor detection. There are
several ways to do this - one very often suggestion is to listen to a
TV or broadcast FM transmitter and listen for the pings. Several
years ago in searching around on the net for information on ways that
others have watched for meteors I found that he US government runs a
system that they use to track all of the things that orbit our planet.
Naval Space Surveillance System or NAVSPASUR transmits a CW signal on
216.98 Mhz. The transmitter site is in Lake Kickapoo, Texas (Archer
County) - west of Fort Worth, Texas. This transmitter puts out 768 kW
ERP. The antenna is an array of inverted vee dipoles above a ground
screen - so the energy is going up.
You can read all about the system here - including photos:
http://www.zilker.net/~crossley/NAVSPASUR/index.html
also see
http://www.fas.org/spp/military/program/track/spasur_at.htm
Recently I got my 222 Mhz yagi up and I finally had an antenna that
worked near 217 Mhz. If you have a radio that will tune CW/SSB at
216.98 Mhz you are all set. I use my Downeast Microwave 222 Mhz
transverter and I just tune my HF radio down to 22.98 Mhz. The gain
is down but the transverter is broad enough to work just fine for
hearing the NAVSPASUR signal. I can hear their signal well at all
times of the day or night. As meteors or satellites pass over the
site you get to hear their reflections of the signal.
If you have any of the sound card programs that have a waterfall type
display of audio frequency over time you can "see" the signals of
objects as they pass through the transmitter beam.
You can see some of these sorts of displays on this page along with
links to all sorts of information on this subject.
http://science.nasa.gov/newhome/headlines/ast22dec98_1.htm
If you have a radio that you can tune down to that frequency - give it
a try.
--
George Fremin III - K5TR
geoiii@kkn.net
http://www.kkn.net/~k5tr
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