[GCARC] EME contest operation update

[Jon Pearce]

Here's an update on our Earth-Moon-Earth (EME) operations for the ARRL EME Contest this weekend (October 10–12, 2025). The contest kicks off at 8 PM EDT on Friday night, but the Moon won't rise in our area until about 8:40 PM, so the EME team plans to start setup sometime after dinner. The Moon will be low at first, with optimal QSO conditions beginning after about 11 PM when it reaches around 30° elevation. The peak window—1 to 3 AM—offers the best chances, with the Moon at 50–60° elevation for stronger signals and less fading, and will also be visible over Europe allowing those QSOs. Whether we'll operate that late depends on the team's stamina, so it's a judgment call each night. If you're keen on EME, plan to join from about 8 PM onward, potentially into the early morning.
Saturday morning ops will be less ideal than evenings due to higher solar interference (about 2–3 dB more noise, making weak signals harder to decode), but some QSOs are still possible. The Moon sets at 12:47 PM that day, so this could be a good morning to check out the station if you prefer daytime and will be satisfied with less activity. I'll be at the clubhouse by 9 AM Saturday.
Note that the forecast calls for precipitation Saturday night, and our dish and rotator can't get wet, so we may not operate at all. The Moon rises at 9:36 PM Saturday but if rain threatens we might wrap up after moonset around noon that day. And the dish is susceptible to wind loading so if it's really windy we may not be able to operate at all.
Finally, remember that EME excitement lies in the results, not the moment-to-moment action—it's slow-paced, with weak signals often invisible on the spectrum and QSOs often taking 10+ minutes of waiting. Also remember that this is only our second time operating EME with this equipment and dish, and the first time with everything apparently working properly. Much about EME operation is experimentation and we're all learning as we do it. But completing a contact over a 500,000-mile round trip is really pretty cool DX so come out if you'd like to see it happen.
73 de Jon WB2MNF