Dave Swanson, KG5CCI reported that on February 10th, at 2009UTC he made a scheduled contact with Eduardo Erlemann, PY2RN, using AO-7 Mode B, from Shinnal Mountain just west of Little Rock, Arkansas. His 10 digit grid locator for the contact was EM34ST20SC, and Eduardo’s station is located at GG66LW77JQ in Vinhedo/SP, Brazil. Using this mapping website for reference, this equates to 8030.895 km which we believe to be a new record for AO-7 Mode B.
Dave wrote, “Back on January 24th, I was on an AO-7(B) pass looking for Gustavo, PT9BM. While not a record distance, Gustavo’s QTH is just shy of 7500km away from me, so I was up on my mountain, specifically in a spot with great a great southeastern view of the Horizon. As the bird came into view, while scanning the passband, I heard Eduardo, PY2RN, calling CQ. I tried to answer him, but his signal disappeared quickly after that. I went had a great QSO with Gustavo, and didn’t think anything else of it until later that night when I decided to look up the new station I had heard. To my astonishment, Eduardo was 8030km away, which was way beyond the theoretical range AO-7, even with elevation assistance. I promptly emailed Eduardo and we both agreed to try and make a contact, even though the math said it shouldn’t be possible.
“At this point the random luck that had let me hear Eduardo on the 24th seemed to elude us. We attempted contacts on the 26th, 28th, and 30th all to no avail. After recalculating windows, our next shot was on February 8th. WinListen (from Sat32pc) calculated a 3 second window on the 8th, followed by 5 seconds on the 10th. The day of the 8th came, and we prepared for the attempt. Murphy once again seemed to haunt us though, as we successfully heard the calls and grids of each other, but strong CW QRM was hitting the bird so hard that the intelligibility was low and, more importantly, neither of us had a camera running. We decided to not count the QSO due to these reasons. The good news was though, we both heard each other (the first time that had happened) and our frequency coordination was spot on. We knew it could be done, we just needed a little luck.
“Finally, on February 10th, we got a bit of a break. We had already determined that 5 seconds was simply not enough time to do a proper “QSL thanks for the grid, have a great day” type of chat, so we both agreed to simply repeat ‘your call / my call / grid / report’ rapidly, much in the same way a digital or contest contact is made. At 2009UTC, both stations cleanly heard the others call and grid, completing the contact. It was extremely rapid, and very weak, but clear. Eduardo’s side of the QSO turned out way better than mine did, and he has uploaded a recording of it to youtube: https://youtu.be/pTGSlaY7K7A
“After all my work towards low-elevation contacts from mountain-tops, I think this is approaching the limits of what can be done on AO-7. This was by far the hardest sked I’ve ever attempted, and with the contact window measured in mere seconds, it leaves absolutely no room for error. Had I not heard Eduardo’s call at random on the attempt with Gustavo, I doubt I would have even pursued this as something that was possible. That said, wow.. what a rush
“Big thanks to Eduardo, PY2RN, for humoring my obsession with making ultra long-distance QSOs on the birds, and for sticking with it until we finally made it work. Good DX my friend. Also thanks to Gustavo, PT9BM for persuading me to point my arrow to the South, and Drew, KO4MA for acting as a spotter during one of the passes to see just how far apart we were from each other. Appreciate it guys.”
-Dave, KG5CCI