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RE:(meteorobs) 24h Draconids monitoring
-------------------- Begin Original Message --------------------
Message text written by INTERNET:meteorobs@latrade.com
"Tom, have you tried listening for television transmitters, either the
amplitude-modulated video carriers or the frequency-modulated aural
carriers? And, are you using a directional yagi antenna? If so, do you have
it elevated or pointed at the horizon? The difference will be that if it is
slightly elevated, you will probably obtain some additional directivity
because you will be tilting the antenna's pickup pattern away from
transmitters that are located on your horizon. In addition, by tilting the
antenna upward, you will be listening for meteors that are *above* your own
horizon, and thus are closer to your station; this has the added benefit of
reducing the signal strength loss because the distance from your antenna to
a meteor trail and down again to a far transmitter becomes shorter. For
forward-scatter, signal strength is proportional to the square of the
distance so that atmospheric loss can decrease considerably rather quickly.
You might also try the FM band while elevating your directional antenna;
the elevated pickup lobes may shift far enough over a close-in transmitter
that it does not normally interfere with listening for meteor-scattered
signals.
My last suggestion concerning the FM band is that you make certain that
your receiver is not picking up the same station at two points on the dial,
which is caused by a design deficiency in the receiver to cut costs. If so,
then you should try to use a tunable filter to reduce the number of
stations that you can hear at one filter setting.
I have also heard of folks listening for the VOR beacons at airports which
are located at the very top of the FM broadcast band from 108 to 116 MHz, I
believe. Of course, you would have to check that the beacon of interest is
left running 24-hours!
Clear skies,
SteveH
Shrewsbury MA"
-------------------- End Original Message --------------------
Steve,
All good advice above.
Unfortunately, I don't have a radio for tv carriers. I have attempted
meteor reception with regular tv sets but haven't had much luck in limited
trials.
My FM forward scatter array has been very fine and sensitive over the
years. There was a time when I worked four separate radios with four yagis
and had the antennas fanned and overlapping so that I could often hear one
meteor pass through all four lobes in time as it reflected in transmitters
on four different frequencies. I eventually settled into using two radios
and recording into a stereo VHS recorder. Also strip chart recorded for one
year 24 hours a day.
My best stable frequencies used to be 91.1 MHz and 91.9 MHz. Now there are
local stations there. From Santa Fe I work northeast out over the Great
Plains and due east to the Ozark Mountains. I get meteor scatter from North
Dakota, Minnesota and Wisconsin. Also Arkansas and Illinois to my east. I
spent hundreds of hours counting meteors under headphones and logging
stations. It is pretty interesting science to be sure. Though somewhat
addictive.
From Santa Fe, I have radio monitored and correlated the "new peak" of the
Perseids with Werfried Kuneth and others in Europe and also a professional
radio meteor observatory in Japan. The Perseid radiant was above the
horizon for each observer and each observer saw a distinct activity
enhancement over a span of some minutes. The corroboration over such a vast
distance of the planet was very satisfying.
Clear skies,
Tom Ashcraft