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John & the group
Interesting you should mention this. I've been
plotting NPG the past couple weeks ala W3EEE DCF39 style graph. The
signal is quite strong typically showing up at 0100Z and fading out an hour or
so after local sunrise. The signal is strong enough that the frequencies between
.925 and .975 become filled with 'white' on an Argo screen. In order to get
to a truly clean noise floor for the noise channel measurement it was necessary
to move at least 25 kHz outside the carriers.
Had been planning to make this into a 'permanent'
upload for propagation study in the next week or so...if there is any interest.
A contact at DOD verified it as Dixon CA
running 40 kW.
Jay
----- Original Message -----
Sent: Wednesday, October 05, 2005 9:32
AM
Subject: LF: 135.92 warning
The area around 135.922 kHz has been used for Europe to North
America
transmission for several years. In May of 2005, a military TTY
station in
California started using that part of the band. Following a tip
from
Laurence last night, I noticed that the signal is quite loud in the
eastern
U.S., and was clearly audible an hour after sunrise this
morning.
They are using 50 Hz shift, with carriers on 135.925 and
135.975 kHz. I
don't know what the keying rate is, but the signal is
appropriately wide.
Any of you planning transmissions to North America
should consider moving
above 136 kHz if this operation continues. Since the
east coast is subject
to interference from CFH on 137.00 kHz (+/- a few
hundred Hz), there may be
an upper bound. Mercifully, the CFH operation is
intermittent, and they have
been quiet since mid-summer. With a number of
U.S. and Canadian beacon
stations running 24/7 in the 137.777 kHz range, it
would also be advisable
to stay below 137.5 kHz.
John Andrews,
W1TAG/WD2XES
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