Moon-bounce from Tristan da Cunha
Report and photos from Lance Collister
Lance Collister in the Tristan'Radio Shack' on 19th September 2024
Licensed Amateur Radio Operators ("hams") around the world try to collect contacts with as many countries and remote islands as possible.
This becomes more difficult on the higher frequencies, such as VHF bands, where the coverage is mostly local, or line of sight. However, with specialized equipment and large enough antennas, VHF signals can be sent to the moon and back. In that way, people around the Earth can be contacted using the very faint "moon-bounce" signals which are reflected back to Earth. Nobody had ever operated EME (Earth-Moon-Earth) from Tristan before, so most parts of the world never had a chance to contact this rare and remote spot. Of course, with EME contacts, the distances from Tristan are all really about a half million miles, and it takes between two and three seconds for the weak signals to return to Earth!
Lance's aerial set up to aim VHF signals at the moon
I chose the lowest VHF band at 50 MHz to activate Tristan for the first time on EME. After trying to get here for several years, I finally was advised of a last-minute cancellation and availability of a berth on the SA Agulhas II from Cape Town. I jumped at the chance to travel down here and set up a 50 Mhz EME station on Tristan. After a couple weeks of operation, I had contacted 136 stations around the world by EME. They included the first ever stations from North America to ever contact Tristan on VHF, as well as more distant stations in Japan and Alaska. And since now is the peak of solar activity during the current 11-year solar cycle, there was an opportunity to contact another 348 stations in Europe and 2 in South America by bouncing my signals off the ionosphere.
The aerial at dusk
We did have some high winds and storms, but the weather at times was actually very nice. I was fortunate that the large antenna successfully withstood what can be very challenging weather conditions this time of year. It was a very successful trip in terms of the radio accomplishments. But it also was a fantastic visit with very friendly residents in a spectacularly beautiful place! I will miss this very unique place and its people.