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Andy,
As the 502.4 dial frequency looks to
be accepted , with other stations moving in to the
capture area when running wspr and as it would seem, AA1A is
monitoring this dial setting a frequency in the lower part of
the wspr section would ensue a clear frequency, activity looks to
be centred in the higher portion of the band ?
These look to be the first wspr spots , of
which I assume to be the 'first established permanent wspr beacon'
?
| 2009-09-19 12:06 |
G4JNT |
0.503855 |
-9 |
0 |
IO90iv |
0.2 |
G3XVL |
JO02nb |
212 |
51 |
| 2009-09-19 12:06 |
G4JNT |
0.503850 |
-23 |
0 |
IO90iv |
0.2 |
M0LMH |
IO93gx |
343 |
358 |
| 2009-09-19 12:06 |
G4JNT |
0.503850 |
-1 |
0 |
IO90iv |
0.2 |
M0BMU |
IO91vr |
119 |
39 |
Power wise , during daylight , your ground wave
looks to be simply a function of power , at -23 at
343 k with 100 watts ? , you could reduce by 10dB to 10 watts
and still provide ground wave data ? , in tests last year with
Rick ON7T , carrier levels below 1 watt still decoded at range.
I will up date the beacon page on uk500khz to
include the new mode
73 - G .
Sent: Saturday, September 19, 2009 12:06 PM
Subject: LF: 'JNT Dual purpose beacons
I'm in the last stages of modifying my beacon to include a
WSPR transmission that will run pseudo-simultaneously with the 15
minute regular one at 503.7kHz
It has turned out to be posible to fit all the code into one
controller PIC which simplifies the hardware considerably - the only downside is
that the PSK31 message length has had to be shortened by a few characters to be
able to get the additional WSPR symbol and frequency information into the EEPROM
area of the PIC.
I've included to option to be able to transmit the WSPR signal at a lower
amplitude than the 15 minute beacon, and the pseudo random timing is anything
but - it has been chosen to fit round the 15 minute intervals, and
preferably not adjacent to them.
Before I programme-up the actual beacon Tx, can I have some suggestion on
the frequency that would be best to avoid existing users, and what sort of power
to adopt, bearing in mind the main Tx runs at about 100 Watts of
RF giving somewhere in the region of 24dBm ERP. Also some idea of a
duty cycle to use - 50% is the maximum I've allowed for.
Andy www.g4jnt.comthis email has been scanned
for political correctness by the nanny state
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