NOTEBK22.TXT THE NOTEBOOK (From THE LOWDOWN, January 1995) 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 (All Rights Reserved; not for distribution on commercial services!) Happy New Year, and what a month! Propagation improved dramatically in December, but from every part of the country come reports that QRN remains high. I don't know if the Weather Service has officially declared this an El Nino year, but the Pacific is warm and the southern branch of the jet stream keeps supplying weather systems with fuel for electrical activity. Still, as you have seen in the LF and MF On the Air sections (and probably also in the NDB loggings), considerable DX is possible. There were more QSOs in the past month or so than were reported all last year, apparently. Although I got a later start on the database roundup this year than last, I was able to work on these columns every evening from Thanksgiving to nearly Christmas. That avoided some of the usual time crunch at deadline. However, the size of the 1750 Meter and Top End sections causes something of a space crunch. If we don't get to a few letters this time, don't worry; they'll give us a head start for next month, when the beacon listings won't be so large. Meantime, we'd like to hear your news as well, so send it in. *More Cosmic Connection This is still not the comprehensive, once-and-for-all summary of the topic I'd hoped to write this time, but there are a few more bits and pieces that may interest you until we get back to the subject again. It might also be a good time to mention the reason for calling this topic "Lightning--The Cosmic Connection," as we did in the first piece, some months ago. It's because the confirmation of upward lightning ties earthly weather phenomena to the ionosphere, which in turn is influenced by the sun. Now there are suggestions these upward paths may be conduits for cloud-to-ground lightning sferics into the magnetosphere, where whistlers are produced. The January, 1995, Astronomy magazine has a news item on page 24 about the gamma-ray bursts from Earth's own upper atmosphere, which are now thought to be related in some way to intense thunderstorm activity--possibly even the fascinating upward discharges. There's a photo by Walter Lyons from the July, 1993, work of Mission Research Corporation, showing a discharge structure 40 to 50 km above the ground. There is a certain resemblance to aurora, which also takes place in that general altitude range. (This may also relate to sporadic-E propagation.) At this point, there is no definite link between upward discharges and gamma-ray bursts, only a connection between the bursts and strong electrical storms. The energy levels of the gamma rays are said to be very high, greater than many of cosmic origin. (I wonder if there's a possibility the gamma rays result from a yet unidentified cause, in which case the electrical discharge may be triggered by ionization from the radiation, rather than the other way around.) Member Mark Langenfeld called my attention to the Astronomy article, observing that the "cosmic connection" gets more cosmic all the time. He has found several other intriguing articles, too: "You really must see the May 27, 1994 issue of SCIENCE (Vol. 264), which has two related pieces. The first, at pp. 1250-1251, deals with 'high-altitude flashes'; the second, at pp. 1313- 1316, discusses atmospheric gamma ray bursts (and makes a cautious causal connection to the flashes). The August 1, 1994, issue of AVIATION WEEK & SPACE TECHNOLOGY also has a nice one-page article on the subject." The suggestion linking upward ionization to magnetospheric coupling is found in Franz, et al., SCIENCE, Vol. 249, 6 July 1990, pp. 48-51. *Periodical Shelf Plus The designation "plus" this time is because a fair amount of the reading matter is not just from magazines, but also from catalogs and on-line sources. >> Steve McGreevy authored an excellent introduction to sferics and whistlers for the January, 1995, Popular Communications. Check it out. In addition to discussing whistlers, the article describes a number of other natural radio phenomena as well. >> Want some background on propagation, auroras, sunspot measurement termino- logy, the effects of the sun on weather, and other related phenomena? The Solar Terrestrial Dispatch has a series of files we mentioned a few months back, available by Internet FTP, that collectively make up an excellent document called "Understanding Solar Terrestrial Reports." This is now avail- able on the Longwave BBS (Have I mentioned the Longwave BBS lately? It supports 9600 baud now, and I hear it's still free!) as SOLTERR.ZIP, and as separate text files as well. The section on LF propagation is rather small; apparently they don't consider it as interesting as HF propagation. Still, the document is worthwhile for anyone who wants to learn some fundamentals of propagation forecasting, or who is curious about Earth's astrophysical relationship with our home star. >> The Ramsey Electronics winter catalog (739 Canning Parkway, Victor, NY 14564; 716-924-4560) features several new products, some of which are applic- able to LowFERs, MedFERs, and hams. The CW-700 Micro Memory Keyer stores four messages, or up to 32 with an optional memory add-on. It's not exactly cheap at $69.95 for the kit, $14.95 for the case, and $29.95 for the memory option, but it's a quick, convenient way to go. If you've been thinking about a narrowband audio filter, but don't have the budget for a fancy DSP unit yet, the AF-1 Hi-Q CW Audio Filter kit might be useful. It features four selectable bandwidths from 100 - 750 Hz, and an adjustable center frequency. It's $34.95 for the kit (the case is another $14.95), or $69.95 wired. The SG-215 RF Signal Generator uses direct digital synthesis (DDS) to produce outputs from 40 kHz to 15 MHz in 10 Hz steps, making it potentially useful as an agile frequency source for LowFERs and MedFERs. While the Novatech DDS-1kit (for LF) and DDS-3 (LF or MF) are a lot less than the $229.95 SG-215 kit price, the Ramsey offering has the advantage of including a freq- uency display, memories, a keypad for frequency entry, and a spin knob for VFO-like operation. *The Mailbag >> Arliss N. Thompson (W7XU, RR 1 Box 117A, Parker, SD 57053) has been an LF enthusiast for some time, but hadn't heard a LowFER until December 14. He unrolled a quarter mile of electric fence wire across an open field, atop a layer of snow, and connected it directly to his Kenwood TS-850. The venture netted three beacons that very night: LEK with its regular ID; KRY, with ID and QSL address; and BK, with the message "de BK BK BK wind is calm BT." Arliss remarks, "It was exciting to actually hear signals! I'll have to make a matching unit and get the wire off the snow and see what else I can hear." His QTH is near the center of locator grid EN13, in southeastern South Dakota. >> Walt Glazar (WI, W3WI, Pickens, SC) advises that WI is only on during hours of darkness this year, instead of 24 hours a day, due to negligible reports from the previous full-time operation. He continues in Coherent CW mode on 188.700, and will once again be by request during the spring and summer months. >> Max Carter (MAX, Wheatland, WY) has shifted MAX up 500 Hz to 175.750 to get a little farther away from GWEN. "On a recent trip across Nebraska, I was able to copy MAX at 1 baud BPSK out to about 250 miles, but beyond that, copy was only good between GWEN transmissions. GWEN seems to fill every nook and cranny of the 160 - 175 kHz portion with RF energy. My receiver is quite tolerant of impulse-type noise, but the near-Gaussian nature of GWEN emissions is more than it can put up with when the desired signal is weak." >> Lyle Koehler (LEK, MIN, K0LR; Revised address: Rt 1 Box 659, Aitkin, MN 56431) was unable to copy the MAX BPSK transmission a few days last month, but found out later that the transmitter was down for adjustments briefly, and was operating at 1 baud BPSK for a while. Using Bill de Carle's COHERENT software, Lyle normally has consistent copy of Max's 10 baud BPSK. To get an idea how effective that program is, check the printout of Lyle's computer screen, at the top of the next page. (GRAPHIC NOT AVAILABLE IN THIS FILE) That's one character per second, over a distance of 600+ miles, with static, GWEN side- bands, and all! Shortly into the next-to-last line of copy, Lyle turned on the frame grabber function, reducing the effects of interference, although a strong GWEN burst results in some error on the final line. Lyle comments on the continuing QRN: "Mother Nature still isn't being fair to LowFERs. December 11 at 0630 local time it was -12 degrees F at my location, and the static crashes were so bad I couldn't even copy BK's 5 dB over S9 signal." During quieter days, however, he logged 17 LowFERs in a month (see the 1750 Meter Band section for details). "The LowFER season is off to a pretty good start, and if the QRN ever gives us a break you're going to have a long list of reception reports." December 1 was the best opening so far for Lyle, both in early morning and again in the evening. Also, he says, "there has been a pipeline between here and XJ's location. XJ and LEK had QSOs on 11/22, 11/28 and 12/1. At 2300 CST on 12/1, XJ's signal was 599 over the 700+ mile path!" Lyle reports: "I have been playing with simple frequency synthesizer concepts that might provide LowFERs with frequency agility. So far even the simplest one requires several ICs. My pet approach uses the sound output from a PC as a programmable reference generator, and controls a divider in the PLL circuit via an LPT port. It can be used in combination with my PC beacon identifier/message generator program. If I get something working well I'll try to write it up." "Because of the lack of stations with BPSK receive capability I have discontinued the all-night BPSK transmission schedule for LEK. I will send BPSK at any time upon request, and will resume scheduled transmissions if interest picks up." >> Bill Lake (SB, WB6RIJ, Santa Barbara, CA) has a LowFER operating on 184.3 kHz on weekend mornings now, and hopes to have a permanent station soon. Bill is another satisfied user of the COHERENT software, communicating each weekend with Dave Curry, PLI, via Coherent CW. "The CCW really makes a difference in being able to hear the weak beacons," he reports. His rig is a Curry Communi- cations Signature Series with an audio Q-multiplier. He feeds a 40-foot vertical with mid-loading. >> Dave Curry (PLI, Burbank, CA) notes that he and SB are over 100 miles apart, and says the COHERENT software makes the distance "a piece of cake. I hope more LowFERs will consider this when thinking about low power DX." He says "Bill (SB) has a lot of energy and enthusiasm with 1750 and is also interested in the MedFER band as well." Dave also talks regularly with ELU, who makes use of SSB. Both stations use transverters with their amateur transceivers, allowing them "to use all the 'bells and whistles'" of the transceivers, including different modes such as RTTY and AMTOR. >> Doug Williams (OER, Watauga, TN) reports a slight frequency change, reflected in this month's lists. He also changed transmitters. "The new transmitter was built from the kit sold by 624 Kits. It is based on a design that was published in the May, '94, issue of The Lowdown. The kit is of good quality and went together with no problems. I wound my tank coil with some 22 Ga. magnet wire that I happened to have, but I plan to wind a new coil as soon as I receive the litz wire that was ordered the other day." Last winter this column carried a fair amount of discussion on the Timewave DSP-9 and DSP-59 digital audio filters. While nearly all the comments were favorable, one frequently expressed desire was for an even narrower CW filter. It appears they have responded to that need in the DSP-59+, which Doug recently acquired: "My new Timewave DSP-59+ audio filter has turned out to be a big help in pulling beacons out of the mud. Its narrowest setting is 25Hz and is extremely sharp. I was able to hear TUK for the first time this year using this filter. Without the filter, TUK is buried in the noise even with my narrowest (250Hz) I.F. filters in-line." More than that, it helped him hear WI, his first LowFER logging of the season! >> Bill Cantrell (TEXAS, WD5CVG, Haslet, TX) reports that TEXAS has been on the air continuously for seven years now. "I lost the top hat in a stiff wind storm a couple of years ago and have yet to replace it. Despite this limitation, Bill Bowers and Rick Wright in Oklahoma can still receive the beacon--although just barely. (By the way, the actual carrier frequency is 184.51425 kHz.)" Bill says the telescoping mast was due to be replaced by a Rohn 25 tower with a custom welded top hat, but a boating accident resulted in a broken leg this fall, so the upgrade has been postponed until possibly springtime. >> Carl Lundgren Jr. (TH, W2AZQ, Colts Neck, NJ) added holiday wishes to his update, which included word that TH now sends QSL info during daylight hours, and "TH" at night. Operation is CW, 24 hours a day, on 189.36 kHz. Carl mentions there's a chance he may be retiring to South Carolina in a few years. Another LowFER would always be welcome in the Southeast "neighborhood." > Bill Bowers (Rt 3 Box 177AC, Chandler, OK 74843) has identified another source of RFI that he did not expect: "When my trusty 20 year old soldering iron died, I decided to splurge and get a temperature controlled soldering station. I picked a unit from Ocean States Electronics (Part No. SL-90). This iron had not only temperature control but also digital readout of the tip temperature. It sure seemed like the ultimate soldering iron- big mistake!! I was about to throw one of Ken Cornell's active whip circuits in the trash when I finally figured out that the problem was my beautiful new soldering station. That unit radiates more low frequency RF than a dozen fluorescent lights." It may be that a lot of temperature controlled solder stations would give this same problem, so if your circumstances require soldering anywhere near your receiving antenna, it might be wiser to consider a conventional iron or pencil. Bill says he passed along word "so someone else would not make the $99 mistake I did." >> Dave Sampson (Dewitt, NY) has a WWII vintage Navy VLF receiver, type RAK-7, for sale. He says it is in working condition, with power supply and manual, and is asking $100. "Pick up only, or will deliver within reasonable distance," he adds. Call him at 315-446-1258 after 7:30 pm. >> Donald E. Moth (MPK, Chittenango, NY) should have his MF beacon on by now, and a LowFER soon. The MedFER is a modified Ramsey AM-1 kit with crystal control and a CD4024 divide-by-four circuit to set the frequency. It's at the base of a 10 foot vertical with tophat. The LF version on 183.5 kHz is built and tested. The antenna is under construction. >> Brice Anderson (BA, IE) and Lyle Koehler (LEK, MIN) have been conducting gray-line propagation tests on MF. The enhancement along the sunset terminator does manifest itself pretty well for MedFERs, apparently. With sunset about 4:30 pm at Lancaster, IL, Brice tends to hear SEA for a while, with MIN appearing shortly after. About that time VA and SC also come through. Brice says the path between IE and MIN gets better, peaking about 5:15 pm Central. At last word, they hadn't managed a QSO on MF, though, with QSB rapid and deep. >> Mitchell Lee (MEL, San Jose, CA) reports some antenna changes there. The previous 30 foot vertical plus 20 foot L-wire, loaded at the apex, proved too unwieldy atop the roof. The rotomite stepper relay also had a tendency to rectify AM broadcast signals, and loading depended heavily on the weather. The present antenna consists of two 10 foot TV masts brazed together, with a new stepper relay (11 or 12 positions, 6 contact sets) at the apex, switching various inductors, and/or the L-section, in as needed. The whole thing is operated from indoors via a twisted pair, permitting ham band use as well. A 97 µH coil is used with the MEL antenna, and provides center loading for 160 meter local work. For LF receiving, however, a bank of 5 mH coils can be switched to give a total inductance from 5 to 20 mH. They're not very high-Q, so the technique tunes the antenna broadly in about 50 kHz steps. At 80 m, the vertical and L together are l/4, and a 7 µH inductor brings the feed point to 50 ohms or more. At 40, 30, and 20 meters, the vertical alone is l/2, and 2/3 wavelength, in turn. No inductors are needed on the latter three bands. Mitchell had comments on the use of LORAN for frequency and timing, which I'll need a while to digest. We'll try to have more on that topic next month. *LATE NEWS BULLETINS: LWCA TO PARTICIPATE IN HCJB'S "DX PARTYLINE"? Just before deadline for this issue, I was contacted by Richard McVicar, producer of "DX Partyline" on shortwave broadcaster HCJB in Quito, Ecuador. He asked if the LWCA would like to have a 5-minute audio segment each month on the program. He says: "While our main focus is on shortwave broadcast station DXing, we like to include information to generate interest in DXing on other frequencies as well. On each program, we usually have one or two 5-minute spots from various DX clubs. Someone in the club sends a monthly report on club activities with perhaps some aspect of the radio hobby looked-at in detail.... I think many listeners to the DX Partyline would enjoy learning more about longwave DXing and experimenting. Such a feature might help generate some new memberships in the LWCA as well." Personally, I believe this would be a great apportunity for us. By the time you read this, I will have contacted our other editors to see if they'd like to contribute features on their specialties, and I imagine many of our readers would be able to report on their activities in a way that would interest listeners. I could help organize such an audio segment if desired, and I gather we have other members with announcing and production backgrounds too. So what do you think? Is this a project we should undertake? Please let me know at this column as soon as possible. Thanks! CALL FOR ARTICLES Last winter, I mentioned the idea of a series of introductory articles on Digital Signal Processing, since most available books and periodicals assume a depth of background many of us don't have. I've outlined a few early articles (a review of filter concepts and terminology, how the time domain relates to frequency domain, the basics of FIR digital filters, etc.). However, to take the subject onward from there, we'll need some practical articles about DSP algorithms and real-world hardware. If you have hands-on experience with Motorola, Texas Instruments, Analog Devices, or other DSP circuits we mere mortals might be able to get, and would be willing to write about them, please let me know at the address for this column. I envision starting the series in the late spring, when material for The LOWDOWN starts to dwindle, and carry it through the summer. If we could coordinate a basic but thorough series of introductory articles, it might be of significant benefit to our members. Thanks! --John * Lots more ahead in February. 73. . . .