Hi, Jim.
I'm copying your beacon OK here at 20:30z
Measured signal levels (signal path includes a tuned pre-amp) are:-
beacon -63 dBm, -69 dBm, -77 dBm, -83 dBm, and the last dash is below the
noise level of -85 dBm.
The set up is a Mini-Whip on top of a 2.4m portable mast, tuned pre-amp and
SPM-30 with 1740 Hz bandwidth.
Intriguingly, the signal strength is much the same if I use my regular
transmiting 20m long "Tee" antenna at 5m instead of the MiniWhip.
If I turn my ADSL modem back on, the noise level jumps to -73 dBm.
What level of carrier power are you putting into the antenna?
73, Dave G3WCB IO91RM, nr Windsor, S.E England
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of James Moritz
Sent: 09 June 2009 20:48
To: [email protected]
Subject: LF: M0BMU small antenna test beacon
Dear LF Group,
As art of continuing investigations into antennas, grounds, etc., I am
running a beacon at the moment on 503.5kHz - I am testing a small "/P"
antenna similar to what G3CWI proposed to use a couple of weeks back. It is
a 9m high "umbrella" with 4 x 5m long top loading wires sloping at about
45degrees. Ground system is 4 x 20m radial wires.
The beacon is transmitting an 8wpm CW identifier, followed by five 5 second
dashes at reducing power levels in steps of 6dB. The maximum ERP is
somewhere in the region of 100mW ERP. The sequence repeats every 2 mins
roughly.
I'll leave it running until after dark at least - any reports would be very
welcome.
Cheers, Jim Moritz
73 de M0BMU
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