As much as I hate to say it, that probably was not the AMRAD beacon. It is
really at about 136.745 (we are assigned 136.750 but the tolerance
specified allows us a few HZ either side). Also I watched it for a while
with ARGO set to 120 sec mode and there is a noticeable cyclic frequency
variation as the heating system cycles. We plan on running it with 90 sec
dots for a while.
Sandy
WB5MMB
----------
From: john sexton[SMTP:[email protected]]
Reply To: [email protected]
Sent: Tuesday, February 06, 2001 4:14 AM
To: [email protected]
Subject: LF: Is this the Amrad Beacon??
Hi All,
I used Argo last night to monitor the Amrad Beacon frequency at 136.750 kHz
and found a signal precisely on frequency to within 0.01 Hz. I used the
highest resolution of 120 sec dots, which means that one cannot see the
QRSS
coding, which is probably 3 sec dots, but the signal could probably not be
seen at all if I had set Argo to that dot length. I used the Loran lines to
calibrate Argo.
To see the best image click on www.g4cnn.f2s.com/amradbeacon.jpg. The
signal
is about 0.01 Hz low in this picture, but when I recalibrated Argo this
morning, I found the nearest Loran line at 136751.5669 also appeared 0.01
Hz
low, so this is just a calibration error (still learning).
The signal was visible from about 22.00 last night (010205) until 06.00
this
morning when it died out.
I saw no clear "Dawn effect" on the QRN in these images, but the QRN is low
throughout, which might be a result of using this resolution, or perhaps
the
different frequency.
In order to measure to 0.01 Hz accurately, I had to import the images into
Paint Shop Pro and use the vernier to measure the difference in position of
two consecutive 1 Hz marks and the line. The lack of finer vertical scaling
in Argo is the one minor deficiency in this otherwise excellent package.
Thanks Alberto.
73, John, G4CNN
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