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Eclipse Monitoring at Malin Head,
Ireland.
The following is a very
non-tecnical monitoring of various frequencies during the period of the Eclipse,
today 11th August 1999. Receiver ICOM R75, Antenna, my LF 136
khz antenna, untuned.
I tried to find a number of
stations south of my qth, but rather than range over a wide frequency, I
picked
one LF station, and the rest in the
Medium Wave band. Broadcasters running relatively low power.
1. The LF station was
the power house on 138.8 khz. Starting at 0915 utc as the base line, this
station
remained stable until approx 1020 utc when its signal came up by
about 6 db, then dropped back to
its
normal level by 1035 utc.
2. One Medium wave
broadcaster in Ireland on 540 khz , which is 250 km to the south was
chosen as
its
signal is extremely weak here, its supposed to be a 2kw rig but sounds
more like 100 watts, even
driving by in its service area its very weak. The effect of the Eclipse on this
signal was a nothing at
all,
even listening on up to 1100 utc. Surprising, but there you go, that's how it
was here.
3. Three broadcaster
were chosen at the top end of the Medium wave band, 1602 khz BBC
Radio
Kent, 1521 khz Fame 1521 Reigate/Crawley, and 1476 khz
County Sound Radio , Guildford.
All
three transmitters run low power, ie, 1602 khz 250
watts, 1521 khz 1000 watts and
1476
khz 500 watts. There were very definite effects on these signals,
particularly 1603 khz.
1603 khz up to 1005
utc nil heard, however at 1007 a Spanish broadcaster
suddenly came up and
by 1013 utc was an s8/9 signal, very strong. By
1025 Radio Kent started to come up under the
Spanish station, with a distinct fluttery signal and the Spanish station
dropping rapidly down to a low level
in the background until 1030 utc when Radio Kent took a sudden dive
down to almost nothing. The two
by now very weak signal mixed with one another for a about 3 minutes until
1035 utc, by 1036 the
freq was dead. NIL. The most noticable effect was on Radio Kent,
whose signal , although quite readable, yes they too were nattering on about the
Eclipse, was the fluttering effect on their signal, rapid and although their
modulation was good the carrier never got above about s3.
Checked 1476 khz and 1521 khz from 0915 but not a trace of them.
1476 khz and 1521 khz. at about 1004 both signals started
to appear. By 1018 utc 1521 khz was
an s6 , at 1019 1476 khz was s7, by
1023 utc 1521 was up to an s9, but 1476 khz was almost
nil. Both station took on this effect of rapid qsb, up and down from almost
nil signal to at best s9, by
1028 utc 1476 khz was running a very good s7 up to 1031
utc , but at 1035 utc 1476 khz and 1521 khz were both
dead and stayed that way. There was no fluttering effect on either of
these signal, just rapid and very deep qsb.
Whilst tuning down to 1521 khz I noticed a s9
signal on 1575 khz from a Spanish station at 1008 utc and again at
1018 utc, an s8/9 signal.
As far a the visual effect of the Eclipse on our location, yes it did get a
bit darker, much like when a heavy rain cloud appears, but nothing very
dramatic, mind you it was very cloudy, so no sight of the Sun.
The garden birds seemed to ignore the whole thing, I certainly did'nt
notice them fluffing out their
pillows or putting on their electic blankets for a quick kip.
As far as I can see from my atlas, those top end Medium wave broadcasters
are about 700 km from my qth. From an LF viewpoint , there was a very
definite increase in the 138.8 khz signal of about 6 db's
not quite as much a the effect on this signal under normal nighttime
conditions when it goes up about
10-15 db's here.
Best regards
Finbar EI0CF
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