It's great to see the CODAR move out of 60m, but I didn't realize that some channels were available for ham use!
I wrote to Josh Kohut a few years ago to complain about CODAR interference to tropical band stations. Thought you might like to read his very nice and informative response:
Andrew,
Thanks for your interest in the site. We at Rutgers operate 4 systems
along the New Jersey coast, one site on Block Island, and another on
Nantucket Island.
A few years ago when we started operating these systems we had some
communication with several shortwave radio listeners who asked that we try
and avoid the 60-meter band. At that time we had four sites all operating
at different frequencies between 4.4 and 5.2 MHz. The shortwave listeners
that we spoke with had the same request as you, to stay below 4.8 MHz. So
in our applications to the FCC we applied for frequencies below 4.8 MHz as
well as the 4.8 MHz band. We kept the 4.8 MHz band in the license because
that is a frequency that the FCC has asked to use in the past.
Since that time CODAR Ocean Sensors (the manufacturer) has developed some
new hardware/software that allows us to operate many sites at the same
frequency, without any interference. This is great for everyone because the
4 frequencies we were occupying for four sites reduced to one frequency. It
uses GPS timing (pretty cool stuff).
Up until this past summer we were able to operate all of our four sites in
New Jersey at 4.55 MHz and the two sites in New England at 4.47 MHz (well
below 4.
, taking advantage of the GPS synchronization. This changed when
the FCC instructed us to discontinue our use of the 4.47 band and switch to
another frequency. Our only other choice in the license was the higher
frequencies (around 4.8 MHz). So we had to move the sites in Block Island
and Nantucket to 4.8.
We are only one out of several groups around the US (including Gulf of
Maine, Gulf of Mexico, San Diego, Monterey Bay, and the Gulf of Alaska) who
are operating these systems. I am not sure how many of these other sites
are operating with frequencies in the upper 4 MHz region. The interference
in Texas could be from any of these stations (including us).
These stations are being used by a diverse user group including us (the
geeky scientists), the Coast Guard, NOAA Hazmat, local police, k-12
education. Because of the large user base, these systems are beginning to
multiply along the coast. With this large number of systems being deployed,
there is a need for us, as a community, to explore primary bands with the
FCC. These bands would include frequencies that you suggest (4.4-4.7 MHz).
This way we can't be kicked off like we were last summer. This is a long
process, we have to go beyond the FCC to the ICU for approval.
Our intention is certainly not to interfere with your transmissions. We
have tried in the past and will continue to try to work with shortwave
listening community so that we can both operate without interference. If
you have any more questions, please do not hesitate to ask.
Regards,
Josh
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