Isn't there some authorized amateur activity in the 600 meter band? I saw someone post that they had a beacon going aroun 500 khz.
Dave W7AQK ------------------------------------------------------------ The FCC issues special experimental licenses for various reasons. These are not "Amateur Bands" or frequencies assigned to the Amateur service. The longest wavelength "Amateur Band" remains the 160 meter so-called "top band". About ten years ago a group of mainly ex-Maritime operators, most of them Hams, formed the "600 Meter Research Group". Their interest was in whether it was feasible to make use of the very stable, predictable short-haul propagation on those frequencies for land-based emergency communications by Radio Amateurs. The 600 meter wavelength equates to 500 kHz in frequency. That's the old maritime emergency frequency for CW distress calls. The challenge was in whether it was practical to erect a workable antenna on a typical suburban lot. Any antenna fitting on a typical lot would be very small, electrically. After all, at 500 kHz a simple half wave "dipole" is nearly 1,000 feet long! Ships used very tiny antennas, electrically, but had the advantage of sitting on a huge salt-water ground plane. About six years ago the 600 Meter Research Group (600MRSG) won approval to transmit on certain frequencies. That lasted only a few weeks before the US Coast Guard (USCG) realized the FCC has authorized the work and demanded it be shut down (US Government agencies take precedence over civilian licenses issued by the FCC). We learned that here in the USA those frequencies were reserved by the USCG for short-range beacons to provide Global Positioning System (GPS) correction signals that will allow accuracies of a few inches. With the increased interest in automatic landing systems for large aircraft based on GPS and the need for high accuracies, it's no surprise those beacons are largely slated for installation at airports all around North America. Certain frequencies in that range are also still used for SOLAS (Safety Of Life At Sea) purposes, such as the Navtext automatic weather reporting system. Since then the ARRL also has sponsored work on very limited frequencies in the 600 meter band, winning an experimental license from the FCC in 2006 for limited transmission by specific Amateurs under the experimental call sign WD2XSH (see http://www.arrl.org/news/stories/2006/09/15/104/) It is clear, however, that the US Coast Guard has firm plans for that part of the spectrum that will prevent any significant assignment of frequencies to other services, including Amateur Radio. Very low frequency experimentation has gone on for years by various experimenters with unlicensed equipment that qualifies under Part 15 of the FCC rules in the number of Amateurs have won experimental licenses to operate between 160 and 190 kHz, and others have done some work at about 136 kHZ under special part 5 FCC rules. The ARRL tried to obtain a "sliver band" for Amateurs at 136 kHz but was turned down in 1998. There's a lot of information on the web. Plug LOWFER into your favorite search engine. None of the Elecraft rigs tunes those frequencies directly, although the K3 is spec'd to 500 kHz. That's no real surprise. The circuit components needed for efficient operation below 500 kHz are very different from HF, just as one can't simply scale a 40 meter rig up to 144 MHz using the same components and end up with a high-performance receiver. Up-converters are fairly simple to build and a number of designs are commercially made that work very well with a high-performance HF rig. In additional to the experimental stuff, there's occasional interesting signals in the 600 meter range. For example, a few of the old coastal CW/RTTY maritime stations are still on air for special occasions as "museum" stations. One of them is station KPH in California, which is run by a private group of dedicated ex-operators and Hams. See http://www.radiomarine.org/kph-proj.html Their special broadcasts are also made on various frequencies in the HF spectrum that are readily monitored by the K3 receiver without any special converters. And some countries still have ships at sea using CW on the maritime band, although their number is quickly dwindling. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
