The LOWDOWN This Month|
In the April 2015 issue of the club publication:
- "DX Downstairs" Kevin Carey presents members' LF and VLF loggings.
- "On The Air" Experimenters operating on the 160-190kHz and lower bands... and...
- "Operator Contact List" How to reach the ops... and...
- "The LF Notebook" Conducted by John Davis. News from, for and about LWCA members.
- "News From the Old World" Alan Gale keeps us informed of LF news from the "other side of the pond." This month: news of DRM tests on 177 kHz, a link to a book on the history of the BBC Transmission Department, and a review of Michael Oexner's non-directional beacon lists for 2015.
- "Ask Mr Answer Guy" April foolishness from A. Guy...a proposed communications method based on dark energy.
- "On the Longwave Trail: Curaçao & Bonaire" by Kriss Larson. Listening results and interesting radio sites in the Caribbean.
- "Ground System Bonding at KD4PBJ" by Chris Waldrup. Hints on using Cadweld bonds in home ground systems.
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| ||Communication Landmarks: Across the Atlantic Below 9 kHz|
Third test on 1 January results in 25 character message.
Over three consecutive nights, noted British DXer Paul Nicholson in Todmorden, UK, received a series of very slow BPSK transmissions from Dexter McIntyre W4DEX in Stanfield, NC, culminating in a 25 character message in the wee hours (UTC) of New Years Day 2015. Distance from W4DEX to Todmorden is 6194 km, or 3840 miles, and ERP is estimated around 150 μW.
The first signal on December 30th was Dex's grid square, "EM95," the first intelligence ever conveyed across the Atlantic on such low frequencies by private individuals. The next day, a 12 character message ("PAUL HNY DEX") was sent and received over a six hour span commencing at 0000 UTC. Then, in Paul's own words: "The third test and best result so far was a 25 character message '8822HZ 2015 JAN 1 TA TEST' sent from 2015-01-01 00:00 using 8 second symbols. This was received with Eb/N0 = -0.1dB. In the 0.125 Hz bandwidth of a code symbol, the S/N was -13.2dB."
Frequency used was 8822 Hz. Earlier in December, tests yielded copy of Dex's steady carrier near that same frequency by DL4YHF in Bielefeld, Germany (4300 miles), by IK1QFK in Cumiana, Italy (4770 miles), using custom Linux-based spectrum analysis software written by Nicholson. He also wrote the BPSK applications. Reception has also been reported in the US using Argo displays. A selection of those reports is available at Dex's Web site.
Back on June 2 (UTC), 2014, Nicholson received transmissions from McIntyre on 8970 Hz, consisting of a continuous GPS-stabilized carrier that was shifted in frequency after some hours of integration time. Paul's detailed reception report of that earlier feat, along with details and pictures of the transmitting setup, can be found at the W4DEX Web site.
Previous experiments in the sub-9kHz region have mainly been conducted in Europe, such as the kite-based transmissions of Stefan Schaefer DK7FC. His page contains a good introduction to what has been done so far, and links to additional resources. Although frequencies below 8.3 kHz, or 9 kHz in the US*, are not formally allocated in most countries, some administrations do require their citizens to obtain special permission to operate there. (*Following the last WRC, an increasing number of countries now have an explicit allocation down to 8.3 kHz for meteorological aids such as lightning detection networks.)
| ||Longwave Broadcast Outlook in 2015|
Reprieve for RTÉ; Deutschlandradio closes; and an online hoax.
There are fewer stations in the longwave broadcast band in the New Year, but the number did not drop as much as earlier expected. Responding to public pressure, RTÉ has postponed closure of its Radio 1 service on 252 kHz until 2017. Shortly after the former Atlantic 252 celebrated its 25th anniversary in September 2014, it was announced that the station would close in October. That was posponed to January. Then, Mike Terry recently forwarded word from RTÉ News that more time would be allowed for listeners in the UK to adopt other means for receiving RTÉ programs.
The closure of two of Germany's LW outlets took place at the end of 2014 as scheduled. The mediumwave stations are slated for closure in another year or so. It has further been reported that Bulgaria has ended its transmissions on 261 kHz as of year's end.
Meanwhile, a report that Polish Radio was planning to close its longwave station turned out to be false. The rumor began circulating just 3 months after the station celebrated its 15th anniversary last autumn. Mike Terry passed along word to our Message Board once it was discovered that information was false, clarifying that PR1 LW accounted for 40% of Polish Radio's listeners, and it is cheaper to operate than the FM network, the transmitter plants for which are leased from a private sector company.
LW Resources & Additional Topics
| ||Related Longwave Sites|
William Hepburn's DX Information Centre has probably the best online list of aero and marine beacons based on official license information, plus lists of LW broadcasters and time signals, and numerous resources for other types of DXing as well.
The searchable RNA database of LF beacons...not compiled from official sources, but a digest of signal reports from experienced listeners in North and Central America. It's a great tool for identifying those unknown signals. It won't always be up-to-date regarding decommissioned beacons, of course. This might somewhat limit its usefulness in targeting specific beacons to listen for, but it's still helpful if you pay attention to the most recent reported date for a given beacon.
Radio Waves Below 22 kHz Renato Romero's eclectic collection of topics pertaining to both manmade and natural radio signals from near DC to the upper end of audibility. Includes the VLF Open Lab, and articles by many contributors...some fairly orthodox, and some not. Visit: www.vlf.it
| ||QRSS and WOLF Software
Rik Strobbe's QRSS software (for transmitting extremely slow CW) is usually available from our file library, but while it is temporarily out of service, you can obtain QRSS and Rik's other useful software at the ON7YD download page.
Continuing Development of Argo. Alberto di Bene posts the latest version of Argo, a receiving tool for displaying slow CW, that performs FFT spectral analysis and displays it in ways optimized for QRSS. Many of the transoceanic LF amateur records were set using Argo at the receiving end. Argo has somewhat similar performance to Spectran, but interacts better with the user's soundcard and is customized for QRSS modes.
WOLF. Stewart Nelson devised this unique mode, a variant of BPSK. See his announcement of the MS-DOS version for more details. Now, a GUI-based version by Wolf Büscher continues to increase the mode's popularity. Find the new software at the DL4YHF site.
Spectrum Lab, at that same link, is another of Wolf's creations. In conjunction with your computer's sound card, not only is it an especially advanced spectrum analyzer, but it's also a filtering and sound processing tool, and can serve as the demodulator part of a software defined receiver.
Slow CW for Linux. Claudio Girardi (IN3OTD) has released Slow CW software for users of the Linux operating system, currently v 0.42. The program (called glfer) contains both transmit and receive capability, the latter including an FFT-based spectrum analyzer somewhat similar to those found in popular Windows Slow CW programs.
As with much open-source software in the X-world, you have to compile the C source code yourself. Users will also need additional code libraries. Links to those, plus downloadable source code, can be found at Claudio's glfer page.
Visits since last reset, 1 Jan 2014:
(Sorry, the site that managed our unique-hits counter shut down at the end of 2014 without notice to us.)