(From The LOWDOWN, July, 1997) "The LF Notebook" The Mailbag, News and Comments About LF Radio, Etc. John H. Davis, Box 367, Warm Springs, GA 31830 - E-mail - longwave@mindspring.com - Web - http://members.aol.com/lwcanews/ Snap, Crackle, Ka-BOOM! Rice Krispies will not be my favorite cereal for a while...at least, not unless I'm wearing ear plugs. In fact, I may swear off breakfast entirely. Several times during column preparation week, Mother Nature tried to make toast of your columnist and his staff at the TV station! Fortunately, we escaped too much damage, other than our nerves, but were off the air for extended power outages. E-mail Advisory. Even the new Mindspring e-mail has been less than totally reliable this month. Therefore, I am instituting a new policy of acknowledging receipt of all e-mail intended for this column. If you don't hear back from me in 48 hours of sending e-mail, you should assume I didn't receive it and try again. As Mr. Answer Guy says, "Computing is going to be wonderful. If they can ever make it work." You'll notice a very small Mailbag section this month. That's because most of the correspondence dealt with last month's feature topics, so I've included it in those discussions instead. Keep those cards, letters, and e-mail coming, so we'll have something for the August drought, too! Periodical Shelf: The Return of Speleonics No, it's not some new language or a cult religion. Speleonics is--or was--a more-or-less quarterly quarterly publication, put together by the Communications and Electronics Section of the National Speleological Society, most of whose members are involved in caving and related activities. After a three-year hiatus, publication has resumed with the long-awaited Issue 21 (Volume VI, Number 1). Dated March, 1997, it arrived too late in April for your columnist to mention in the May Notebook column (and inadvertently got zapped from the June column). Another issue is planned for this summer, if sufficient material is available. The recent issue features several articles of interest to LF experimenters. Topping the list is "Historic Earth Dipole Communications" by Frank Reid. This article describes methods of injecting currents into the earth, which can be detected at a distance, such as with the Power Buzzer and the Fullerphone, both of World War I fame. The British Fullerphone was unique in being able to send voice and telegraphy simultaneously over a single-wire circuit. The design contained no amplifying devices, but was so sensitive that telegraphy could be maintained through extremely high-resistance connections, or in the presence of ground leakage. It could be used as an earth-dipole receiver, and could detect ground-return currens from conventional single- wire telegraphs, without its own signals being observable to such equipment. The French Power Buzzer used an elegantly simple "transmitter," consisting of... an electric buzzer! The buzzer also had a secondary coil, though, rather like a medium impedance version of a Model T ignition coil. The secondary was coupled into the earth with ground rods spaced about 100 yards apart. The buzzer's vibrating contact was resonant at a particular frequency, so receiving operators (who used a similar ground- rod "antenna" feeding into a vacuum tube audio amplifier) would be able to distinguish between any of several units that might be operating in the same area. (Ear-brain selectivity was necessary, since DSP was still several decades away!) Range was said to be about 2,000 yards under ordinary conditions, with antennas aligned correctly; and nearly double that under extraordinary circumstances. Frank's article contains far more fascinating details of both devices, a good bibliography, and a discussion of possible earth-dipole applications in caving. Brian Pease wrote "The D-Q Beacon Receiver," about a high performance 3496 Hz "cave radio" beacon receiver that can be used for determining location or for communication. The double quadrature detection circuitry is described in considerable detail, along with an H-field transmitter circuit. Other articles in this edition deal with NiCad battery conditioning and charging circuits, radio crosslink experiments, and light sources for cave exploration. Membership in the Communications and Electronics Section of the NSS is available to all interested parties. It costs US$6 in the US, Canada and Mexico, US$8 elsewhere, and extends for four issues of the newsletter (however long that interval may be chronologically). If you have an amateur radio call sign or an NSS member number, include those. Send subscription requests to: Joe Giddens, N5IOZ, Treasurer, PO Box 738, Bearden AR 71720. - A related organization is the Cave Radio and Electronics Group of the British Cave Research Association. CREG also disseminates information on the use of electronics in caving, to members in the UK and worldwide. Speleonics and the CREG Journal coordinate their editorial efforts to avoid much duplication. You can view their Web page at http://www.sat.dundee.ac.uk/~arb/creg/ To receive current information on CREG subscriptions, contact one of the following, and include a self-addressed, stamped envelope or an International Reply Coupon, as appropriate: Stephen Shope, Sandia Research Associates, 3411 Candelaria NE, Albequerque NM 87107; or, Bill Purvis, 35 Chapel Road, Penketh, Warrington WA5 2NG, UK (w.purvis@dl.ac.uk). Powerhouse of the Rockies? The schedule tripling of power for WWVB in September will indeed be a significant improvement at most locations in North America. As mentioned previously, the National Institute of Standards and Technology is currently working on the increase to make reception more reliable. At least one class of consumer product already on the market will benefit from the boost, and others are expected to follow. The station took delivery of some Navy FRT 72 transmitters and constructed of a new building to house them last fall. (Anyone have any details on these transmitters?) They have since been cleaned thoroughly and installed in the new building. A vault was built for 3000 feet of Heliax transmission line to the antenna system. The plan is to incorporate the old WWVL antenna into the new configuration, so it is unlikely that we'll ever see 20 kHz used again for standard frequency transmissions from that site. Design work for the new antenna has been completed within the past quarter, but construction has yet to be finished. Also within the last quarter, a new primary power transformer was put in place, and a new air system was designed. Air system installation remains, as does wiring of the power control circuits, and installation of new components in the transmitters themselves. The Heliax transmission line also remains to be installed. The target date for 40 kw operation was originally September 19, but the most recent update on the NIST Web site now merely says "September." When it does take place, a signal better than 100 uV/m should cover all the contiguous 48 states. Unless the new antenna array is significantly directional (this has not yet been mentioned by NIST, but seems possible), we might expect the current 2500, 500, and 100 uV/m contours to become roughly 4385, 877, and 175 uV/m, respectively. (See the LW Home Page and its LF Utilities page for further details and updates.) With Loran on the way out, and GPS still rather inconvenient for low-budget time keeping applications, the WWVB signal is the best candidate for such devices as self-setting clocks, watches, computers and VCRs. The German firm which has been making self-setting time pieces for several years in Europe is now offering similar products in North America. Arcron Zeit advertises a growing product line, with a travel alarm at $70, clocks beginning at $80, to deluxe wristwatches at about $230 US. A very convenient desktop model is priced about $130, and is said to be able to work with as little as 20 uV/m of signal. The Executive PC version, shown at right, is due to be on the market now for $149.95. Its unique feature is an RS-232 port, which can be used with the supplied PC software to maintain the computer's clock to a very precise value. It would not be hard to imagine using such timing information to discipline a secondary frequency standard over a long time frame, as well as synchronizing recordings of Natural Radio phenomena. The company has Web information on their products at http://www.arctime.com/ or you can contact them at (800) 985-TIME, or at (630) 472-9999. CONSOL Revisited Last month's mention of the final CONSOL station jogged the memories of several members. Jacques d'Avignon, who originally inquired about the Stavanger station, learned just after the June column was on its way to headquarters that the station in Norway had already ceased operation, and is now a simple NDB. "So much for wanting to record the last station," he notes. However, other folks have stepped up to fill in some of the gaps in your columnist's knowledge...for which I am most grateful. Although I spent quite a lot of time listening to LF in the early and mid-Sixties, it was primarily for transcribed weather broadcasts. I didn't have the foggiest idea that CONSOL stations were operational in the U.S. and elsewhere at that time. Dr. Reinhard Klein-Arendt (Bachemer Strasse 57, 50931 Cologne, Germany; e-mail: ama05@rs1.rrz.Uni-Koeln.DE) writes, "just read the comments about the Norwegian CONSOL LEC. The CONSOL service has been decommissioned one year ago or so. Right now I can hear LEC still being on 319, but as an ordinary beacon (ID only)." As for the other stations in the same chain with LEC, he notes "Bushmills was MWN on 266 and Ploneis (spelt Plo-ne-is, which was in fact in the Bretagne, France) was FRQ on 257 kHz." "A few years ago the longwave bands were full of those CONSOLS. A very interesting chain was on 332.5 with LEX Andoya (northern Norway), LJS Bear Island and LMC Jan Mayen, which could be heard often even during the day in wintertime. These were all decommissioned in February 1985. Other stations like Rybackij in Russia were closed at the beginning of the Nineties." Reinhard also has some references which, if one has access to a good technical library with a bit of older material, may help: Picao 1946, United Kingdom Paper No.1, "Consol" ICAO: Information Concerning the Long Distance Radio Navigation Aid Consol, Circular 46-AN/41 (1955) Kramar, Ernst: Radio Navigation Aids for Medium and Long Distances with Special Regard to Consol. International Conference on Lighthouses and other Aids to Navigation. Scheveningen (Holland) 1955 U.S. Department of Commerce, Office of Technical Services: Report on Electronic System of Air Navigation. Washington 25, D.C. U.K. Ministry of Transport and Civil Aviation: Consol, a Radio Aid to Navigation, C.A.P. 59, 1955 Grasson, P & P. Hugon: "Un Appareil de Lecture Automatique des Signaux Consol", in: Navigation Revue Technique 1/1, Paris 1953 Consolan - Long Range Navigational Aid Facility, Engineering Information by Headquarters Airways and Air Communication Service, Military Air Transport Service, Andrews Air Force Base, Washington 25, D.C., January 1957 He notes that CONSOL was originally developed at the beginning of the 1940s by the German radio enterprise C. Lorenz AG on behalf of the Luftwaffe and the German Navy. The Lorenz system was developed further and widely used after the war, even though LORAN was also available by then, because of its greater range and propagation stability. Additional material on the system was generously furnished this month by Don Schimmel, although the postal service kept hold of it until this week, and I don't have time to do it justice. We will continue this topic next month, though, because the technical details are interesting in their own right. (Note: That followup has been delayed, in actuality.) DGPS Followup David Jones (Columbus, GA; d.jones160@genie.geis.com) drove to Miller's Ferry, Alabama on June 10, to get a first-hand look at the Differential GPS station there on 320kHz. He reports, "The transmitting antenna is a T sloping from the top of a microwave tower. No LowFER would be proud of the arrangement. Supposedly it will work out to 150 miles. I will give it a try soon. Miller's Ferry is near Camdem in a big bend of the Alabama River. Also there are two sets of two GPS antennas. Good backup. Nautel made the coupler, the only part with a readable label on it. I expected something more elaborate." Later, though, he says from Columbus, "I noticed that Millers Ferry comes in nicely in my car. I should not bad mouth the antenna." Walt Fowler (KC5ZDX; wfowler@jumpnet.com), followed up with this note, "The transmitter at Miller"s Ferry is a Starlink 1KW transmitter. I have not visited the site and seen the antenna. (David's) comment about the antenna may explain what I consider poor signal coverage from the site. I had previously thought it was due to poor ground conductivity, because we helped install the transmitter in Sallisaw OK at 299KHz, and we can receive it in Austin, Texas, in the daytime at about 50uv/M. Austin is 390 miles from Sallisaw." He also advises, "We have reports of the Appleton, WA 300KHz site being received in Montana. I would appreciate additional reports about how far the converted GWEN with its fantastic antenna is being received." Walt also pointed us toward some additional information on the data formats of DGPS beacons. "The data format for the MSK modulation on DGPS beacons includes messages which identify the beacon as well as the Lat-Lon of the transmitter. As I pointed out before the MSK modulation can be detected with a narrow-band discriminator similar to FM demodulation. The data format is complicated and was defined by the Radio Technical Commission (RTC). The only source of income for the RTC, which is a non-profit origination is the publishing of standards and protocols. The RTC is composed of representatives from government and industry which set down in meeting and hash out standards. I don't think they have a web page, however the information about protocols can be bought from NAVTECH for 70$. Navtech has a web page at www.navtechgps.com. You would need item1351 titled "1994 RTCM SC-104 recommended standards for differential navstar GPS service". This document would have a lot of extraneous information but the format for decoding the information is in it. The status and ID number of the DGPS beacons can be found on the US Coast Guard web pages." On To The Mailbag - Bill Cantrell (TEXAS, WD5CVG) advises, "The TEXAS Beacon will remain on the air throughout the summer, as always, but I had to roll up the chicken-wire groundplane around the tower. I can't mow the grass unless I roll it up first. Rolling up 800 feet of chicken wire (4,000 sq. ft.) is just too exhausting, especially when the grass grows through it over the septic field." "I recently made some repairs to the TEXAS Beacon Transmitter that has affected its operating frequency. I had to rebuild the crystal divider circuit and now the parasitics are a little different than they used to be. The new carrier frequency is 184.480 kHz (it used to be 184.514). Also, I conducted some signal strength experiments with Bill Bowers yesterday. Expect an article soon." "With all of the ground-plane-chicken-wire rolled up for the summer, you should expect to see a 6 dB drop in signal strength compared to whatever you have been measuring. I will roll it out again after the summer mowing season is over, or on special request." - Jim Dolson (WB8ZDB; dolsonj@ix.netcom.com) writes, "I've been a ham radio operator for twenty years and am looking for something new. I ran across Curry Communications web page by accident and found out about the 1750 meter band. Is there anyone active in Michigan that you know of that I could talk to about getting on this band? I live in western Michigan around Grand Rapids." Anyone? - Dave Riley (1A, AA1A; daveaa1a@ssih.com) forwarded some interesting comments on a "laser transverter," a way of doing something a little different with LowFER and ham gear. Look for more on this next time. Footnotes. Enjoy your summer, and let us hear from you soon. 73. - - -