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Re: (meteorobs) Re: Leonids '66
At 12:42 AM 11/29/97 -0500, Jonathan wrote:
[snip]
>... And, did anyone do any radio meteor observations during the storm--I'm
>guessing they didn't because no one knew that meteors left ion particles up
in >the atmosphere that would reflect radio signals, and radio waves and
>astronomy were only coupled in 1931.
I don't know whether the professional meteor observers carried out radio
meteor observations during the 1966 Leonids storm; but radio amateurs
certainly anticipated and took advantage of the storm, making literally
hundreds of two-way contacts during the several hours of the actual storm.
The quotation below is from "Beyond Line of Sight", an American Radio Relay
League (ARRL) publication edited by Emil Pocock and still available from
ARRL. The quotes below are from an article beginning on page 106 titled "The
Shower of a Lifetime", written in January, 1967 by the late Ed Tilton,
amateur callsign W1HDQ (he is writing about the 1966 Leonids storm although
he opens by mentioning the 1965 event):
""The World Above 50 Mc.," January, 1966, QST, makes it clear that the
Leonids of 1965 were the most exciting meteor event in 144-Mc. history, up
to that time. Between this report and advance publicity in the news media,
there was no lack of activity on the 2-meter band during the small hours of
the mornings of Nov. 15, 16 and 17 this year. Literally hundreds of skeds
were being kept from about 0700 GMT on, each morning, but they were largely
unproductive until after 0900 Nov. 17, when things started to happen in a
big way.
"By 1100, contacts were being made over distances up to 1400 miles, in
the whole area from the Plains States eastward. Later the mania was to
spread over the entire country, with stations in the central states hearing
both coasts. Bursts overlapped and strong pings were superimposed on almost
continuous weaker signals. Hundreds of contatcts were bade by calling CQ, or
by breaking stations when their skeds were completed, as most were in the
first minute or two of prearranged calls."
Sorry for the abundance of amateur "jargon" above; here are "translations:
"The World Above 50-Mc." was the title of the monthly column written by Mr.
Tilton for
QST, which is the monthly journal/magazine of the ARRL;
144-Mc refers to the frequency band, also known as the
2-meter band (FM broadcast is from 88 to 108 MHz; in 1967, frequency was
called "cycles per second", kilocycles, and megacycles, abbreviated Mc.);
skeds is shorthand for "schedules", which are prearranged schedules during
which two amateurs attempt to make contact;
GMT is Greenwich Mean Time, now called UTC or Universal Coordinated Time;
"pings" are what amateurs call very quick, short meteor reflections usually
lasting less than about 1/2 second, which, when they reflect a signal from a
transmitter, often sound like a "PING" (longer-lasting "pings" are known as
"bursts", or sometimes "burns");
"calling CQ" means that a station would issue a general call (a CQ) for
anyone who hears him/her to respond and call him/her back; and
"breaking stations" means that one station hearing another would call in
immediately without waiting for the other station to call CQ.
The first recorded amateur meteor reflection (called meteor scatter)
contacts between two amateur stations took place during a visit close to
earth's orbit by comet Giacobini-Zinner on 9 October, 1946. Meteor
reflections had been heard before, but it was not until then that amateurs
realized the practicality of the propagation mode of meteor scatter.
Hundreds of contacts are reported to have occurred on the 50-MHz band during
that night. The first 144-MHz two-way contact did not occur until the fall
of 1953, and then only after many months of effort. In comparison, today,
144-MHz meteor scatter contacts take place every hour of every day, often
using just the sporadic meteor background for reflections. I have a daily
15-minute-long schedule on 144-MHz with a station in Kentucky owned by
Shelby Ennis, callsign W8WN, during which we conduct tests using very
high-speed morse code up to 1600 words per minute. On average, we manage to
exchange sufficient information to consider the contact complete and valid
about one or two days per week. Each of us almost always hears more than a
dozen meteor pings and/or bursts during the 15-minute schedule; during the
last few days, in fact, we have each heard from 2 to 4 dozen pings/bursts,
or between 2 and 4 meteors per minute. This is a slightly-higher rate than
we had been hearing before the Leonids shower; during the weeks after the
Perseids shower and the Leonids, we usually heard only 1 to 2 pings/burst
each minute, with very few lasting longer than about 1 second. This week, we
have each heard at least one burst during each schedule lasting at least
several seconds. During the Leonids, we each conducted over a half dozen
schedules with other amateurs throughout North America; and during the peak
hours of the shower, bursts lasting several minutes were common, allowing
the astute ham to make several contacts during each burst.
If you would like more information, e-mail me; I don't want to tie up
MeteorObs with just radio meteor talk!
Clear skies,
SteveH