Earth-Moon-Earth Contesting
Hardware, Software & Activities
Bouncing Signals Off The Moon :
The Coolest Club Activity You Haven’t Tried Yet
By Jon Pearce WB2MNF
The Coolest Club Activity You Haven’t Tried Yet
By Jon Pearce WB2MNF
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Once again, on the night of Saturday, November 8, 2025, our intrepid EME team - Al Arrison KB2AYU, Frank Romeo N3PUU, John O'Connell K2QA, and myself - set up the Club’s 1296 MHz dish and successfully bounced signals off the moon during the second weekend of the ARRL EME Contest. Al, Frank, and John had just finished a brutal day of trench-digging for the lightning protection project and had barely enough energy to operate the station, yet they persevered until almost midnight. Thanks to the permanent 2¼-inch steel pipe mount set in concrete (a big improvement over the old tripod) and the cables Al had already run under the Clubhouse, setup took only about 20 minutes. The contest had started Friday |
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night in the rain, so we waited until Saturday around 9 PM when the moon cleared the Clubhouse and gave us a clear shot.
Using the EME web chat room for coordination, we worked stations all over the world - some with huge dishes and massive power, others running more modest setups like ours. We even heard our friends at W2ZQ (the DVRA station in Trenton) both via moonbounce and directly on the ground (the terrestrial path had no 3-second delay, which is how we could tell).
As the four of us sat in the Clubhouse that night, we talked about something that comes up every time we do EME :
We get it - hanging around the Clubhouse late on a Saturday night isn’t everyone’s idea of fun. But we also want to be crystal clear :
You do NOT need to be an expert. You do NOT need to touch a knob or key a microphone if you don’t want to. You’re absolutely invited to just come watch, ask questions, and see what it’s all about.
The whole point of having a big Club with great facilities is so that anyone who’s curious can try something new without feeling intimidated. EME might seem like rocket science (well, it kind of is…), but it’s also just a bunch of hams pointing a dish at the moon and making contacts. The only way to learn is to show up and see it happen.
That night we added 6 more QSOs, bringing our two-weekend total to 11 contacts - a solid score for a Club station of our size. We’ll be back working the moon next year, improving the station and operating more often.
We’d love to have you with us - whether you’re ready to participate or just want to watch the signals come in. No experience required, just curiosity.
Hope to see you at the next one!
Using the EME web chat room for coordination, we worked stations all over the world - some with huge dishes and massive power, others running more modest setups like ours. We even heard our friends at W2ZQ (the DVRA station in Trenton) both via moonbounce and directly on the ground (the terrestrial path had no 3-second delay, which is how we could tell).
As the four of us sat in the Clubhouse that night, we talked about something that comes up every time we do EME :
- Lots of members tell us “Moonbounce sounds really cool!” - but very few actually come out to see it in person.
We get it - hanging around the Clubhouse late on a Saturday night isn’t everyone’s idea of fun. But we also want to be crystal clear :
- Every Club member is welcome to join us for EME (or satellites, VHF contests, Field Day - anything the Club does), no matter how “technical” or complicated it looks from the outside.
You do NOT need to be an expert. You do NOT need to touch a knob or key a microphone if you don’t want to. You’re absolutely invited to just come watch, ask questions, and see what it’s all about.
The whole point of having a big Club with great facilities is so that anyone who’s curious can try something new without feeling intimidated. EME might seem like rocket science (well, it kind of is…), but it’s also just a bunch of hams pointing a dish at the moon and making contacts. The only way to learn is to show up and see it happen.
That night we added 6 more QSOs, bringing our two-weekend total to 11 contacts - a solid score for a Club station of our size. We’ll be back working the moon next year, improving the station and operating more often.
We’d love to have you with us - whether you’re ready to participate or just want to watch the signals come in. No experience required, just curiosity.
Hope to see you at the next one!
W2MMD EME Contest Operation Recap - October 2025
By Jon Pearce WB2MNF
Earth-Moon-Earth (EME) communication is a fascinating weak-signal mode on VHF/UHF bands. This year, several Club members expressed interest in trying it. Our EME team included Al Arrison KB2AYU, Frank Romeo N3PUU, John O'Connell K2QA, and me, with Mike Thompson KG4JYA assisting in setup and Marc Federici WM2Y joining for late-night operations during the contest.
Radio Equipment
Several years ago when equipping the VHF room we selected gear suitable for EME, including the Gemini 23 amplifier, which outputs 250 watts on 1296 MHz. Last year, we added a 2.4-meter collapsible mesh dish from SubLunar Systems with accompanying mounting tripod and tested it during the November 2024 EME contest. There we faced two major issues : the amplifier shut down with a "High SWR" error - even when connected to a dummy load - making it unusable, and manual dish rotation proved too cumbersome, highlighting the need for automated tracking.
In the months since, Al diagnosed the amplifier and adjusted a potentiometer to fix the SWR sensitivity, restoring full functionality. We also acquired the matching rotator, tripod, and controller from SubLunar for automatic moon tracking, which eliminated manual adjustments every 15 minutes. The initial mounting on the tripod was time-consuming and imprecise so we resolved it by embedding a 3-foot PVC pipe in concrete outside the Clubhouse VHF room window. A steel pipe slides into it, extending 4 feet above ground, providing a stable base for the rotator. This upgrade dramatically cut setup time.
In our previous operation we found that the dish front-loaded the rotator significantly indicating the need for a counterweight, which apparently had been omitted from the dish assembly instructions. Fortunately remediation was simple using a piece of scrap aluminum tubing from the heap next to the shed and mounting four “precision-weighted” bricks on the tubing with hose clamps. We adjusted the brick position to get approximately even balance on the rotator, which significantly lightened its load on the elevation rotator.
Connecting the Hardware
Feedline losses are high at 1296 MHz, so we optimized the setup to keep them minimal. Last year, we positioned the amplifier, transverter and rotator controller outside the VHF room window, feeding the transverter at its 28 MHz IF input. This shortened the 1296 MHz run to the dish. This year Al installed ½-inch hardline from the VHF room's far side to the dish, connecting it to the feedhorn via short flexible coax.
A front-mounted relay handles switching : It routes the feedline between transmit and receive ports on the feedhorn while also isolating the preamp from the antenna during transmit, also bypassing it to a dummy load to avoid RF damage.
The amplifier is rated for 200 watts and seems to put out that much power even with the extended transmit times in Q65 mode. Accounting for feedline losses, we estimate ~165 watts reaches the dish. With the dish's ~30 dB gain, effective radiated power (ERP) is roughly 9–10 kW. However, the moon spans only 0.5 degrees, and our 4-degree beamwidth directs just 1.6% of that power onto it so only about 175 watts actually reach the moon’s surface.
Software
We used WSJT-X with the Q65 mode, a digital scheme designed for weak-signal work like EME. Q65 employs 65-tone frequency-shift-keying (FSK) plus a sync tone for precise timing and frequency alignment, ideal for handling rapid signal fading from libration and Faraday rotation that are present in EME operations.
Key features include :
This sensitivity allows modest stations like ours to complete QSOs over the 500,000-mile path. We mostly used 30C (30-second transmits) but switched to 60C when needed to match calling stations. These longer sequences make QSOs time-intensive but are essential for many EME setups.
QSO Spotting on HB9Q
Internet spotting via the HB9Q website is vital for EME success. Operators transmit on a set frequency (e.g., 1296.085 MHz) in a specified Q65 mode (B or C) and period (30 or 60 seconds), then post their details on HB9Q. Listeners tune to that frequency/mode and respond if they decode the CQ.
Without this coordination, QSOs are virtually impossible - signals often lie below the noise floor and aren't visible on waterfalls, with modes indistinguishable without prior knowledge. Pre-WSJT, EME relied on CW/SSB, demanding much stronger signals.
The Contest
The contest began at 8:00 PM EDT on Friday, but moonrise at the Clubhouse wasn't until ~8:40 PM. We started setup around 7:00 PM and finished in about 30 minutes after some troubleshooting : the dish was initially mounted on the rotator backward and elevation failed due to a quirky config error in the rotator controller that was fixed by Frank's quick correction.
At moonrise, the dish still aimed partially at the Clubhouse's east end, so we waited for it to move southward and rise. At that point we also had to monitor the beam path to avoid exposing anyone to the ~10 kW ERP during transmits since it was aiming at the front steps of the Clubhouse. Later outdoor movement was more possible as the moon rose and moved southward but we still needed to coordinate to avoid activity when transmitting.
We began with compass-based pointing but switched to visual aiming once the moon was overhead (visible through the mesh). The Wintrack controller provided precise tracking, ending manual tweaks.
By ~10:30 PM, with the dish still low and partially blocked northward, we decoded signals and answered a CQ from OK1DFC who was using 8- and 10-meter dishes, completing our first QSO in this setup. As the moon rose, more stations appeared on the waterfall and HB9Q requests rolled in. We logged 5 QSOs total before packing up at ~12:30 AM.
Saturday Attempts
Saturday's focus was demonstrating the station to daytime Club members unavailable for nights. We anticipated challenges : daytime sky noise adds 2-3 dB limiting success. Still, it might let visitors see the gear in action.
Rain was forecast for evening, so we planned teardown post-moonset. But light rain arrived early (~9:00 AM). We repositioned the dish and listened but heard nothing - not even HB9Q-reported signals - so we shut down and stowed gear by ~1:00 PM. The contest ran through Sunday, but rain precluded further ops (dish/electronics aren't weatherproof). Luckily, everything packs compactly and now waits in the VHF room corner until better storage is arranged.
Conclusions and Next Steps
The operation succeeded overall - no major equipment or procedural flaws emerged, though a few team members noted areas for procedural research. Extending into early morning could have added QSOs; we'll aim for that next time.
The next EME contest is November 11-12. Mark your calendars for potential participation - we hope for clear weather and strong conditions!
By Jon Pearce WB2MNF
Earth-Moon-Earth (EME) communication is a fascinating weak-signal mode on VHF/UHF bands. This year, several Club members expressed interest in trying it. Our EME team included Al Arrison KB2AYU, Frank Romeo N3PUU, John O'Connell K2QA, and me, with Mike Thompson KG4JYA assisting in setup and Marc Federici WM2Y joining for late-night operations during the contest.
Radio Equipment
Several years ago when equipping the VHF room we selected gear suitable for EME, including the Gemini 23 amplifier, which outputs 250 watts on 1296 MHz. Last year, we added a 2.4-meter collapsible mesh dish from SubLunar Systems with accompanying mounting tripod and tested it during the November 2024 EME contest. There we faced two major issues : the amplifier shut down with a "High SWR" error - even when connected to a dummy load - making it unusable, and manual dish rotation proved too cumbersome, highlighting the need for automated tracking.
In the months since, Al diagnosed the amplifier and adjusted a potentiometer to fix the SWR sensitivity, restoring full functionality. We also acquired the matching rotator, tripod, and controller from SubLunar for automatic moon tracking, which eliminated manual adjustments every 15 minutes. The initial mounting on the tripod was time-consuming and imprecise so we resolved it by embedding a 3-foot PVC pipe in concrete outside the Clubhouse VHF room window. A steel pipe slides into it, extending 4 feet above ground, providing a stable base for the rotator. This upgrade dramatically cut setup time.
In our previous operation we found that the dish front-loaded the rotator significantly indicating the need for a counterweight, which apparently had been omitted from the dish assembly instructions. Fortunately remediation was simple using a piece of scrap aluminum tubing from the heap next to the shed and mounting four “precision-weighted” bricks on the tubing with hose clamps. We adjusted the brick position to get approximately even balance on the rotator, which significantly lightened its load on the elevation rotator.
Connecting the Hardware
Feedline losses are high at 1296 MHz, so we optimized the setup to keep them minimal. Last year, we positioned the amplifier, transverter and rotator controller outside the VHF room window, feeding the transverter at its 28 MHz IF input. This shortened the 1296 MHz run to the dish. This year Al installed ½-inch hardline from the VHF room's far side to the dish, connecting it to the feedhorn via short flexible coax.
A front-mounted relay handles switching : It routes the feedline between transmit and receive ports on the feedhorn while also isolating the preamp from the antenna during transmit, also bypassing it to a dummy load to avoid RF damage.
The amplifier is rated for 200 watts and seems to put out that much power even with the extended transmit times in Q65 mode. Accounting for feedline losses, we estimate ~165 watts reaches the dish. With the dish's ~30 dB gain, effective radiated power (ERP) is roughly 9–10 kW. However, the moon spans only 0.5 degrees, and our 4-degree beamwidth directs just 1.6% of that power onto it so only about 175 watts actually reach the moon’s surface.
Software
We used WSJT-X with the Q65 mode, a digital scheme designed for weak-signal work like EME. Q65 employs 65-tone frequency-shift-keying (FSK) plus a sync tone for precise timing and frequency alignment, ideal for handling rapid signal fading from libration and Faraday rotation that are present in EME operations.
Key features include :
- Selectable T/R periods : 15, 30, 60, 120, or 300 seconds.
- Sub-modes (A–E) with tone spacings from ~2.7 Hz (sub-mode A) to ~10.8 Hz (sub-mode E); sub-mode C (~5.4 Hz) suits 60-second cycles.
- For 1296 MHz EME, Q65-60C is standard, decoding down to -27.6 dB SNR (-30.2 dB with a priori decoding using known callsigns).
This sensitivity allows modest stations like ours to complete QSOs over the 500,000-mile path. We mostly used 30C (30-second transmits) but switched to 60C when needed to match calling stations. These longer sequences make QSOs time-intensive but are essential for many EME setups.
QSO Spotting on HB9Q
Internet spotting via the HB9Q website is vital for EME success. Operators transmit on a set frequency (e.g., 1296.085 MHz) in a specified Q65 mode (B or C) and period (30 or 60 seconds), then post their details on HB9Q. Listeners tune to that frequency/mode and respond if they decode the CQ.
Without this coordination, QSOs are virtually impossible - signals often lie below the noise floor and aren't visible on waterfalls, with modes indistinguishable without prior knowledge. Pre-WSJT, EME relied on CW/SSB, demanding much stronger signals.
The Contest
The contest began at 8:00 PM EDT on Friday, but moonrise at the Clubhouse wasn't until ~8:40 PM. We started setup around 7:00 PM and finished in about 30 minutes after some troubleshooting : the dish was initially mounted on the rotator backward and elevation failed due to a quirky config error in the rotator controller that was fixed by Frank's quick correction.
At moonrise, the dish still aimed partially at the Clubhouse's east end, so we waited for it to move southward and rise. At that point we also had to monitor the beam path to avoid exposing anyone to the ~10 kW ERP during transmits since it was aiming at the front steps of the Clubhouse. Later outdoor movement was more possible as the moon rose and moved southward but we still needed to coordinate to avoid activity when transmitting.
We began with compass-based pointing but switched to visual aiming once the moon was overhead (visible through the mesh). The Wintrack controller provided precise tracking, ending manual tweaks.
By ~10:30 PM, with the dish still low and partially blocked northward, we decoded signals and answered a CQ from OK1DFC who was using 8- and 10-meter dishes, completing our first QSO in this setup. As the moon rose, more stations appeared on the waterfall and HB9Q requests rolled in. We logged 5 QSOs total before packing up at ~12:30 AM.
Saturday Attempts
Saturday's focus was demonstrating the station to daytime Club members unavailable for nights. We anticipated challenges : daytime sky noise adds 2-3 dB limiting success. Still, it might let visitors see the gear in action.
Rain was forecast for evening, so we planned teardown post-moonset. But light rain arrived early (~9:00 AM). We repositioned the dish and listened but heard nothing - not even HB9Q-reported signals - so we shut down and stowed gear by ~1:00 PM. The contest ran through Sunday, but rain precluded further ops (dish/electronics aren't weatherproof). Luckily, everything packs compactly and now waits in the VHF room corner until better storage is arranged.
Conclusions and Next Steps
The operation succeeded overall - no major equipment or procedural flaws emerged, though a few team members noted areas for procedural research. Extending into early morning could have added QSOs; we'll aim for that next time.
The next EME contest is November 11-12. Mark your calendars for potential participation - we hope for clear weather and strong conditions!