IARU Reg I. UHF Contest 2024
After having such a good experience on Javořice, I was tempted to try the UHF leg of the IARU Region 1 contest as well.
In the weeks before the contest, my schedule was quite full, and I only managed to start building the antenna on Tuesday afternoon—with whatever materials I had lying around. I began with a simple dipole and coax connector (uhm… UHF purists, please don’t ask which type :] ). The rest of the antenna had to be finished overnight from Friday to Saturday.
Sometimes I push myself with these near-impossible deadlines—but honestly, if I had known what building a 70 cm antenna from scratch really involved, I wouldn’t attempt it again in such a tight time window. :)
My first mistake was thinking it would work to simply scale the antenna dimensions linearly. The second mistake was underestimating how much each element influences the overall resonance—and how confusing it is to tune an antenna without all the parts in place.
To cut a long story short: by Saturday at 11 PM, after just a few hours of sleep in the morning, I was still 100 km away from the contest site, working in my underground workshop... with no functional antenna—just a pile of aluminum junk and metal dust.
At least, I finally figured out the correct dimensions for the antenna. I was close to giving up, but decided to give it one last try. I pointed the beam toward the sky with the new dimensions, connected the VNA—and voilà! Return loss on 432 MHz finally looked decent. I grabbed the best coax I had: 7 meters of solid RG-213. Antenna setup: done!
The weather wasn’t exactly friendly—persistent, fine rain—so I decided to skip Saturday entirely, catch the first bus on Sunday morning, and make the most of the second half of the contest.
With that plan in mind, I literally threw all the gear into a bag and ran for the train. That evening, I also assembled a simple but surprisingly efficient and lightweight paddle keyer from an AliExpress kit.
The rain stopped on Sunday, though conditions weren’t ideal with all the wet trees and soaked forest around me. Unfortunately I did just a few contact to southeast, still, for just a few hours of operating and tight time schedule, I’m happy with the results.
LogCUAGN on 70 cm!