The LF Notebook (31) The LOWDOWN, Oct. 95 The Mailbag, News and Comments About LF Radio, Etc. John H. Davis, Box 367, Warm Springs, GA 31830 -E-mail: johnhdavis@aol.com -Fax/Answering Machine: (706) 672-0964 -Longwave/Part 15 BBS: 706/672-0360 At the sound of the beep, the notorious answering machine that's always listed at the top of this column may actually take your messages once again! The confounded thing has worked off and on--but mostly off-- since about March. At long last, there seems to be a better than 50-50 chance of it working for a while. If you need to leave word for me, the most reliable way seems to be fax, followed by the BBS and e-mail in a close race for second and third place. Way back around the last turn is the answering machine...but we'll hope it gains ground now. - See Spot run. Just as the last column was on its way, news came that the first sunspot of the new solar cycle has been identified. The little varmint is tracing its way across the sun's surface among what's left of its older half-brothers (and sisters?) from the cycle that's getting ready to bottom out. Now, to you and me, all sunspots may look pretty much alike. However, they carry a signature that establishes their lineage, as definitely as DNA identified the remains of the Russian Czar's family a few weeks ago. Not only do the numbers of sunspots wax and wane over the roughly 11 year cycle, but Ol' Sol's magnetic field varies with the same cycle and actually reverses polarity during the minimum. Sunspots are places where concentrations of magnetic lines break through the photosphere, so when this one came along with polarity opposite of its brethren, observers knew it was the proverbial horse of another color. While we are already low on solar flux and have many days with no spots to count, the minimum wasn't expected until late next year. It may actually occur during this coming winter, though. Some observers say a quick rise into the next cycle might be expected, given the sun's record over the last few cycles. It's also interesting to speculate that we may be marking a return to weather patterns of the early Seventies, largely because of the sun. The end of the African drought is what enabled the tropics to become so active this year, actually surpassing the late-60's/early-70's activity. It has long been observed that there appears to be a roughly 22-year drought cycle in much of the world. The possibility of a solar connection intrigued researchers, but there seemed no good reason for such a thing to happen every other sunspot cycle. What about the sun's activity could trigger a divide-by-two flip-flop circuit, as it were, in the earth's atmosphere? As it turns out, now that we can measure the sun's magnetic field, no flip-flop circuit is needed within our atmosphere. All that's needed now is some explanation of how the sun's magnetic field reversals possibly affect patterns of precipitation. We can visualize how the sun's magnetosphere and the earth's might interact. But that's presumably 'way out in space. We know solar eruptions bombard the stratosphere with enough energetic particles to cause significant warming, even expanding the outer shell of our atmosphere farther out into space. But this happens during each solar maximum. So, the exact hows and whys of the sun affecting drought remain a tantalizing mystery. Of course, now that we've noticed such things as red sprites and blue jets, maybe we will find their electrical link with the edge of space to be influenced by changes in solar activity. At the lower reaches of clouds, lightning provides a link with earth, and there is reason to believe the ability of clouds to unleash lightning is related to their ability to release precipitation. Thus, between our monitoring of natural radio and scientists' studies of the upper atmosphere, we may someday find it's literally true what I speculated here over a year ago. Lightning may well be our geophysical "cosmic connection." - Still more signal relaying? (Well, just a little.) In case you haven't seen a recent Ramsey Electronics catalog, it now carries the answer to one big problem with using the FM broadcast band to relay natural radio, or other LF signals, from an electrically quiet site back to one's home. Frequency drift from ambient temperature changes is enough to render many low power FM transmitter circuits unusable with digitally tuned FM receivers. The Ramsey FM-25 kit solves that problem by using phase lock loop synthesis to stabilize the carrier frequency. It should be as stable as its reference crystal. Of course, the downside to this approach is the possibility of digital noise escaping and being picked up by a LowFER receiver. This could occur at multiples of 100 kHz and multiples of 19 kHz. Shielding and isolation may be necessary in some applications, but at the lower frequency of natural radio signals, there shouldn't be any problem. It also incorporates a stereo generator, which may or may not be useful to you, but its apparent ability to tune in 100 kHz steps could help you fit in between standard channels if necessary to find a quiet spot. It's more expensive than Ramsey's other FM kits, but the case is included in the price. And, it works on 12 volts! This is a kit that could let you get yourself in trouble with excess radiated signal levels, so be careful. If you can find a quiet spot on the band, though, and a relatively unobstructed path, the chart in the manual indicates you should get pretty decent coverage within the legal radiation limit of 250 uV/m at 3 meters. Periodical Shelf - The October QST may be of interest to LowFER operators looking for a means to insulate the base of their antennas. "The Offset Multiband Trapless Antenna," by Robert Wilson AL7KK, is actually about a low cost multiband vertical antenna for 40, 20, 17 and 15 meters. However, his construction technique, particularly the base assembly, could be useful to us LF types. Adventurous antenna builders might even adapt his feedpoint insulation technique for the purpose of inserting a loading coil near the middle or top of the antenna. Worth looking into! - An article in the September 73 Amateur Radio Today entitled "Longwave-Plus DX Techniques," by Richard Q. Marris G2BZQ, offers two ferrite loop antenna designs and a box loop. One of the loops covers 140 - 450 kHz, while the other two antennas are for approximately the 140 - 510 kHz range. Mr. Marris also relates an experience in the 1970s, when he rode out Hurricane Bella in Atlantic City while monitoring a portable radio with a longwave band. As the eye of the storm passed overhead, BBC on 198 kHz came up out of the noise to full volume, then faded rapidly as the eye went on its way. - As if there weren't enough confusion over the powerline/cancer controversy, a news item in the October Scientific American indicates there's even more controversy now over the possible role of submicroscopic crystals of magnetite inside cells. Those crystals were advanced as one mechanism by which weak magnetic fields could interact with cells in laboratory cultures, as has been reported in some cases. Other labs, however, have been unable to duplicate the reported results. The magazine reports, "The idea of Atsuko K. Kobayashi, Joseph L. Kirschvink and Michael H. Nesson, which appeared in correspondence to Nature this past March, challenges the efforts many biologists have taken to detect and quantify biological changes using cell cultures." In their work, they and their colleagues found that such ferromagnetic particles are common contaminants in lab equipment. If the crystals attach to the surface of cells, they could conceivably cause mechanical vibration of cell membranes under the influence of AC fields. However, other researchers deny that explanation for the observed effects, and still others say it is not necessary to invoke ferromagnetic particles at all. The item makes fascinating reading if you're interested in the workings of scientific research. On To The Mailbag - Dennis L. Hoffman (25755 475 Ave., Renner SD 57055-6504) is a reader who really enjoyed beacon hunting this past winter, and looks forward to it again this season, hopefully with an improved antenna. He wrote in with a few questions, though, that someone may be able to help him with. First, could anyone suggest a good antenna tuner circuit that would enable about a 100 foot long wire to tune 100 - 540 kHz, or maybe even as low as 10 kHz? Second, "I recently purchased a like-new Austron Model 2021L shielded loop (made by Austron Inc., Austin, TX), tuned to 100 kHz and used specifically for Loran C. Has anyone experimented with this type loop by making it tunable over a broader frequency range? If so, I would appreciate details on the tuning method and comments on the performance of this loop." And finally, an historical inquiry: does anyone know who might have operated a LowFER beacon or similar transmitter from Colton, South Dakota, at one time? If you can assist Dennis with any of these, please write him, or phone (605) 332-8555. - Steve McGreevy (spmcgrvy@ix.netcom.com) has uploaded new sound files to the Longwave BBS, resulting from his early September trip to Alaska. He described witnessing a "fabulous" aurora in the Fairbanks area, and recording daytime auroral chorus. The files are zipped together in AK_VLF1.ZIP on the BBS. He says: "Oh, superb MW BCB DX there too, when there was not auroral absorption. Western Samoa on 540 boomed in to the Kenai Peninsula after local midnight on Sept. 10 and 11, not to mention Hawaiians galore, NZ, Australia, Russia, Japan, etc. etc." (Maybe the state's tourism board could use a new slogan..."Come to Alaska, the DX State.") The VLF information file Steve posted on the Internet (mentioned last month) was noticed by Richard McVicar of HCJB's DX Partyline, and I understand he may read it on the program soon. (By the way, I've been unable to access the World Wide Web site mentioned in last month's column. If you're inclined to try it yourself, notice that the address should have had a period after the letters "www" instead of a hyphen.) In addition to the Web site and the Longwave BBS, Steve's story was posted on the rec.radio.shortwave usenet group on the Internet. - Les Rayburn (KCA4TSI, Birmingham, AL; e-mail: lowga@traveller.com or phone: (205) 324-3900) is the former operator of LowFER XMGR in Kittery, Maine and later Cleveland, Tennessee. He says, "I'd love to get back into the hobby...I'd like to try a MedFER beacon this time. Any info, circuit diagrams, or kits info would be helpful. Also, I'd love to get e-mail from anyone interested in this subject." Les adds: "The XMGR beacon is still available for sale. It features the LF Engineering exciter with a crystal oven for stability and a Hal Murken final amp, all enclosed in a weatherproof container. It operated for almost three years straight without a hitch. I'd like to sell or trade for a MedFER beacon." - Cliff Buttschardt (W6HDO, LowFER C; Morro Bay, CA 93442) appre- ciated the comments by R. D. Marchant in last month's Top End column. He adds, "Another item you might find interesting is that the Coherent CW group here on the West coast will be putting signals on 1835 kHz and 183.5 Khz in a fashion resembling simulcast but with different ID's for ham and non-ham operation. This should be an interesting experiment in ten times differential frequency propagation!" - Darwin Long IV (DJL, 3472 Big Sky Drive, Thousand Oaks, CA 91360) sent word this month of his beacon on 188.920, perhaps the newest one in California. The ID is DJL, repeated several times in CW, followed by the QSL address. It operates nightly from 0500-1230 UTC. Welcome, Darwin. - Lyle Koehler (K0LR, LEK, MIN; Aitkin, MN) tried AOL e-mail this month, but lack of a local access number may make that impractical in the long run. "Daytime QRN levels are subsiding but at night it's still as bad as ever. Bruce is running BK all week now that the thunderstorm threat is reduced, SAM has been on fairly consistently, and RM was testing on Labor Day weekend. I haven't talked to Roger since last winter, so it's nice to know that RM is still operational. There are no changes to LEK and MIN frequencies. Both beacons are now running 24 hours a day." "Max Carter's recent article on the synthesized carrier generator sparked my interest. I'm slowly putting together the pieces for another LowFER receiver using Max's circuit for the local oscillator. If it takes as long as most of my other projects to complete, I'll be lucky to get it working before the end of this winter's LowFER season! I'm also glad to see Bill Bowers dispel the myth that a loading coil directly under the top hat won't work. My MIN transmitting antenna is built with a loading coil just below the top hat, and I believe that Walt uses the same technique on his widely-heard WI beacon." - R. D. Marchant (AA0RN, packet: AA0RN@IT9ICS.ISIC.IT.EU) checked in for the first time since last season. He has been bouncing back and forth between the U. S. and Italy the last year or so. The Army has cancelled his project there; thus, "I am now looking for work in the U.S. again so there may yet be an opportunity to get set up on 1750M. All depends on whether I can convince prospective employers that an ex 'military electronics expert' can be retreaded for the civilian sector." - A letter from George Clark (GEC, 1900 Alta West Road, Mansfield OH 44903) arrived just a little too late to make last month's column. He confirmed the address that I had found, but which was rather old, and said he continues to operate sporadically on 1750 meters, generally between 175 and 187.5 kHz. Like your columnist, George has experimented some around 8 kHz, in his case using 800 watts of audio power. He used a unique type of antenna, too, working a deep well casing ground against the utility company's neutral wire, at about 80 ohms impedance. "This wire runs along the power poles for countless miles," he notes. This could result in a mixture of ground dispersion, loop antenna with ground return, and/or extended longwire antenna. Whatever the principle, he says "I was easily able to copy my signal GEC at 45 miles with a homemade receiver. A man who works for Fair Radio Sales in Lima, OH, said he heard a Morse signal at 8 kHz, but it seemed to run together with the background noise." - Brice Anderson (BA, IE, W9PNE; P.O. Box 14, Lancaster, IL 62855) and his wife celebrated their 54th wedding anniversary on September 5. Congratulations! August was a rough month for for lightning at their QTH. (I believe it was about that time a year ago that the church where Brice is a deacon suffered some lightning damage as well.) One might be inclined to say "just ground everything in Lancaster during August," but--surprise--the antennas already were grounded. The rigs were disconnected and unplugged, but "fuses were blown in all my gear, the rotator for my TH5DX was zapped, and the IC-720A made deaf." That current must have been all dressed up with nowhere to go, to paraphrase the old saying! Fortunately, exercising the various functions of the 720A several times helped it recover its mind, and it now receives on all bands including LF. That, in turn, resulted in our first LowFER reception report of the season. Brice managed to copy YHO about 439 through "tremendous QRN." Beacon BA is back on 24 hours, following repairs. The final was in a metal roofed shed while Brice was mowing around the antenna base. A storm came up, and afterward the biasing diode was blown, though nothing was connected to the amplifier at all. (A strangely similar fate befell the MedFER rig, too, which was still under repair in early September.) As soon as mowing season is over, the 3,500 feet of LF ground radials will again be unfurled, hopefully enhancing the BA signal further. - Randy Lott (NR5K, 4009 Camino Dr., Plano, TX) is considering setting up an LF beacon in Plano. "I will use the exciter discussed by Max Carter in the August Lowdown. Can you suggest sources for the 'outside' part? I need plans for a simple PA and loading coil. My antenna will be a 30 foot vertical with a top hat. Any ideas?" - Ernie Marquez (West Palm Beach, FL) checked in on the BBS. "I have been interested in LW radio for several years and would like to get in touch with other experimenters in this band. I would like to know more about beacons. Maybe I'd put one up here. By the way, this (the BBS) is a nice way for LF radio enthusiasts to get in touch." If you'd like to reach Ernie, pending a more detailed address, contact him through the bulletin board. - Robert Laney (WB7PZU, Herndon, VA) is one of the especially thoughtful members who updated listings this month. His RL will soon be back on the air 24 hours a day. "I hope to get started soon on erecting a new tower, which will be better guyed than the one that was taken down last spring by the wind. I hope to be operating by mid to late October. Things like a fall vacation will pleasantly interfere some, but not too much. Over the summer I have monitored about a dozen frequencies for man-made noise and have selected a new operating frequency of At least this is a quiet frequency at this location as compared to some of the harmonics, etc., on some other parts of the LowFER band." - David Joseph (San Jose, CA) checked in on the BBS recently. He has been reading a friend's Lowdown, and may join soon. "I listen to LF and VLF here in San Jose on a regular basis and have a pretty good log so far. I use several types of receivers. So far my best is a Drake SPR4 (down to 150 kHz) and a Palomar L-101 converter to 80M for VLF/ELF (gets down to about 3 KHZ)." Much continued success, David. - Will Payne (N4YWK, Crossroads, GA) may be a new member, too, by now. He wonders if there are other members nearby. Crossroads is on the Yankee side of Atlanta...or, as Will describes it, 15 mi NW of Atlanta Dobbins AFB. "Have tinkered with 1750m since middle school. Have an old DZ-2 receiver and a Cushman CE-24 frequency selective level meter, both good RXs. Also have been doing high altitude unmanned free balloons, in the ham bands. Last N4YWK balloon was 28.322 and 146.575 MHz telemetry and 434 MHz video. Altitude 112,000 ft. Would be very interested in LowFER beacon in edge of mesosphere? There are some rumblings of support for another balloon launch. We (Atlanta Balloon-a-tics) are looking for donations and sponsors from local hams, foxhunters, and Southeast Airgas (for helium). Am planning a 184.32 beacon, about 200mW." Will is be interested in ideas for deploying a balloon-based antenna. On balloon experiments, he uses the BASIC Stamp, "which is a GREAT little computer/controller you can get for $19," as the master computer. He has uploaded some files for it. (They are contained in the file YWK_BCN.ZIP, which includes some details of the beacon, I believe.) "They have to do with using the Parallax BASIC Stamp for radio beacons/telemetry and such. This is a really versatile, easy and inexpensive way to get the job done! The Parallax software loader and app notes are not now shareware. There is an earlier shareware version, and I can upload it if you want. If there is wide interest I could provide custom programming of Stamps for LWCA members to use on their beacons." Will reports building "a 1750m transceiver with 20 memories, dual synthesized digital VFOs and an autodialing DTMF pad. With digital frequency readout, yet. Well, I sorta cheated. I used a VHF handie talkie and built a transverter. It transmitted fine, was not quite finished with the receiver when an unfortunate power supply accident ended its life prematurely. It was a really weird project...." Further information can be found in Will's posts on the BBS. This month has been a productive one for his receiving efforts. "My wife just doesn't comprehend why I sit in the basement for hours listening to that squealing, crackling racket, but I netted over 30 NDBs last night, including several new Canadians. I am now using a 40m horizontal wire oriented normal to an HV line about 2 miles behind the house. My receiver is a RYCOM level meter with C-msg and 100Hz filters. Indicated noise floor is -94dbm." The technique by which he detected whistlers was a little unusual. After three hours of hunting beacons, he was tuning the OMEGA range. "I tuned a bit lower and was awestruck! It sounded at first like someone twanging a taut rubber band. Tuning between the massive overloading hum below 1 kHz and the OMEGA above 9 kHz, I found I could listen USB with the C-msg filter passband centered about 2.6 kHz, and hear whistlers above a -63dbm noise floor of buzz and crackle. And what whistlers! They were coming in singles and in groups, maybe as many a 40 per minute, some head and shoulders above the ambient levels. They were one hop type and once a 'grunt' or 'croak' was heard." "I strongly believe the combined use of frequency conversion, BFO injection and high performance filters allowed me to hear the whistlers under what would normally be impossible conditions. In fact, attempts to receive unconverted audio all resulted in overload severe enough to paralyze the detector. The reception of unconverted audio still seems most aesthetically pleasing, and I am anxious to attempt it from Pigeon Mountain next month, with a McGreevy type receiver. Bet I'll have a tape recorder then!" He's also looking for a schematic and/or documentation for the older tube LF receiver, "a 'CRV-46152 of DZ-2' pre- or early WWII aircraft style, pre-octal tubes, external 28V dynamotor supply. Rig was working on home made DC supply, but now has intermittent open." Also, documentation for a Rycom Selective Level Meter: " I have two to repair for someone and hope to obtain at least one from him." If you have such information, leave word for Will on the BBS or drop a note to this column. - Dexter McIntyre (WA4ZIA) sends greetings: "I plan to have the ZIA beacon back in operation about mid November. Will again be on 189.000 kHz from EM95TG, a few miles from Stanfield, NC, 30 miles east of Charlotte. Looking forward to working the LowFER gang on 1750 and 160 meters again this winter." - David W. Spearing (KB9CSW; 910 Prospect, Portage WI 53901-1935) has some thoughts of his won on the 1750 meter ham band issue. "My first thought was that 1750 meters really should be a true ham band, but then I asked 'Is it really necessary?'" "I believe it was Ken Cornell who wrote several years ago that there are now vastly more electronic devices out there making noise than when the 1750 meter 'one watt and a 15 meter antenna' was written. I doubt there are many who would argue with this, and it is for this reason that he argued for an increase in power on the 1750 meter band. Indeed, something needs to be done to improve the situation, and the two most logical ways are to make 1750 meters a hame band, which would require some special restrictions and provisions; or, to make the current law more realistic in light of a changed situation." "It appears to me that the simplest and perhaps best compromise would be to amend the current S. 15.112 (a) to read 'ten watts' (I would prefer 25), and drop S. 15.112 (c) which deals with antenna length. If S. 15.112 (c) needs to exist at all, the phrase including transmission line in the 15 meters of antenna length should be deleted. These are simple modifications which would improve the hobby and should not meet with too many strong oppositions." "In short, let's improve it, not Ham it." Your news and views are welcome here too. Til next month, 73. - - -