VHF/UHF weak-signal operators across North America are making final tests on their stations in preparation for the ARRL August UHF Contest, which is coming up over the weekend of August 4-5. Most VHF+ weak-signal operation takes place on the two lowest bands of the VHF spectrum -- 6 and 2 meters. But according to ARRL Contest Branch Manager Sean Kutzko, KX9X, there is a lot of activity that takes place above 144 MHz in the UHF portion of the radio spectrum and beyond. This contest will focus on 220 MHz and above. There will be lots of activity, and hopefully lots of propagation, too!

“With much of the nation in the midst of a summer heat spike, high-pressure zones can begin to form in the atmosphere,” Kutzko explained. “If they stick around long enough -- and are stable enough -- enhanced propagation can occur in the troposphere, extending the normal usable range of UHF+ frequencies from line-of-sight to several hundred miles. Several cloudless days with very little wind are signs that enhanced tropospheric enhancement could be coming your way. A great site to watch for tropospheric enhancement is William Hepburn’s tropospheric ducting forecast page.”

If you’ve never made a contact in the ARRL UHF Contest, this is a great time to start! According to Kutzko, a good beginner’s station consists of a 220 MHz FM radio with a vertically-polarized antenna, along with a 432 MHz rig that can work SSB/CW and a horizontally polarized antenna, such as a Yagi or loop. “While the lowest band permitted in the UHF Contest is 220 MHz, the most-active band is usually 432 MHz,” he said. “Many of the ‘DC-to-Light’ rigs being offered today have 432 MHz in them, and antennas are reasonably small. There are many inexpensive commercial Yagi or horizontal loop antennas on the market, or if you prefer to build your own, you can find easy homebrew UHF antenna plans in the ARRL Antenna Book and The ARRL Handbook.”

If you live near a large population center, Kutzko explained that 220 MHz FM will see lots activity. “Monitor the national FM calling frequency of 223.5 MHz for activity, but be prepared to move off the calling frequency should conditions warrant,” he said. “For 432 MHz SSB/CW, 432.100 MHz is the frequency to monitor. Again, be prepared to move off the calling frequency if there are excellent conditions; too many people on the calling frequency makes for some tough conditions to copy signals. It’s bad form to monopolize the calling frequency.”

Kutzko noted that anyone can operate from their home, but why not think outside the box? “Because antennas are so small and portable (along with many of the rigs), operating from a hilltop is very easy,” he said. “Equip yourself with 10-15 feet of mast and set it up next to your car on a high point in your area and you’ll be in business! The contest exchange is simply your Maidenhead grid square. You can even be a ‘Rover’ and operate from your car from more than one grid square if you want!”

The ARRL August UHF Contest runs from 1800 UTC Saturday, August 4 through 1759 UTC Sunday, August 5. Complete rules and entry forms may be found here. All logs must be e-mailed or postmarked no later than 1800 UTC Tuesday, September 4, 2012. Paper logs can be sent to August UHF Contest, ARRL, 225 Main Street, Newington, CT 06111.