[Lowfer] It's BACK

[Garry Hess]

The unknown signal around 137.777 kHz is back tonight and no longer 
sending an up-down staircase. Tonight it's sending FSK with variable bit 
duration spanning 137776.5 to 137777.5 Hz, with gaps between the 
transmission bursts. Some of the bursts look like alternate up and down 
ramps. Both the F1AFJ and W5JGV grabbers show the signal.

I copied quite a few staircase transmissions last night but never did 
get a credible heading with my loop, perhaps due to transmit power 
changes during the transmissions. Tonight I got a crude indication that 
the signal is coming from my NE or SW. The peak seems to be around 
80/260 degrees (the loop antenna pattern is bi-directional) and the null 
is around 170/350 degrees. It isn't all that easy to pin down using ARGO 
QRSS30 because that mode is so darn sensitive --- 10+ dB fades still can 
look white on the waterfall. I've relied instead on Spectrum Laboratory 
set up bandwidth-wise to act more like QRSS3. I also have some SNR 
calculations programmed, though lightning bursts can play havoc with the 
numbers. Hopefully others with directive antennas can provide additional 
direction information to pin down the source.

73, Garry, K3SIW, EN52ta, Elgin, IL