Given the social isolation imposed by the Covid-19 virus I’ve resumed interest the pursuit of DX. In ham radio jargon DX means distance. In casual conversation hams might ask one another “How’s DX”? Translated for non-hams this means “How’s propagation? Is distant radio communication optimal? A major interest for many hams is the ability to speak to others in far off exotic locations wirelessly. During the 1970’s the sun spot cycle peaked and optimally effected the ionosphere. Radio signals reflected off the upper atmosphere so efficiently that with 100 watts of power or less it was possible to talk with other hams all over the globe. While living in New York I could routinely contact the ham shack at McMurdo station on Antarctica, call sign KC4USV. [1] Both our signals were typically + 20 db over S9, enormously strong considering we were over 9,000 miles distant. We might not think of the frigid south pole as Shangi-La but it qualified as exotic DX, a distant location inaccessible to most excepting our military, well funded explorers and ham radio operators on the air.
As DX communication is challenging during the current solar minimum, innovative hams are constantly testing the ionosphere in search of band openings. Optimal DX propagation can occur suddenly during unpredictable solar flare activity. To test conditions hams will often broadcast a CQ, an invitation/call to others listening to engage in conversation. Hams calling CQ DX are searching for radio contact with distant stations in other countries. Occasionally hams will organize a DXpedition; a group of hams will travel to an exotic location, set up a radio station and become a highly sought contact pursuit by other operators seeking a “Worked All Countries Award”.
Testing DX conditions can be challenging. It’s difficult to evaluate the ionosphere when no signals are present. In this regard, DX beacons are helpful. There are many automated radio stations covering our globe which transmit beacon signals. As “radio light houses” their signals can be heard distantly when atmospheric conditions are optimal. DX conditions can also be determined by monitoring scheduled networks. Hams maintain daily “nets” over a wide rage of frequencies. Net control operators for these nets are volunteer hams operating in shifts. Two popular HF (High Frequency) nets can be heard on 14.300 MHz. During morning hours the Intercon Net is active. The Intercontinental Amateur Traffic Net [2] acts as a check in center for hams monitoring the frequency. Hams can obtain signal reports, weather condition updates and check in to rendezvous with distant friends. At 12:00 PM the Intercon Net closes and the Maritime Net resumes its net activity on 14.300 MHz. Known formally as the Maritime Mobile Service Network, [3] this volunteer group is a valuable resource to licensed hams on sea bound traffic ranging from pleasure craft to large commercial shipping, cruise ships and sometimes military vessels. Similarly, the Maritime Mobile Service Network broadcasts weather conditions to ships at sea and sometimes relays messaging to land based systems. In addition to VHF/UHF I also have an HF radio in my car. While mobile I listen to the nets on 14.300 for propagation conditions and obtain signal reports. Once you’ve checked in you’re logged into their computer system for future reference. It’s often surprising to be greeted by name upon your call sign check in. Both of these nets are very popular and supported by a huge following of the ham radio community.
When mobile, seaborne or in the air (airplanes), hams frequently exchange grid square information. In addition to simple location plotting, grid map information can assist with aiming directional beam antennas and navigation. The ARRL explains the origins of the Maidenhead Locator System. [4] HA8TKS provides an excellent Maidenhead grid location utility on a zoomable map. [5] Such resources and utilities simplify global communication coordination for mobile operators and systems.
Did I mention that ham radio and DX are great fun?
Have a great weekend!
Best regards,
Thomas D. Jay
W4TDJ Member ARRL
Thomas.Dale.Jay@gmail.com
TDJ Technology Group.com
Thomas D. Jay YouTube Channel
Corporate, private entities or publications referenced or linked in this article are the respective owners of their logos, trademarks, service marks, media content and intellectual property. Unless otherwise disclosed, Thomas D. Jay has no financial interest in companies referenced in blog articles or other published media communications. Thomas D. Jay is not a registered financial advisor. No representation is made to either buy or sell securities. Opinions expressed by Thomas D. Jay are his own. Thomas D. Jay does not employ or otherwise utilize/authorize third party agents to express his opinions, represent his interests or conduct business on his behalf except where formally contractually designated. Thomas D. Jay opts out of requests to share personal information or unidentifiable user data. Thomas D. Jay does not agree to indemnify or hold harmless vendors, clients or third parties to related contractual agreements and reserves the right to applicable legal remedies in lieu of arbitration. Thomas D. Jay retains all copyright and moral rights to his published material, content and brand marketing, and shall in no case be represented, depicted or characterized by parties/entities other than his published "About Thomas D. Jay" descriptor. Contractual agreements are to be written and interpreted in the English language and are subject to the laws of the United States. These terms and conditions shall supersede any conflicting agreement. Clients, vendors and concerned parties should check my blog site at www.thomasdalejay.blogspot.com for periodic updates or changes to theses terms.
References and acknowledgements:
[1] McMurdo station on Antarctica, call sign KC4USV
[2] Intercontinental Amateur Traffic Net
[3] Maritime Mobile Service Network
[4] The ARRL explains the origins of the Maidenhead Locator System
[5] Maidenhead grid location utility HA8TKS
I originally posted this article on my technology web site TDJ Technology Group.com. As it relates to amateur radio I've decided to post it on my ham radio blog as well. Please keep in mind I was writing for non-ham technologists. Here goes:
After weeks of news media frenzy on the Covid-19 epidemic we’re all weary of the social isolation imposed on friends and families. Many stay connected via television, and social media but another social network remains unseen to most. Amateur radio operators (known colloquially as ham operators) populate their FCC licensed radio spectrum sandwiched between commercial radio and TV channels. There are over 764,000 federally licensed hams in the US, with several million internationally. In spite of Covid-19, the global ham radio community remains actively social, communicating long distance wirelessly.
By day I’m an investor, writer and technology consultant. After hours the large computer screen on my desk becomes an SDR display for my amateur radio station (SDR is Software Defined Radio). Last night I tuned in to monitor several ham radio contest events. The month of April features many Spring season “QSO parties”. A QSO party is a contest in which hams make radio contact with as many other stations as possible in a predetermined time period (usually a day or two). WA7BNM (Bruce Horn) publishes a comprehensive list of ham radio contest schedules with eight events scheduled this April. [1] Thanks Bruce for a great resource.
As a hobby, amateur radio has evolved to a new level of sophistication. SDR is Software Defined Radio. Recent adaption of FPGAs (Field Programmable Gate Arrays, a specialized ASIC device technology, (Application Specific Integrated Circuits) found in communications electronics now provide a graphic view of the RF spectrum and its radio signal inhabitants. Utilizing “direct RF (Radio Frequency) sampling” techniques, ASIC technology extracts a radio’s received spectral data and displays it on a computer screen much as an integer number line, or in this case a spectral line extending above and below the zero point frequency (with zero referencing the radio’s tuning dial pointer). SDR graphic displays have revealed that as ham radio operators, we also comprise a real life “Matrix”. Hams populating their FCC allocated radio spectrum can be seen as individual signal traces along the spectral line. The signal traces scroll over time on a “water fall” display leaving after image “foot prints” behind. Run the embedded YouTube video I’ve prepared and you can see the spectral display I’ve described (approx 2 minutes run time). [2] The signals you can hear are captured by the tuner centered on the spectral display. Switching display modes can also provide an oscilloscope view of the signal’s audio envelope. In the past, radio receiver display technology was little more than a box with an inscribed tuning dial. SDR technology was first seen in military applications but now enabling ASIC device technology is also utilized in many automotive and consumer products. The display images in my video were taken from my Icom IC-7610 transceiver. Icom’s first SDR radio the IC-7300 features an Altera EP4CE55F23I7N Cyclone IV E running at 200MHz) which facilitates simultaneous audio processing and graphic display of this information. Advanced specifications aside, SDR has helped enhance the “social” aspect of our hobby. At a glance hams can “see” live radio spectrum to quickly identify lone signals or clustered contest/network activity. Tuning the radio is simplified. Point at a signal trace on the graphic display and a mouse click will tune there instantly, minimal dial tweaking necessary.
Ham radio contest enthusiasts empowered by SDR have infused the community with new interest. Many of these social contest events feature highly coveted award certificates. A few examples are: The DX Century Club award, (DX meaning distance) is presented to operators confirming contact with one hundred international stations. Similarly there’s a Worked All Countries award, Worked All States award and Worked All Counties Award (challenging as you must confirm radio contact with hams populating every state county in the US).
In spite of the Covid-19 epidemic amateur radio remains a vibrant, socially active hobby connecting hams globally. In times of emergency, natural disasters, or communications outages, hams provide a volunteer base of highly skilled communications operators with global reach. Although there’s been no call for ham radio communications during the current Covid-19 epidemic, a valuable volunteer resource stands ready. In the interim, social distancing at light speed is great fun. Dropping out of warp now. See you on the web.
For additional background on SDR technology see my March 2017 article “New Trends in The Field Programmable Gate Array Market - Software Defined Radio”. [3]
For additional information on Amateur Radio see the American Radio Relay League web site. [4]
Stay safe out there.
Regards to all,
Thomas D. Jay
W4TDJ Member ARRL
Thomas.Dale.Jay@gmail.com
TDJ Technology Group.com
Thomas D. Jay YouTube Channel
Corporate, private entities or publications referenced or linked in this article are the respective owners of their logos, trademarks, service marks, media content and intellectual property. Unless otherwise disclosed, Thomas D. Jay has no financial interest in companies referenced in blog articles or other published media communications. Thomas D. Jay is not a registered financial advisor. No representation is made to either buy or sell securities. Opinions expressed by Thomas D. Jay are his own. Thomas D. Jay does not employ or otherwise utilize/authorize third party agents to express his opinions, represent his interests or conduct business on his behalf except where formally contractually designated. Thomas D. Jay opts out of requests to share personal information or unidentifiable user data. Thomas D. Jay does not agree to indemnify or hold harmless vendors, clients or third parties to related contractual agreements and reserves the right to applicable legal remedies in lieu of arbitration. Thomas D. Jay retains all copyright and moral rights to his published material, content and brand marketing, and shall in no case be represented, depicted or characterized by parties/entities other than his published "About Thomas D. Jay" descriptor. Contractual agreements are to be written and interpreted in the English language and are subject to the laws of the United States. These terms and conditions shall supersede any conflicting agreement. Clients, vendors and concerned parties should check my blog site at www.thomasdalejay.blogspot.com for periodic updates or changes to theses terms.
References and acknowledgements:
[1] WA7BNM, Bruce Horn web site.
https://www.contestcalendar.com/index.html
[2] Thomas D. Jay, YouTube Channel Video
https://youtu.be/fMkHVz23lkw
[3] Thomas D. Jay, Blog article, New Trends in Field Programmable Gate Arrays
https://thomasdalejay.blogspot.com/2017/03/new-trends-in-field-programmable-gate.html
[4] American Radio Relay League web site
arrl.org
