The LF Notebook The Mailbag, News and Comments About LF Radio & Other Experimental Topics John H. Davis, PO Box 367, Warm Springs, GA 31830 -Fax/Voice: (706) 672-0964 -E-mail: johnhdavis@aol.com -Longwave/Part 15 BBS: 706/672-0360 April showers bring...a lot more aggravation than some parts of the country need or want. I hope our West Coast readers are drying out by the time this reaches you, and that the rest of you will be enjoying this early Spring that has sprung Down South, which we are earnestly trying to export in your direction (while holding onto just a little for ourselves; sort of a commission, you might say). As we begin a third year of this present column, thanks are due to all who contribute. Special credit goes to our unofficial but indispensable "regional reporters," those folks whose names appear here regularly, and who bring us word of more activity in their home areas than I could possibly dig up on my own. Apart from these thoughts, I shall refrain from any monologue this month, in favor of a couple of topical notes and the Mailbag. There will be plenty of space this summer for feature material, most likely. I'd like to leave room this time for more of the other technical articles that made last month's issue so interesting...and maybe (if Bill determines there's enough room) a not-to-be-taken-seriously article by a fictitious colleague of mine from the local newspaper. More Longwave On Line Last month we mentioned the spring schedule for the Longwave BBS (Friday evening through Monday morning, plus random evenings during the week), and longwave topics on CompuServe's HamNet. This time, Robert Kramer (N9MBK) has initiated an effort to spread the LF word on America Online. "I am attempting to get a Longwave Message Board going on AOL. It will cover all aspects of low frequency DX and operation. I hope to see beacon, whistler & lowfer info out there. Spread the word. To reach the message board, go into the ham section, then select message board icon. (The longwave topic) is listed under Shortwave." The Future of LF And MF Interference? It was announced in mid-February that the FCC is proposing to permit manufacturers of computers and peripherals to market equipment without having to apply for equipment certification and await FCC approval. Presently, digital devices undergo either certification or verification, depending on their class. (That, in turn, depends partly on whether they are intended for home or office use.) Both count on the manufacturer to make measurements prescribed in Part 15. In the case of verification, the FCC doesn't ordinarily require submission of the data or an equipment sample, and doesn't issue any authorization per se. Verification applies to Class A devices, and all Class B digital devices except home computers. Home computers and peripherals must presently receive FCC certification. Certification requires that all measurement data and a detailed description of the product be submitted to the Commission for review. In addition, motherboards, cases, peripherals, etc., often have to be tested both individually and in combination. According to an ARRL bulletin on ET Docket 95-19, "The certification process can take 35 days or more, the FCC said, and eliminating the wait could save the computer industry some 250 million dollars a year, the industry has said. The FCC called the current regulations 'particularly burdensome for small manufacturers' and said its proposed new authorization procedure would 'align' FCC requirements for personal computers with those 'used successfully in other parts of the world.'" Manufacturers will only have to submit a Declaration of Conformity, and that can be based on tests of individual pieces, not necessarily the whole product. Will this be a boon to conscientious small manufacturers, or will it be too big a temptation for others to cut corners? We, as LF enthusiasts, may be in a position to find out (the hard way) long before general consumers of electronic goods do. The Mailbag for April '95 - One of the new beacons this season has a name and address associated with it now, thanks to a letter from Todd Roberts (ABC). LowFER NI is operated by Bill Murr, 1918 Savannah Highway, Charleston, SC 29407. Some of our correspondents already have heard NI, and Bill would appreciate any reception reports. - Eric R Mildebrath (ERM; St. Cloud, MN; CFWK82A@prodigy.com) reports a change of ERM's beacon frequency: "It now is 181.25 kHz. It is not on the air as much as I'd like because of antenna problems." - Rick Warnett (P29KFS; Port Moresby, Papua New Guinea) recently renewed, and says of The LOWDOWN: "We (the Port Moresby Radio Club and I) have received it without fail, a reflection on the mail systems between our two countries. It has always been one of those sought-after envelopes in the mail box, and it's always been read on the same night no matter what the time!" Rick cites news on "upward lightning" and articles on BPSK techniques as being of great interest. He also mentions, "you have an increasing number of international readers, who really appreciate the continuance of home brewed gear and original investigations." (Correspondents here at home say much the same thing. Authors and would-be authors, take note! Your efforts are welcome and appreciated.) In addition to his LF activities, Rick is a six-meter enthusiast, and is intrigued by the possible relationship of upward discharges to sporadic -E. "Any explanation would be a real revelation of what has always been 'black magic.' Although the ability to predict sporadic-E would be great, I think there are still enough uncertainties in its occurrence to make that actuality unlikely." Rick sees BPSK as a way to expand horizons for LowFERs, within our present power and antenna limits. "We have practical limits of antenna systems, but our power limit is 10 watts." Of course, practicality is not always the final word in radio experimenting. He notes, "As I wrote once before, we have a great river canyon that would be ideal for the installation of a halfwave dipole on 186 kHz!" - Robert Laney (RL, WB7PZU, 3153 Southfield Drive, Herndon, VA 22071) says LowFER RL has been on the air pretty much 24 hours a day since the first of the year. "I had started out on 186.59 KHz but now RL is on 186.69. Fred Larrick (FL) called me a couple weeks ago and we had a nice long chat about beacon activity and he provided me with some helpful information. He was able to copy RL, but I had difficulty in copying FL because of fairly high noise levels here." "Fred pointed out that significant power company noise about 188.6, and he suggested that I warp the crystal-controlled frequency. I was able to shift the frequency to 188.67. Earlier this week, he was able to copy RL much better. After I improve my reception techniques, Fred and I hope to have a QSO." "On Sunday , 1995, I took my ICOM 735 and LF Engineering active antenna and headed west from Herndon, Virginia on Route 7 to test RL for distance. I was able to hear it at about 30 miles." Other results of this trip are in On The Air. Robert offers this suggestion: "It would add some interest in this section of the publication for those reporting signal reception of beacons to give their approximate mileage to the beacon." - Ron Barlow (N4GJV) writes, "QRN has been severe most nights as a result of the relentless series of frontal system spawned storms that have plagued us this year. OVO/N3 was heard on Feb. 2 at 0453 Z, and faded out soon afterward. Due to the late hour, I was unable to continue listen for its possible return." "ZIA was a mystery at first. However, a guess and a telephone call confirmed its QTH. It was a pleasant surprise to learn that my friend Dexter, WA4ZIA is an LF enthusiast in addition to being a UHF/microwave enthusiast and experimenter!" - Robert J. Fear (IA; 225 North Boots, Marion, Indiana 46952) observes, "Looks like the ranks are increasing. I stopped by my local radio part supplier and mentioned the LWCA. One of the owners has been a ham for almost 45 years. Couldn't believe that people were using longwave again. Said he would give it a listen. I plan on dropping off a copy of the LOWDOWN." - Doug Williams (OER) reports his LF beacon OER will be taken off the air for the season on April 1st. "East Tennessee is starting to become very Spring-like, and my wife and I are looking forward to the warm weather. I hope to do some antenna improvements on OER this summer and hopefully will be back on the air around October." (Thanks, Doug, for the kind words on the H. John Clements award and the columns, too.) - Great news from the Beehive State this month...Utah will once again be represented on 1750 meters, after a few years' absence. Pete Smith (K7ZTM, 627 W 1800 North St., Layton, UT 84041) announces the commissioning of beacon Z on 183.500 kHz. Mode will be CW, and the transmitter has both crystal control and VFO capability. Operation is expected to be 24 hours/ 7 days, and reports are welcome. Pete says "It's unique in design," and promises us a picture of the station when it's on the air. - Cecil Wadford (RED) called and wrote to say he is off the air while "moving to a new location with more antenna space and away from high power lines." (These are the best reasons your columnist can think of for moving, too, but I haven't found such a place yet in this area.) When RED returns, the mode will be BPSK. "I have been on with BPSK, with no BPSK receiver," he notes. However, he has almost completed work on a Max Carter convertor design, and should have suitable receiving capability soon. - Sam Eastey (SAM, IMG) checked in from a location far south of Minne- sota to say that SAM discontinued operation temporarily, as of February 10. "I received a call from a fellow ham who was working CW on 40 meters, and he was copying my beacon S9+ on 7190.054." It poses something of a mystery, for Sam notes, "I do have a low pass filter between the final and antenna...unless the filter itself is resonant at 40 meters." He will likely have both SAM and IMG on soon. This is a good reminder to the rest of us to check our signal purity from time to time. It is definitely possible to have unexpected series resonances in filters and tuning networks. And solid state output stages certainly generate an ample supply of harmonics. (Even tube circuits had enough variables to make life interesting. I was just reminded of my first MedFER transmitter back in the mid-60s; both the tank and the antenna had an extra resonance at 11 meters, giving me about 15 miles range in AM mode on the Citizens Band...far better that it did at MF! Like Sam, I was fortunate in being tipped off by a friend.) - Rick Wright (R, KA5YWH; Durant, OK) has had an eventful winter, and a busy spring with a heavy teaching load. He reports operating the R beacon weekends, and hearing it easily 40 miles from home. At the time of his letter, he hadn't yet been heard at Bill Bowers' QTH, though. He himself hears TEXAS when monitoring at a quiet site about two miles from home, and has been listening for OK. Rick indicates noise levels appear higher this year, and thinks beacons might have gotten through if better conditions had prevailed. He also reports some broadcast band carriers mixing in his preamplifier, overshadowing weak signals. "The AM band skywave can come in even near noon around the winter solstice," he reports, and skywave from WOAI was strong an hour before sunset even in early February. Rick has been working with LORAN and ADF gear (more on this in a future column), an interesting proximity detector that uses LF (diagram and information on this next month), and a project that is at the other end of the spectrum altogether. "I've been using a Hewlett-Packard high-intensity LED (non-lasing) to transmit regular video to a wide bandwidth (25 MHz) H-P silicon detector. It works nicely and could be a respectable video link with a range of a mile or two line-of-sight when astronomical telescopes of 8 - 10 inch aperture are used to beam and recover the signal. With telenegative lenses and 10-inch Newtonians, the beamwidth can be as little as 0.3 degrees, which brings about an awesome amount of gain. The H-P diodes are really bright, and can be made to couple their power efficiently to the telescope optics; they're competitive with lasers. I note that the idea of using light beams to send video goes back to the 20s, during the very beginnings of TV, and fiber optic links are coming into their own today." Telescopes may need warning labels, though. "Astronomy has its special hazards: falling from telescope platforms, malaria (it has killed a few astronomers!), freezing to death, hypoxia....I've added a new one: pneumonia." An astronomy class for non-majors and a session for a church youth group, coupled with frigid weather and a bad cold, caused him to spend three days in the hospital this winter! Til next month, 73. . . .