Hi all,
Since yesterday, ~ 17 UTC, i'm running a new portable experiment on 970
Hz, or the 309 km band. The receiver site is somewhere in the forest in
JN49BK, a distance of
40 km to the TX site.
I carried a lot of accus to that location and the USB stick where the
data is written on has 64 GB, so i can run the experiment for more than
one week! :-)
For the first time i'm using two antennas. An active E field antenna
with a 1.5 m long steel wire as the capacitive probe. It is mounted on
a 10 m high pole. The E field preamp is supplied by a separate battery
and uses an isolation transformer with a low pass filter applied.
The second antenna is my compact loop with 80 cm diameter and 84 turns.
It uses a low noise preamp (also supplied by a separate battery) using
a LT1028. This loop RX worked surprisingly well on 4470 Hz when beeing
in France last September. Hopefully it will pick up the signal.
Unfortunately the E field antenna is not very high above the
sourrounding trees, so the sensitivity may be limited. Also the H field
antenna showed much more mains hum than expected in this location. So
it may be a bit questionable if the experiment will be successful. The
long transmissions will allow to stack carrier transmissions and/or
EbNaut transmissions though...
Running 36 mA antenna current means an ERP of 10 nW on that
frequency.
My transmission plan is:
30.JAN, 17 UTC: Carrier on 970.005 Hz
01.Feb, 17 UTC: Carrier on 970.0025 Hz
02.Feb, 17 UTC: EbNaut, 16K21A, 2 char, 100 sec, CRC22 (24 hours)
03.Feb, 17 UTC: EbNaut, 16K21A, 2 char, 100 sec, CRC22 (24 hours)
04.Feb, 17 UTC: EbNaut, 16K21A, 5 char, 80 sec, CRC17 (23:49:20)
05.Feb, 17 UTC: EbNaut, 16K21A, 5 char, 80 sec, CRC17 (23:49:20)
Not sure if someone else can pick up the signal. Most likely not. But
new components to rise the voltage to 20 kV in a next experiment are
already in preparation...
73, Stefan
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