Try, try, try to understand, it’s a magic band.
(Apologies to the rock band Heart–too bad they didn’t know about 6 meters.)
“The Magic Band” is a phrase used to describe the joy and heartbreak hams experience on six meters. Fans of the 50 MHz frequency band realize it may be frustratingly quiet at times, but can suddenly become alive with a flurry of activity. Signals appear to come out of nowhere, then they mysteriously vanish–like a David Copperfield disappearing act.
You can do almost anything on six meters that you would do on any other HF band. Hams have earned WAS, WAC and DXCC awards on six. At times, six meters can sound like a contest weekend on 20 meters, filled with signals and pileups galore. What makes it so different from the HF bands is that you never know when this excitement will come.
Next Stop, the Six Meter Zone
On six meters you are traveling through another dimension, a journey into a wondrous land whose boundaries are that of 50-54 MHz. It’s on the edge of HF and VHF, and can behave like either at any moment. This band includes all modes of amateur communications: phone, CW, SSTV, digital, remote control, beacons and repeaters. It’s divided into segments, according to a band plan, for minimal interference between the different modes and uses.
Many of the newer HF rigs come with six-meter capability built in, something that has become common in the last two decades. Why? One answer might be to provide an on-ramp to more serious participation in VHF operation. Another is to attract those with Technician licenses who can use the entire band and all its modes–with the possibility of working some DX as well.
The upcoming summer months are perfect for getting your feet wet since there are so many propagation opportunities available. In most cases, you just select six meters on your existing HF rig. Need an antenna? A simple dipole takes up less than 10 feet of space, and most Moxons and aluminum Yagis are relatively compact and lightweight. J-poles and ground planes are commonly used for local communication.
If anything is happening on six meters, you’ll most likely hear it first from 50.100 to 50.125 MHz–the DX window that includes the traditional 50.125 calling frequency. Once the band is open, move above the calling frequency for QSOs. Activity up above 50.250 usually indicates good openings. Another clue is if you are hearing very strong E (short) skip on 10 meters, chances are very good that six meters is open in the same direction. E-skip is typically between 700 and 1400 miles per hop.
Beacons provide early warning for six-meter band openings. They’re used to check propagation on six meters so operators can decide whether the band is useable at that moment to the part of the world where the beacon is located. Beacons traditionally operate in the lower part of the band from 50 to 50.080 MHz.
DX clusters can tell you what stations are on the air and their locations in real time. Most have filters that will let you select bands and modes. Some examples on the Internet include DX Summit, DX Watch, and DX Maps.
First Contact
One piece of information usually exchanged during a QSO is your grid square. The Maidenhead grid-square system is universally used as a locator system by VHF, UHF and microwave operators. This system divides the world into 324 zones designated as fields. Each field is divided into 100 locator squares (there are 32,400 grid squares in all). Each grid square is 1 degree latitude and 2 degrees longitude in size, which covers an area of about 70 x 100 miles in the U.S.
VHF operators collect grid squares like HF operators collect countries. Many work toward the ARRL’s VHF-UHF Century Club (VUCC) award, which requires confirmed contacts with 100 grid squares. During VHF contests, some ops go on Gridexpeditions to put rare grid squares on the air. Others become rovers to operate from several grids during the contest. Just as states or countries serve as multipliers for HF-contest scores, grid squares are the multipliers for VHF-contest scores.
Propagation
Six meters offers nearly every kind of propagation known. Ground wave propagation is generally 50 miles or more, great for local nets. But when other factors are involved, range can increase considerably.
At the peak of a sunspot cycle when the solar flux rises to between 150 and 200, the F-layer skip on HF can provide worldwide contacts on six meters. If the flux goes significantly above 200, DX work on six meters can even become fairly reliable. Propagation modes familiar to VHF operators, such as sporadic-E, auroral, meteor-scatter, trans-equatorial and tropospheric ducting, have been used on six meters as well.
Sporadic-E: This is the most common propagation available for six-meter DX. Peaking around the solstices, this mode of propagation can provide contacts over a few hundred miles, a couple thousand miles, or even more with a double-hop. Because the E layer in the atmosphere becomes very active close to mid-summer, it is possible for your signal to be bounced multiple times, resulting in USA-EU EU-Asia USA-Asia communications. Imagine a JA QSL card for 50 MHz–cool!
Fortunately, sporadic-E comes back every year, even during the sunspot minimum. The E-skip season runs from May to July, with another shorter peak in December and early January. But this propagation mode can appear at any time. A sporadic-E opening typically lasts for a few hours.
F2 layer: The fun really begins at the peak of a sunspot cycle when solar activity ionizes the F2 layer sufficiently enough to allow the global communications abilities on six meters that we enjoy on the HF bands. We have a few years to Cycle 25 maximum, but hopefully it will be worth the wait.
Trans-Equatorial Propagation: TEP provides propagation North-South/South-North on either side of and across the equator to about 1,500 miles or more. Typically, it occurs in the late afternoon or early evening during spring and fall. High levels of ionization are present at the equator because it receives the maximum radiation from the sun. A high electron peak is present on either side of the geomagnetic equator at latitudes of around 10° to 20°.
Meteor Scatter or Meteor Burst: This communication utilizes the dense trails of ionization left by meteors as they enter the upper layers of the Earth’s atmosphere. The trails can reflect VHF and sometimes UHF signals, but they are only present for a short time. Specialized digital transmission modes have been developed especially for meteor scatter operation, with signals traveling up to 1,250 miles.
Tropospheric Ducting: This occurs when a radio signal is reflected off of the troposphere and continues on a path that allows the signal to travel much farther than it normally would. This happens when the temperature in the atmosphere experiences a shift called an inversion–relatively common during summer months and especially during evenings in periods of stable and nice weather. Radio waves have been able to travel in excess of 1,000 miles because of tropospheric ducting.
Aurora Borealis (Northern Lights): The aurora is capable of reflecting signals from the HF bands through 70 centimeters. Interestingly, if the aurora is strong enough, sporadic-E develops, which is known as Auroral-Es. Morse code (CW) or digital modes (such as FT8 and others) are viable under these conditions, but the voice modes of transmission (SSB, AM and FM) can be strongly scrambled and unintelligible.
The Six Meter Challenge
If you haven’t tried six meters, do it!
During magic band openings, I would compare the sudden six-meter ham band activity to a flash mob. The 50 MHz frequency band opens, then starts to boil over with activity for a few minutes–sometimes hours depending on propagation. It’s both fascinating and mind-boggling to witness such an event, not to mention the adrenaline rush. We’re suddenly compelled to complete as many QSOs as possible during these brief moments.
