John, The 75 Hz RTTY centered on 73.6 kHz is not a continuous
transmission. I have heard it every day this week around 2200 UT. It
produces a reading of -30 dbm on my selective level meter (tuned loop
with preamp) when the normal noise level reads -75 dbm.
My assumption that the signal originates from CFH came from this page:
http://www.provcomm.net/pages/joe/introvlf.htm#Target
If you do not hear it strong we need to find another possible source.
Stewart, I have a .wav file of the 73.6 kHz signal. It's one minuet
long and is close to 1 mb. Will send it to you if you would like to
analyze it.
Dexter
John Andrews wrote:
Stewart,
> Also, is the following about the FSK signals correct?
> On about 73.6 kHz is CFH (75 Hz shift and 75 BPS)
> and on about 73.3 kHz is Rugby (100 Hz shift and 100 BPS).
I have only seen listings in The Lowdown for CFH being on 73.6. They
certainly haven't been there in the last week, as the signal would be
overpowering here in Massachusetts.
The center frequency for Rugby is 73.25 as seen here, and the signal is
exactly 100 Hz wide. It is a few dB stronger here tonight than it was at
this UTC time on Tuesday.
John Andrews, W1TAG
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