2 Meter Single Sideband - Beyond the Line of Sight
So you are thinking of taking on the challenges of 2-Meter Weak Signal operation.
The time is right. We are now on the down slope of the sunspot cycle. The upper HF band DX opportunities will be far and few between soon. In the past few years, many of the major Ham equipment manufacturers have developed full coverage HF to VHF transceivers, so there is plenty out there to choose and use. Also many new and used All-Mode rigs for 2-Meters are available.
Many Hams who become Weak Signal enthusiasts, tend to back into this part of the Ham radio hobby. Many times it is by pure accident. Once you have experienced the joy of working a DX event on 2 Meter SSB, it is easy to get hooked and it becomes your primary focus for that DX’ing urge. It can relieve that HF burnout.
2-Meter SSB is not for everyone. If you are looking for results like would see on 20 Meters at the peak of the sunspot cycle, 2 Meter SSB will not produce the same results. But, if you like studying propagation, being at the right place at the right time, and enjoying unique and special events, then this is place to be. The 2 Meter SSB specialist with limited resources will develop a general knowledge of physics, meteorology and astronomy in order to produce good results. The serious enthusiast can create their own opportunities with a top-notch Big-Gun station. You can do a little or do a lot.
So what does 2 Meter SSB offer to the DX’ing community? Many special propagation modes are available: Earth-Moon-Earth (EME), Aurora, Sporadic Es and FAI, Meteor Scatter, and the most common phenomena, Tropspheric Ducting better known as Tropo.
Earth-Moon-Earth, known better as EME, due to the shear difficulty and distance that the signal travels requires the best equipment and antennas. But, a combination of several first-class stations and the development of the PC Soundcard digital modes, more simple set up stations are now completing their first QSO’s on EME. WSJT is several digital modes developed by Nobel Prize winner Joe Taylor, K1JT. WSJT stands for “Weak Signal by K1JT”. Earlier versions that developed into one mode called JT65, is the standard for EME work and single Yagi stations have used completed EME QSO’s. Many of the better equipped stations still use CW, and on rare occasions SSB on EME. Overall, if you intend to regularly and successfully try EME, expect to make a serious financial commitment to equipment and construction of an antenna arrays.
Aurora is a special propagation mode that is a result of the severe solar storms that are created by the Sun. During the entire Solar Cycle, sunspot regions form near adjacent Coronal Holes. As these regions develop, they often produce solar flares. Most of them are weak and due to the fact that the sun rotates, most are not pointed directly at the Earth. Every now and then, a major region facing the Earth produces a powerful flare. X-Class flares, the most powerful ones kill HF propagation. It is not the flare that produces Aurora, but it is the Coronal Mass Ejection (CME) that follows it that will create the magnetic disturbance one to two days later. This creates the strong Aurora Borealis that reflects 2 Meter signals. The stronger the magnetic disturbance, the further south it works.
Typically, only the northern most states experience it on a regular basis. The southern states do experience it around once every couple of years to once a year. A good skill of CW is needed for Aurora. SSB contacts occur, but are rare overall. Signals are the result of backscatter (Yagis are pointed NW to NE) and sound raspy with a buzzing sound. Digital modes are ineffective. It requires high gain Yagi antennas with reasonable power (150 watts+), but has been completed with low power and low gained antennas. Florida, South Texas and Central California worked Aurora a little over a year ago.
Meteor Scatter was once considered a propagation mode to be used only during major annual meteor showers. Usually once or twice in a lifetime does a Meteor Storm (as in November 2001 and 2002) provide one a continuous 2-Meter DX event. Generally it required a pre-established schedule using timed transmissions between Ham radio operators. Only at the meteor shower’s peak at the showers optimum direction for scatter, plus a lot of luck, did a non-coordinated CW or SSB contact work. The digital modes developed by K1JT’s WSJT changed it all. Using the WSJT mode known as FSK441A, many are now completing random QSO’s on 2 Meters and scheduled QSO’s are now being completed with ease during non-Meteor shower times. In the past few years, several Hams have accumulated over 40 states and nearly 300 Grid Squares (the pursuit of Grand VHF DX Award VUCC) using the WSJT FSK441 digital mode.
Now we enter the propagation modes that are a result of Ionospheric and Atmospheric conditions.
Sporadic Es are commonly referred to as “Short Skip”. Those who have operated 10-Meters, 11-Meters (CB) and 6-Meters, often make DX QSO’s by using this propagation mode. When the Maximum Usable Frequency (MUF) for the E-layer of the ionosphere reaches 144 MHz, the docile and quiet 2-Meter band becomes a beehive of DX activity. The old saying that “you can work them with 5 watts and a wet noodle” is not that farfetched. This mode primarily occurs from the first week of May to the second week of August. A second season occurs from late November to late January, but is extremely rare if it reaches a 144MHz MUF.
The late Spring to mid-Summer season is when to concentrate on working Es. Using other tools, the Internet links and software can prepare you for the opening. Most times, Es propagation occurs first on lower frequencies (6 & 10 Meters), then intensifies before it becomes a 2-Meter opening. Monitoring TV channels 2 thru 7, the FM Broadcast band and the Aircraft band will help one know where the optimum direction of the opening will occur. Most times a positive identification of a Channel 6 TV station (87.5MHZ) or a DX FM Broadcast station will be the direction of the eventual 2-Meter opening. If you hear the DX on your favorite 2-Meter repeater, you have been missing the opening for quite some time.
Experienced Weak Signal enthusiasts listen for the increased noise levels associated with the band opening. Openings can vary in strength and length of time. It can be like Meteor Scatter or can close and open continuously for many hours. When intense, many QSO’s occur with low power and simple antennas. Still, the high powered and sophisticated arrayed stations will have the greater results. Once every ten to eleven years, in any one given area will experience a “Super” opening. Last year, the East coast experienced one. In 1987, North Texas had a 2-Meter E opening simultaneously to both the East and West Coasts and a few QSO’s were completed between the coasts (double-hop). It is becoming more common for the MUF to make it to 222 MHz, as a few more Hams are now active there. Once you have worked 2 Meter Es, you will be hooked. There is not anything more exciting and exhilarating in all of Ham radio.
The most active DX propagation mode is Tropo. Tropo is the result of specific weather events. It is also the easiest of the DX modes to predict. As long as you can decipher weather maps that show surface and upper air pressure patterns, you can have an edge in working DX by being ready. The same tools used in operating Sporadic Es are available for Tropo, plus a few additional ones. Tropo is caused by one simple weather phenomena, significant (area and in height) temperature inversions. Tropo can occur at any time and place, but tends to favor early Spring to Mid-Fall. Close proximity to large bodies of water (Gulf of Mexico, Pacific and Atlantic Ocean, and Great Lakes) help and influence it, but is not always required. Monitoring VHF & UHF TV, the Internet links and seeing large patches of “false echoes” on the National Weather Service Radars easily confirm these conditions. Major Tropo events require a stable atmosphere. Stormy weather only create localized and short events.
Major events are directly caused by the strong influence of an Upper-Air High Pressure system (15,000-35,000 feet high) ridged over a surface High Pressure system. The area influenced occurs along the southwest, west and northwest areas of the surface and Upper Air High Pressure centers (the warm sides). A lack of upper air winds (indicating high pressure) helps cap the atmosphere. Temperate increases and the dew point decreases, resulting in a strong inversion to bend VHF and UHF signals. A hazy day, a warm foggy morning, heavy dew and a sudden increase in the daytime temperature from the day before are alerts to a possible Tropo condition.
The following Tropo event occurred in early September of 2003:
The first Canadian based cold front followed by a strong surface high pressure system of the late summer/early fall moved through the eastern half of the United States. Once the front reached the Gulf of Mexico and the Atlantic Ocean, it stalled out just off shore. Meanwhile, a northward moving hurricane was situated between Bermuda and the U.S. East Coast. The hurricane had pushed the seasonal Bermuda High (the Upper Air one) well into the eastern half of the United States. Its western edge was located well into southern Texas to Nebraska and Iowa. Upper air winds in the eastern half of the U.S. were non-existent. For two evenings, successful SSB and CW QSO’s were completed by many moderate to low powered Hams for distances just short of 1600 miles! A number of 30+ year old North American Tropo Continental DX records on 144 MHz and 222 MHz were broken. Most of the New England States completed QSO’s with Texas, to Oklahoma, to Iowa on 2 Meter SSB. This was a once in a lifetime event, but many other long distance ones occur each year.
DX Recap
Persistence and patience will always pay off. You won’t get DXCC, WAC or WAS without doing EME, but a 150 watts, a high performance single Yagi at a height above the homes and trees, fed with an RG8 style low loss feedline will produce excellent results. Your author, using the setup just mentioned, has worked 42 states and 193 Grid Squares from the Dallas/FortWorth Metroplex in a little over 20 years of what can be called a casual on and off operation. All the states and 190 grid squares was worked by non-scheduled QSO’s and only using terrestrial propagation modes (No EME). Many DX QSO’s were completed with 25 watts and a simple 4-element Yagi.
A large number of Weak Signal enthusiasts have put together high powered stations, driving large multi-arrayed EME (long boomed) antennas. Certainly, they produce impressive numbers, but they also give many less powerful stations the opportunity to work DX. You might complain that they hog the band, but they draw attention to the DX. You can smile as you think of manure attracting flies. Thank them for being there. Still, much pleasure can be obtained when you capture one over 1500 miles away with 25 watts and a small Yagi. Just remember that the better the station, the better the results. The less, the harder you will work and the smaller the results. Great rewards nonetheless.
Who promotes 2-Meter Sideband?
There are many fine VHF organizations, but only one radio club promotes it exclusively. That organization is the Sidewinders on Two Radio Club, known as SWOT. The club was formed in the mid-1970’s and has had nearly 3,500 register members over its history. Its roots started in North Texas, has members worldwide and a large Chapter in Northern California. SWOT promotes 2- Meter Sideband, CW and Digital operations and publishes a monthly bulletin to inform and promote. You can find SWOT on the Worldwide Web at the SWOT Hompage: www.swotrc.net, or the SWOT Yahoo Group Page: http://groups.yahoo.com/group/sidewindersontwo/. Both Websites contain membership information, past Bulletins, DX Web links and audio examples of several major 2-Meter band openings. All are invited to visit, and we strongly urge you to join SWOT in order for us to share information with the Ham Radio community. Annual dues are only $12 a year. You will be issued a unique number (like 10-10, QRPARCI or SMIRK) and it is yours for life.
Look for one of our Nets and check in. As long as you are using a horizontally polarized Yagi and a reasonable power level, you should reach these Nets on most occasions. At least you can be relayed in. We would like see more activity from West Texas. Our Nets are available to all, you do not need to be a SWOT member, but hope you consider it. We also would entertain the creation of any SWOT Net and would do our best to promote it. There has been discussions of the development of a PSK31 (SSB only) and CW Nets, but these have yet materialized. Interested in starting one of these? Let us know.
We hope you join us on 2 Meter Sideband and look forward to hearing from you all.
73’s and Good DX
Art Jackson – KA5DWI
SWOT #2497, Chairperson and Former Bulletin Editor
2-Meter VUCC #237