The LF Notebook #37 (April 1996 issue, The LOWDOWN) The Mailbag, News and Comments About LF Radio, Etc. John H. Davis, Box 367, Warm Springs, GA 31830 -E-mail: johnhdavis@aol.com -Fax: (706) 672-0964 -Web http://users.aol.com/lwcanews/lwcanews.html -Longwave BBS: 706/672-0360 This is spring time? Maybe. The QRN alone should prove it, though the thermometer certainly doesn't yet. There has been a fall-off in reception reports of LowFERs this month, and at first it seemed there was a smidgen less news. In a way that's OK, because your columnist has been kept busy at work by the severe thunderstorms. But it's not a trend anyone would want to see continue. Fortunately, you kept those cards, letters, and e-mail messages coming in! Thanks. *Update On The Web Unbeknownst to me when I announced our World Wide Web page last month, Ralph Brandi, the Webmaster for the Association of North American Radio Clubs (ANARC) and our sister club, the North American Shortwave Association (NASWA), was also working on a home page for the LWCA. Ralph is quite experienced at this sort of thing, and I'll be more than glad to work with him on coordinating and integrating the two efforts. As he says, "I think combining the two would make for an even stronger page for the club." Rhe two pages are now linked. You can access the Longwave Home Page at the address at the top of this file. But also be sure to check out http://www.anarc.org/lwca/. For that matter, if you'd like to view home pages for any of the 17 ANARC affiliated clubs, simply start your search from http://www.anarc.org/. From the many comments received since last month's announcement, it appears there's great enthusiasm for our WWW presence. Even with the space limitations on files, some correspondents simply prefer Web access to BBSes. Several also mentioned that it's far easier for overseas members, and curious non- members, to reach a Web site. Thanks for all the remarks and suggestions. * Longwave BBS Schedule Of course, there was also a great deal of encouragement to keep the BBS available. Some members don't live near an Internet service provider, and many appreciate the larger archive it is possible to store on the BBS. The board's future is therefor as secure as anything can be these days. It will be going on its summer schedule beginning this month. Weekday hours will be roughly dusk to dawn, Georgia time. It will be on all day Saturdays and Sundays, weather permitting. Storms may result in brief shutdowns. (I found out this month that if I don't shut it down in time, power glitches can cause the software to look as though it's still working, but it won't answer the phone line for days at a time! That's very embarrassing. I discovered that when I tried to call it myself. Oops.) Please note: Up to now, there has been no formal registration procedure for using the bulletin board. During the month of April, though, I'll be asking BBS users to download and complete a brief questionnaire. (Filling out and sending in the Computer Communication Survey in this issue will also serve as registration.) You won't have to fill out the questionnaire to keep using the BBS, but unregistered users will have to log in as new users each time. It will be a great time saver to become a registered user, so I encourage our BBS friends to do so during April. * From The Mailbag... -Clifford Buttschardt (C; HDO;W6HDO; Morro Bay, CA) says "I especially appreciate Lyle's article (March issue) as it shows that the right kind of ham transceiver will also work well (for BPSK)." Cliff observes, "Wow! I did not think that I was going to have to build some sort of remote link to the site this soon in the game!!" What prompted that observation is the March 3 message he forwarded from John West (e-mail: lwave@indra.com): "I awoke at two AM and did some grabs (of 9) on your signal. Low background noise, excellent reception from 2 'til nearly six A.M. I got the other 9 possible start-bit combinations off the air, the reception was so good. If you had been sending messages I could have copied them easily. That's something I hope you can do soon. I will be working on my antenna today and hope to complete everything but the loading coil. I'll then measure the capacitance and do final CAD modeling of the loading coils, then build the coils, indoor work, so the weather will not be a problem. Only a few more days to go I hope." In addition, Cliff reports on some "SUPER good news!! We can at least start using BPSK on the ham bands." Cliff had asked the ARRL's Jon Bloom about the legalities of BPSK on 160 meters, and was advised, "There is nothing wrong with BPSK on 160 m. What you cannot do there, however, is operate an automatically controlled (unattended) beacon station." Cliff adds, "I wrote Jon Bloom back asking if other ham bands can be used and does it matter if the speed is non-standard (such as the one character per second we use on LOWFER)...will advise!" -Brice Anderson (BA, IE; Lancaster, IL) reports February was a better month than January for LF, and about the same for MF. He feels the season may be drawing to an end, though, with high QRN, compounded with sporadic bursts of power line noise whenever it's windy. On LF, BOB was heard quite often, and Bob heard BA, but no QSO yet at the time Brice wrote. YHO moved up 100 Hz from the previous spot, and has made reception better in Illinois. Both LEK and BK came in on a couple of days in early February, and he logged TH and ZIA as well. In the middle of that month, WI and KRY were heard. And it was February 6 when BA was heard by Jim Hagan in Malabar, FL. Brice observes that solar activity was low and the geomagnetic field was quiet that day, with flux of 71, and the A and K indices at 2 and 1, respectively. On the MedFER band, Brice was hearing STLMO day and night. Day reception was during brief fade-ins, about 15 minutes apart. At night, SEA was heard a couple of times, along with VA and MIN on Feb. 7, a good day for MF work. PX was the best of the DX beacons, he notes. Brice plans to run the BA beacon all summer, but expects to have the IE MedFER beacon off. It sustained considerable damage during the winter, and he plans for a better antenna next season. - Lyle Koehler (LEK, MIN, K0LR; Aitkin, MN) modestly says he has "been trying with mixed success to copy BPSK signals from MAX and HDO with my home-brew receiver and a MAX800 prototype from John West. The biggest problem has been interference from my computer. Yesterday (Mar. 12) I took a portable 4-foot loop with an isolation transformer and hung it in my wood- shed, about 80 feet from the house. I still pick up hash from the computer but it's not as strong as it is on my old faithful (but non-isolated) 8-foot loop. "The printout (next page) was obtained just before 6 AM today. The receiver was John West's MAX800 with the isolated 4-foot loop in the woodshed and a 'Univer-sal' pre-amp in the house. Copy was solid with the frame grabber set to 15, and was about 50 per cent before invoking the frame grabber. MAX was amost solid copy without the frame grabber a few minutes earlier. My home brew receiver and the IC-706 were also able to pull in both MAX and HDO this morning. It seems that the IC-706 (with a preamp in front of it, of course) works slightly better than either the MAX800 or my home- brew receiver. Meaningful receiver comparisons are difficult because conditions change during the time it takes to switch from one receiver to another and re-acquire the signal. It might help if there was a BPSK signal from less than 1000 km away -- HI. "Not much other news as the LowFER DX season winds down. YHO sneaked through between the power-line carriers last month and became the 20th LowFER signal logged here this season." -Michael C. McCarty (4708 Beacon Hill Road, Columbus OH 43228) would like to know if anyone has been monitoring the ELF band and encountered any- thing that could be the High Frequency Active Auroral Research Project, outside Gakona, Alaska. He describes it as a project in the testing stage. "It transmits an RF charge into the ionosphere on ELF frequencies. Its transmitter is reportedly tunable." He aks, "If you or anyone has heard what they think is HAARP, please send me any and all details. These are pulsed or steady carriers (non- voice). Also, if you have heard any voice in that range or farther up into HF that may be connected to HAARP, please include this also." Michael indicates he will send additional information on this intriguing project, and I hope he will include word on how to obtain their test schedule. A significant part of the effort is apparently to determine the effect of ELF energy on HF propagation, so it would be interesting to compare HF propagation before, during, and for a few hours after HAARP tests. -Stephen McGreevy (RR; e-mail: spmcgrvy@ix.netcom.com) draws our attention to another project involving RF injection in the upper atmosphere. The Russian INTIMINS project achieved some results in February, and he under- stands that more tests from the Mir space station are scheduled in April. For information, check NASA's Project INSPIRE page on the World Wide Web. It's available through the Longwave Home Page, and we'll try to get details on the BBS if possible. Steve went to London in mid-February, with side trips to Scotland and Wales. But it wasn't all just sight-seeing and plates of haggis. "The trip was to master a double-CD, entitled Electric Enigma, a set of my natural radio recordings to be released this summer by Irdial-Discs in London! It was FUN!!!" "This CD set has 2 booklets, a 33-page booklet with 'The VLF Story' in it, as well as photographs of my in-the-field receivers. A second book- let explains in detail about each track presented." This CD is due out around June 1996. For further information, contact: Irdial-Discs, PO Box 424, London, SW3 5DY, UK. (Fax: 44+171 351 4848) Their e-mail address is: irdial@irdialsys.win-uk.net. This dual CD set should find a place on the shelf of anyone interested in natural radio phenomena, and will be eagerly awaited. If you have already heard some of the computer WAV files of Steve's recordings, you know their quality. The CDs should be even better, and more comprehensive. They'll be a good excuse to go buy a CD player if you don't already have one. -Will Payne (YWK; Dallas, GA) continues to explore the world of very big loops and very tiny frequencies. He notes, "This is the truest science! Others may follow later, with big grants....but we are already here, on our own, not for fame or fortune, but simply because we thought outside the envelope, and took up the challenge of following our ideas. Folks, it just don't get any finer than this!" On Feb. 19, Will reports: "Just got a temporary preamp built for my two acre loop, and bought a Radio Shack digital volt meter with RS-232 output. The dvm sample rate limits my UPPER receive freq to 0.5 Hz. Need sharper filters for 60 Hz anyway, but thats next step. I am getting weak signals in the band from .1 to .01 Hz, not as strong now as near sunset. I can imagine at least five different noise mechanisms to fake it, but good chance at least some of it is real. Amp is DC coupled, using high gain, slow decay integrators made from LM1458s. DC drift is present but have not needed a DC trim in last six hours. "Wrote QBasic code to convert Radio Shack's dvm reading logs into .wav files, speeded up times 11,025. The Radio Shack disk includes two tools (DOS and Windows) by two subcontractors with different file formats, and is poorly documented. I can translate both formats, but poorly documented protocols prevent me from talking directly to the dvm. "My first .wav file is about one second played back, not much to go by. Sounds almost like someone shuffling cards. Gram 2.3 seems to show a diagonal mesh looking structure, but again its just a first peek thru a tiny crack into the unknown. Hope to have a longer sample by morning and get offline before t-storms come in, but my integrators are 62% saturated and don't know if they will last the night. The next day: "The integrators didn't last the night, saturating before dawn, but the six hours of good data make a two second audio wave. Sounds like rough, heavily muted static. Gram 2.3 shows three impulses near the end, no matter what settings used. I wrote code to differentiate the .wav, to make up for the heavy integration in the preamp. Now sounds more like ordinary static, but the triple impulse still stands out. The triple impulse is spaced about 310 sec and 220 sec apart, or about 0.004 Hz rate, and occurred near 0215 EST on 02-19-96. "Could the triple impulse be a seismic event signature? Seismic waves propagate in three modes with each mode travelling at a characteristic speed. Hope to get a record of seismic events occuring very early on 19-Feb! Might be just random noise or coincidence, but gathering clues and solving mysteries is the sport!" March 2: "The triple impulse did not match the three seismic wave speeds, but still looking for a 19-Feb seismic record to find a possible match there. Meanwhile, tore down the whole setup for major upgrades." "Also found out Radio Shack sold an older dvm with RS-232 port which came with source code in BASIC and documentation of all the commands the dvm supports. This disk is not currently available from Radio Shack, and you will not get any technical help from them." (We will check into the legalities of distributing this information in the near future.) "If a dvm with a PC interface sounds like a good idea to you, be assured it is one of the most versatile items you can get. But if you want to do more than admire it sitting on a shelf, either get the documentation from the discontinued Radio Shack disk, or buy from someone besides Radio Shack. Keithley, Fluke and others have similar products and they don't have the attitude of a former pantyhose marketeer." -Robert Laney (RL) reports his beacon "is now on the air after being off for a couple of weeks. I shut it down one day when thunderstorms were possible. I had started the season with a new 8-inch loading coil about which I had great hopes. But, several weeks ago I tested the signal for distance and found the results far worse than with a makeshift coil that I used last year. I have been experimenting with new coils. The one that I am using now consists of a wooden thread spool as a base and an ajustable ferrite rod. When hooked it to a dummy load, it had about a 25 percent increase in antenna current over the previous coil that I had been using.. With the new coil,there is a noticeable increase in signal strength on the S-meter of the ICOM 735, so I hope that the signal is reaching out a little farther. Who knows, one of these days someone may hear it." "I have a technical observation/question about antenna loading. When I tune up the antenna I use a clamp-on ammeter (Lowdown, April 1994), a DC voltmeter and ammeter on the input to the amplifier, and a field strength meter that I built a number of years ago for the HF bands. I notice that when the antenna current and the current into the amplifier are the greatest, the field strength meter is at or near its lowest reading. And when detuned, the reading on the field strength meter goes up. Is it likely that the field strength meter's band width is such that it is sensing a harmonic? I can't remember anything about the band width of the field strength meter. If it is sensing harmonic energy, it adds additional information when tuning the antenna. If this is what it is doing I shudder, because last year before I built the clamp-on ammeter I used the field strength meter to tune the antenna!" Robert would appreciate our thoughts on tuning procedures. For my part, I use a combination of methods, because in the near- field of an antenna, it is possible to draw erroneous conclusions from just one instrument. Especially when first testing a new tuning network, I don't trust either an untuned field-strength meter or an antenna ammeter. More than once, such instruments enabled me to load up an antenna and radiate quite a nice signal...on a harmonic frequency! These days I start with a very high impedance probe I constructed for my oscilloscope, and actually watch the waveform at the antenna, after the loading coil, as I'm adjusting. Alternately, I suppose one could use a loop or whip at a modest distance to pick up a sample and bring it back to the transmitter. It's awkward to have to provide power for the 'scope, but it does let me see that I have a sine wave of the right period to be my intended carrier. Once I've confirmed that the waveform is satisfactory, then I rely more on the field strength meter. What are your thoughts on the subject? Let us know. -James Lane (KB5NHM; P.O. Box 3097, Ft. Meade, MD 20755; E-mail: Jelane@gnn.com) "finally joined the LWCA this past month and really like the publication. I've always been interested in aero/marine beacon chasing, but now as I get upgrades in my amateur license I am becoming more interested in transmitting." "I have obtained hardcopy rules of beacon operation in the 160-190 kHz range from the Code of Federal Regulations. I have the space, equipment and skill to build a LowFER beacon....the only thing I don't have are plans! That's where I have to ask you a favor: Do you or anyone/anywhere you know have schematics for building a beacon? I am very interested in this frequency band and am in a fairly decent location for a beacon." I sent Jim the address for Ken Cornell's Scrap Book, and for Curry Communication and LF Engineering. If you have beacon information or ideas you'd like to share with him also, feel free. Sounds like he'll be able to make good use of it. -George Reaves (W, KB4WL; e-mail: george@magicnet.net) advises that W is off for the rest of the season. Power interruptions messed up his keyer and power supply, so he will resume next fall. He's glad the beacon uses tubes! George reports the antenna loading coil is wound on a 5-gallon plastic bucket, and the tank coil form is a 3-quart plastic food container. "Works best of anything I have tried. (Thanks to Jim Hagan.)" The antenna itself is a 40-foot push-up mast with two channel 2 TV antennas for a top hat. He says the ground system is marginal, but it works out OK. There's not much other LF activity around Winter Garden, which is just west of Orlando. George says that, nearing 83, "I am getting too dang old to worry and fret with this mess, but don't seem to want to give it up. Wonder if it affects others the same way?" For my part, I sure hope I'll be playing with LF antennas at 82! -Marc Cimon (AI7F; e-mail: 74034.1515@compuserve.com) noticed that Fair Radio Sales Co. (Lima, OH) is offering a Rycom VLF Receiver/Demodulator, model R-1655/URR, covering from 1 to 150 KHz, for $225. He's interested in knowing something of the reputation of this receiver, and is curious if it would suit his needs. "I am particularly interested in receiving signals in the 15-35 KHz range to relate them with solar activity," he adds. -David Jones (NR, Columbus, GA) has had NR off the air during some of our persistent West Georgia thunderstorms. He has been listening, when weather permits, at the abandoned power line on his brother's farm. On Sunday, Feb. 25, catches included Morrocco, RED, JDH, NR. Absent were ZIA and Y. Another broadcaster was booming in on March 16. This time it was France-Inter on 162 kHz about sundown. "It was so strong I had to turn off the receiver rf amp. Receiver is a Sierra Instruments." Also heard were RED and YD. David asks, "Do you know of software for RF transformers?" -Maarten VanDamme (e-mail: mvdamme@xs4all.nl) sends greetings to all from Holland. "Your information is that interesting that I even made a phone call from The Netherlands!" he said, in a message on the Longwave BBS. Glad to have you with us, Maarten. -Sam Eastey (SAM, IMG, W0IMG; 3501 Noble Ave. N., Crystal, MN) was in Florida in January when freezing rain broke off the top of the SAM antenna and brought the IMG antenna to the ground. (Hmm. Stay in Minnesota with freezing rain, or go to Florida in January and miss all the excitement. Tough choice. If Sam moved to Georgia, he could have a little of each kind of weather in January, and not have to make this difficult decision each winter.) Nice weather will be a prerequisite to getting them back on the air. Material for a top hat has been purchased, and spring time will see the antenna being lowered, the new top hat installed, and SAM being returned to the air. Portable SL is also without an antenna at the moment, he adds. Living in an urban area with plenty of noise makes LowFER activity almost impossible, but Sam does copy some beacons from the north with varying degrees of success, specifically LEK, BK, and ART. He is looking to purchase a Sony ICF-2001 receiver for use away from home. If you have one you'd like to sell, contact Sam directly. -Dave Sampson (N2ZWX, 117 Briarcliffe Rd, Dewitt NY 13214; 315/446- 1258 after 5 PM Eastern) is thinning out his receiver collection and has these for sale: Watkins-Johnson DMS-105A, 1 kHz-1600 kHz; RAK-8 with power supply and manual, 15-600 kHz; and a Rohde & Schwarz tunable amplifier, 17 Hz-650 kHz. Prices are negotiable on each of them. -Roger Thompson (AD5T; 8105 Bottlebrush Dr, Austin TX 78750; phone: 512/502-8771; fax: 502-8619; e-mail rthomps@sbctri.sbc.com) talked with Carl Lundgren (TH) during a recent trip to Washington DC. That visit, and recent reception of beacon OK, renewed his interest in LF. The reception of OK came on a HP 310A using a transformer matched 150' wire antenna and a 250 kHz low-pass filter. Other equipment includes HF transceivers preceded by converters and followed with audio DSP, but so far no other LF beacons have turned up. On MF, he has heard D and STLMO several times. Roger moved to Austin last year from St. Louis, and misses the regular reception of BA and AL, "and the association with persons in the local area with similar interests." He echoes a frequent request for a contact list for experimenters, including non-hams. "One outcome of such local interest groups could be more beacons as knowledge, equipment, funds and locations are pooled," he notes. Footnote. Enjoy the comet and send your news! Til next month, 73. - - - CONTACT LIST/COMPUTER COMMUNICATION SURVEY This survey does triple duty: it'll help us set up a database of experimenters who'd like to be able to communicate with each other (electronically or otherwise); it'll let us determine the computer capabilities and software needs of our members; and, it'll serve as registration for the BBS if you desire. It will NOT be used to generate advertising lists. DOWNLOAD ONE OF THE FOLLOWING: * If you have a PC-compatible - SURVEY.EXE or SURVEY.ZIP * If you have a non-DOS machine and a text editor that needs carriage returns at the end of each line - SURVEY.TXT * If you have a non-DOS machine and a text editor that needs carriage returns only at the end of paragraphs - SURVEY.ASC