Drove by that LF antenna array in Dixon back in '02. Very impressive
antenna farm out there. Lots-O-Wire and towers.
----- Original Message -----
Sent: Wednesday, October 05, 2005 9:17
AM
Subject: LF: Re: 135.92 warning
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
