DSES participated in the ARRL Earth-Moon-Earth (EME) moon bounce contest last autumn. The contest was spread over 3 weekends. We participated in the weekend segments of October 10-11 and November 28-29. The ARRL has now posted the contest results.
We operated solely the 23 cm (1296 MHz band) with our 60-foot dish antenna. We used CW Morse Code and SSB Phone on the first weekend, and CW and Digital JT65 on the second weekend. We made 50 contacts over the two weekends. However, for contest scoring, stations we contact again over both weekends only count once. Therefore for scoring, we were credited with 36 contacts. Our team consisted of several operators: AA0L, KL7YY, WA2JQZ, and KC0HPN. Glen Davis also was crucial for adjusting our antenna pointing system and ensuring we were operational. (WD0CUJ and Michael Namieka also came out, and made a moon bounce test transmission, but didn’t make contest contacts.) And so we submitted our contest log in the All Mode, Multioperator, 1.2 GHz category, with our call sign K0PRT. Worldwide we came in 4th place in this category.
Rich Russel will have a poster presentation this coming Saturday, March 21, 2021 at HamSci – Ham Radio Science Citizen Investigation .
Rich will present his work about predicting the signal response of the 2017 total solar eclipse using the SID (Sudden Ionospheric Disturbance) radio telescope. The SID detects changes in ionospheric propagation of VLF signals due to solar activity. SID also measures changes at nominal sunrise and sunsets. Utilizing his historical data and geometry, Rich was able to predict what happened during the eclipse.
Please follow the links to read Rich’s poster presentation and to learn more.
On the weekend following this past Thanksgiving we participated in the second round of the ARRL EME Contest, which ran for 48 hours, on November 28 & 29, 2020, GMT hours. This time it was a cliff-hanger in that we almost didn’t get on the air. But with some dedicated effort we succeeded again. This time we contacted some new places. And we added JT65C digital mode.
Team members for this operation were Ray Uberecken AA0L, Gary Agranat WA2JQZ, Myron Babcock KL7YY, and Bill Miller KC0FHN. Floyd Glick WD0CUJ came out also for one evening, accompanied by our new member Michael Nameika.
For this weekend the Moon was at almost full phase. That meant that it would be up mostly during our nighttime, which therefore was when we would have to do our operations. The contest would start at 0000 Hours GMT, which for us was 5 PM on Friday evening November 27. The Moon was already rising at 3:19 PM, so it would be up high enough to begin operating right away, once the contest started.
Ray and Bill arrived Friday afternoon by 3 PM to set up and do last minute testing. I (Gary) arrived soon after.
In our testing, we found we could receive the 1296 MHz beacon Ray set up at his home in Peyton. But we couldn’t properly transmit.
We quickly slew the antenna to the service tower, and Ray retrieved the amplifier at the feed. The thinking was the problem might be there.
Ray did some quick testing of the amplifier. But an initial check didn’t find anything wrong.
Ray then climbed back up the tower to return the amplifier to the feed point. We thought about what else could be wrong.
We then checked how much power was being drawn by the amplifier in the pedestal. The power meter was reading about 30 Watts when we tried to transmit, when it should have been reading about 200 Watts. At that point the sky was getting dark. It would not have been safe to do any more climbing. And so for the first night of the contest we couldn’t operate.
Bill returned home, but was available the next day for coordination in Colorado Springs. Ray and I spent overnight at the site, to continue troubleshooting on Saturday. We would have the whole day in sunlight, until the Moon rose for the second pass at 3:47 PM.
Before going to sleep I (Gary) made some HF ham radio contacts. So we got on the air still, but on HF. This weekend there was also another contest, the CQ World Wide CW (Morse Code) Contest. On 160 and 80 meters I made three contacts with Canadian stations. There were lots of US stations on, but for the rules of this contest, you have to contact stations outside of your country (or more precisely outside of your DX area, which for us is the CONUS). I afterwards made some HF FT8 digital contacts for the club, on 80 and 40 meters. On 40 meters we made our first DX contact with New Caledonia in the southwest Pacific, with station FK8HM. This was with our recently repaired vertical antenna, so this showed our vertical was working OK.
Early the next morning I made some more CW contacts for the contest, this time on 40 meters using the vertical, and on 15 meters, using both the vertical and Yagi antennas. On 40 meters, while it was still dark across the Pacific, stations in China, Hong Kong, and South Korea were heard, but I didn’t succeed in making contacts. I did succeed though in contacting two Japanese stations. Then on 15 meters, with daylight across the Atlantic, the band was wide open to Europe. For a few minutes while on the air, we made contacts with France, Spain, and Slovenia, and also one contact to the south with Brazil.
Ray and I had breakfast and resumed troubleshooting work at 9 AM. We retrieved the amplifier again, and this time did a much more thorough test. Ray found one diode was leaking current. But this was a circuit safety issue and not a showstopper for transmitting. Ray replaced the diode, and returned the amplifier to the feed.
We then considered what else could cause our problem. Ray tested the conductivity of our feed lines. We have two coax cables running from the operations trailer to the feed. Ray climbed to the feed, and connected the two cables there. Then we measured the conductivity going out and coming back, together at the same time. His software analyzer showed Coax cable #1 had a fault at 135 feet down the line, and Coax cable #2 had a fault 185 feet down the line. This corresponded with where there are swivel joints for the cables, where the fixed pedestal interfaces with the moving dish antenna structure. A signal test also showed there was more loss on the lines then expected.
At first Ray wondered that the swivel joints might be the problem. However, on visual inspection those were seen to be OK. The problem was eventually traced instead to the weight of the cables at that location pulling on the centers of the feeds, causing those to slip out.
Ray was able to repair Feed Line #1. We then did more testing, with Ray’s beacon and the W0TTT beacon in Como, CO, and with an SSB tropospheric scatter contact with Myron in the Springs, and found we were working well. We were back in business.
Myron drove out to the site, and operated with us the second night. While Myron was on his way, I slew the antenna for Moonrise, getting more practice with the System 1 automatic tracking.
As soon as the Moon rose we heard CW and digital signals. We again had to figure out the Doppler shift correction, using the WSJT 10 software. At the start we made several CW contacts with Europe: to Germany, England, Croatia, France, Poland, and Austria.
Eventually we also tried digital JT65C –for the first time. That was a learning curve, but we finally got it. One of the tricks for that was that the waterfall window on the JT65C has a bar at top designating where the sync pulse of the signal has to be, in order for the software to decode it. Another challenge was that operators were heard with JT65 weren’t using a consistent contact exchange format. And so I had to manually edit the exchange fields quickly, in the 10 seconds between decoding and transmitting.
We made 19 contacts altogether. 16 were with CW (Morse Code) and 3 were digital JT65C. Myron tried several times to make SSB contacts. But there were no takers to respond back to us.
Over the night, I generally made the CW and digital contacts, while Ray operated the radio, including keeping up with the Doppler shift offsets. I offered to let others make contacts too. But we were comfortable doing it this way.
Floyd came during the evening with his astronomy student Michael Namieka. Floyd showed Michael around the site, and I believe also made some HF contacts in the bunker. They watched our EME operation. They got into a good technical discussion about the component causes of the Doppler shifts. Myron had Michael send a voice CQ and test moon bounce signal, and Michael heard his voice come back about 2 seconds later.
Our CW contacts included our DSES member Skip, VE6BGT — he said we sounded much stronger this time. And we found several other stations we had contacted last month too.
On JT65 we had QSOs with AL Katz K2UYH, W6YX Stanford University, and AA4MD in Florida (who last month we got on CW).
New countries to Europe this time were France and Croatia. We got KL6M in Alaska, who built our feed. We got one Japanese contact JH1KRC, who we contacted last month. And this time we had one contact with Australia, VK5MC, probably our contact furthest away from us. I am happy to report we had pileups on us. At least some of our contacts already knew something about us and our capability.
This is a record of our contacts, from the Cabrillo formatted file we submitted to the ARRL for the contest. CW is Morse Code. DG is JT65C digital. 1.2 G is the 1.2 GHz frequency band. You see the date and times in GMT, our station with the signal report we sent, and the station we contacted with their signal report to us. QSO: 1.2G CW 2020-11-28 2312 K0PRT 599 DG5CST 599 Germany QSO: 1.2G CW 2020-11-28 2317 K0PRT 559 SP7DCS 589 Poland QSO: 1.2G CW 2020-11-28 2324 K0PRT 559 G4CCH 599 England QSO: 1.2G CW 2020-11-29 0007 K0PRT 559 9A5AA 579 Croatia QSO: 1.2G CW 2020-11-29 0020 K0PRT 569 DL6SH 579 Germany QSO: 1.2G CW 2020-11-29 0040 K0PRT 569 VE6BGT 589 Canada QSO: 1.2G CW 2020-11-29 0057 K0PRT 579 OE5JFL 579 Austria QSO: 1.2G CW 2020-11-29 0216 K0PRT 569 WA9FWD 579 Wisconsin, USA QSO: 1.2G CW 2020-11-29 0350 K0PRT 559 F2CT 569 France QSO: 1.2G CW 2020-11-29 0403 K0PRT 559 KL6M 579 Anchorage, Alaska, USA QSO: 1.2G CW 2020-11-29 0407 K0PRT 559 OK1KIR 569 Czech Republic QSO: 1.2G CW 2020-11-29 0413 K0PRT 559 I5MPK 599 Italy QSO: 1.2G CW 2020-11-29 0420 K0PRT 559 K7CA 559 Nevada, USA QSO: 1.2G CW 2020-11-29 0430 K0PRT 549 KA1GT 559 Maine, USA QSO: 1.2G DG 2020-11-29 0629 K0PRT -06 K2UYH -01 New Jersey, USA QSO: 1.2G CW 2020-11-29 0750 K0PRT 569 JH1KRC 589 Japan QSO: 1.2G DG 2020-11-29 0811 K0PRT -08 W6YX -08 California, USA QSO: 1.2G CW 2020-11-29 0920 K0PRT 439 VK5MC 449 Australia QSO: 1.2G CW 2020-11-29 0946 K0PRT 599 N4PZ 599 Chicago, Illinois, USA QSO: 1.2G DG 2020-11-29 1006 K0PRT -09 AA4MD -07 Florida, USA
We decided to stop operating at around 3:30 AM Sunday morning. We were hearing much fewer new contacts. But also the outside wind was picking up immensely. Forecasts for the region were for gusts up to 50 knots. We stowed the antenna back to the safe position. Ray, Myron and I then got sleep in the operations trailer. Outside the temperature dropped to the low 20s, but we kept warm inside with the heaters. Myron left early in the morning. Ray and I closed the site by 11 AM Sunday, and headed back to the Springs.
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Some technical feedback: System 1 was working almost perfectly. The one glitch again was that there was a discontinuity in elevation reading on Friday night as the elevation was brought close to zero (seen by Bill). I didn’t experience that on Saturday or Sunday. Otherwise, the System 1 is an immense help. It makes the slewing and tracking easy and seamless.
We had a learning curve figuring out all of the nuances and details (or the sufficient and necessary details) for running JT65. We did eventually get JT65 working well. You do need to pay attention to its peculiarities. It probably could use some guidance documents, like we have for System 1.
I will note I did try to make a number of contacts but didn’t get responses. I don’t know why that was. I am suspecting part of the reason might be due to not getting the Doppler shift offsets quite right at times. But we did get a number of good signal reports and explicit comments that we had good signals.
Later I did some research. One of our contacts KA1GT has some articles on the Doppler shift math and corrections. These might be helpful:
It was a somewhat intense weekend for the team — with not being able to operate Friday evening as it got dark, with the troubleshooting, the cold and windy weather conditions and staying overnight (for some for 2 nights) on site. But we were very pleased we got our Moon communications back. We had lots of good signal reports. We apparently were doing better than in October with our signals. We probably had fewer contacts than last time as we were spending time figuring out the JT65 and Signallink. And I suspect there might have been fewer hams on for the second night. But I think also we didn’t want to knock ourselves out, especially with all the work we did. We found a good balance that worked.
I think all of us involved were very pleased with what we accomplished this weekend. We spent the effort to troubleshoot, we got ourselves back on the air, and we made a successful second EME Moon bounce operation.
2020-10-26 DSES Science Meeting Notes: by Bill Miller
We had 14 participants in the virtual science meeting today: Thanks everyone for joining.
Participants: Dr. Rich Russel, Ray Uberecken, Chad Carter N0ZMG, Don Lewis, Matt Mathews, Bob Haggart, Michael Nameika, Gary Agranat, Jonathan Ayers,Floyd Glick, Don Latham, Myron Babcock, Ted Cline on Phone, Bill Miller
Also see the Zoom Video Recording for more detail:
Problem with the 1296 MHz feed last weekend. Took down the Feed amplifier and found the unit was stuck in the transmit configuration due to a failed FET in the Relay driver. Fixed this and added a gate protection resistor to solve the problem.
A second issue was discovered with one of the coaxial swivel joints that failed on the feed lines. Will find a new swivel joint or alternate method of coupling the coax while allowing for the cable wrap.
See slide 4 of Rich’s slide presentation above.
Gary EME report.
See report of contacts in slide 5 of Rich’s Power point presentation above.
On November 28 and 29th there will be another EME contest under nearly a full moon.
Nov 27 – 28 Moon Rise 3:19 PM set at 5:03 AM
Nov 28 – Nov 29th Moon rise 3:47 PM to about 6:03 AM
We will benefit by organizing the operation trip, to utilize our time while the moon is overhead with multiple operators.
Morse code is simple and effective. Can be done with the computer keyboard or with a keyer.
Simple protocol of multiple repeats on Call sign, signal report and acknowledgement should be followed.
Signals experience polarization rotation, we therefore circularly polarize our signal.
Operation on JT65C will be added.
Operating EME is an experience you won’t forget
Astronomy at Hydrogen Line 1420.406 MHz: See Rich’s PPT presentation page 6 to end.
SARA “Radio Astronomy in a Box” costs about $250 and is a great platform for a science fair project. Rich has one for evaluation and will lend to a worthy student.
2.4 G dish
Stellarium planetarium software
Can be used for science fair
Don’t download the SW, as it has a virus.
Rich has another source of virus free SW.
We have a new student member, Michael Nameika who is a student at UCCS interested in Astrophysics and Radio Astronomy. He has been working with Professor Floyd Glick at the PPCC observatory and with Steve Plock. Welcome, Michael.
Myron Babcock, DSES Treasurer, has received a very generous donation of a Yaesu FT-736R from N6KN, Rocco Lardiere in California. He also triple boxed the unit and paid the FedEx postage to ensure that it arrived in great shape. This will make an excellent addition to our radio resources and backup to our high band EME and Tropo communication. Thank you, Rocco.
By Gary Agranat, with Myron Babcock and Glenn Davis. Videos by Bill Miller.
On Saturday October 10, 2020 we succeeded in making our first Earth-Moon-Earth (EME) Moon Bounce communications. We succeeded at our first attempt. This accomplishment was several years in the making, thanks to the work of many members, past and present.
We did this participating in the annual ARRL EME contest held on the weekend of October 10-11, 2020 GMT. (That’s Friday 6 pm to Sunday 6 pm local time.) The frequencies available for this contest were in the ham radio bands from 50 to 1296 MHz. We used our 60-foot dish antenna at Haswell, CO, with a 1296 MHz feed with dual circular polarization, installed 2 weekends earlier.
EME Moon Bounce communications is directing a signal to the Moon. The Moon’s surface simply reflects the signal back to Earth. If the Moon is above your horizon, if you have suitable equipment, and if you know enough about what to do, it would be possible for you to receive the signal and communicate back. You could communicate to your neighbor or across continents. The signals, however, are extremely weak, having to travel back and forth the Earth-Moon distance, over 238,000 miles. EME generally requires efficient directional antennas to sufficiently increase the signal gain. Amplifiers can be used too. And the antennas have to point to the Moon. Also, radio signals sent through the ionosphere experience a rotation in their polarization. And there is some effective rotation from other causes, including from the changes in orientation from the Moon and from operating on different points of the Earth’s globe. Our solution is to circularly polarize our signals. And also, there is a Doppler shift between transmitted and received signal, mostly due to the Earth’s rotation, causing a difference in velocity between the Moon and our location on Earth. All of these are challenges to deal with.
Our team for the EME operation were Ray Uberecken AA0L, Myron Babcock KL7YY, Gary Agranat WA2JQZ, and Glenn Davis. Bill Miller KC0FHN also came on Saturday morning.
The team arrived Friday evening October 9, while we still had daylight, to set up and test. Testing included making pre-arranged tropospheric scatter contacts, which were successful. We also attempted to complete set-up of a Hughes Internet antenna, to give us Internet access, but that was not successful. We instead sometimes connected to the Internet using cellphones. Although the contest began at 6 PM local time, we had to wait for the moon to rise above the horizon. Moonrise for us was at about 11:30 PM local time, and the Moon was above our horizon until about 2 PM local time the next day Saturday. We chose to stay for just this one Moon pass, and not continue through Sunday, in order to not knock ourselves out on this first attempt.
After we completed our testing, we relaxed until we were ready to start. Looking outside, we had an exceptionally deep starry sky. We could see the Milky Way clearly arching overhead through Cygnus. Jupiter and Saturn were bright to the south, and Mars was very bright, rising in the east. Glenn Davis experimented with his camera and took some nice time exposure photos with the dish antenna, the stars, and the Milky Way.
I (Gary) meanwhile got some rest. This enabled the others to get some rest later in the morning while I continued.
Myron KL7YY wrote and emailed an update about our operations to the DSES membership on Saturday morning at around 4 AM. It provides a good narrative of how we were doing until that point, and his update follows next:
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Summary of DSES first attempt at EME, Earth Moon Earth, contacts using the 60 foot dish:
On Friday evening, October 9 we started with a few nearby Tropospheric Scatter contacts around 7 PM with DSES member KL7IZW, Steve in Monument, CO, and W6OAL Dave in Parker. Around 9 PM we talked to N0YK in Scott City KS, These contacts ranged from 110 to 130 miles and confirmed that our system was working.
When the moon came over the horizon at midnight we tried to listen to the ON0EME moon beacon in Belgium but couldn’t hear it. About 45 minutes after moon rise we started to hear JT-65 digital signals. 10-15 minutes we started to hear CW signals. Glenn Davis made a few corrections to the tracking program and signals increased in strength. At times it sounded like a 20 meter CW contest pileup with all the loud signals bouncing off the moon all across 100 KHz of band (1296.0 to 1296.1 MHz). After about 90 minutes without hearing our own signal we rechecked the power to the amplifier at the feed horn and everything appeared to be normal. A few moments later we finally heard our own signal 2.5 seconds later on CW off the moon and the Belgium Moon Beacon. I made several calls on SSB and heard our echo really loud. We went back to CW and Gary proceeded to start making CW contacts. The first almost contact, a German station, abruptly dropped out so no official contact was completed. Our first official station worked on CW was with OH2DG in Finland. England was next followed by Italy, Poland, Denmark, Sweden and with DSES member Skip Macaulay, VE6BGT, in Alberta Canada.. Also made our first voice SSB contact with him as well. Seems that with every new contact we make it is with a new European country. In order to correct for Doppler shift and with no RIT we are changing VFO’s from Receive to Transmit by several KHz or more. Lots of CW signals being heard and we still have 12 more hours of moon to bounce signals off of… We are hearing our own echo and we have lots of hours to go. We plan on Digital mode later in the day but for now there are more than enough signals to hear on CW.
Our Moon bounce station consist of an older Yaesu FT-736R with 10 watts feeding almost 180 feet of half inch hardline into a 200 watt amplifier at the antenna feed horn. The receiver pre amplifier is a 30+db gain with a noise figure of minus .35. Our Effective Radiated Power (ERP) is over 6 million watts.
* * * * * * * * * * *
We operated with our club call sign K0PRT.
A short video of Myron KL7YY calling CQ. You can hear the echo of his signal coming back from the Moon a couple of seconds later. (Video length 35 seconds)
Because the signals are extremely weak, and there can be fading, there is a standard protocol for exchanging messages for EME contacts. This is intended to ensure as much of the message as possible can be copied and acknowledged on both sides. The basic format is simple, and one repeats a lot. One first exchanges call signs, then the signal reports, and then finally if that worked, an acknowledgement all that was copied correctly. If one only completes part of the contact, one should still log that, as that is an accomplishment. If using Morse Code, the standard is to send at 15 words per minute, but spacing out the characters longer than usual. The faster sending and spacing is to help one copy complete characters if there is fading. If one misses a character, one still has a high chance to get the character with the many repeats.
In order to have the proper frequency offset for the Doppler shift, we referenced the WSJT 10.0 software, at the suggestion of Steve KL7IZW. The software has an astronomical data section that calculates and displays the frequency offset. The higher the frequency, the more significant the offset. At 1296 MHz we had a difference of as much as 3 KHz between transmit and receive frequencies. The software also displays other useful data like local Moon rise and set times (based on Grid Square location).
The WSJT 10.0 software also can be used for JT65C digital EME communication. However, we didn’t figure out how to configure that in time with our setup, and so we didn’t do any digital contacts this time. We could tell we were hearing JT65 signals. They were present from 1296.05 to 1296.1 MHz, and we almost always could hear those signals while the Moon was up.
Glenn stayed up until about 3 AM, when we were sure our antenna azimuth alignment was correct and would continue to point accurately to the Moon. His work was invaluable in troubleshooting the azimuth offset, which turned out to be about 1.5 degrees, and honing in on the Moon once we heard CW signals.
Since the Moon rises in the east, our signal paths at first are to the east. That is to Europe and the North American east coast. As Myron mentions, once we started receiving the signals, we were hearing many European stations, and we were busy. Through the morning we made 14 contacts to Europe, to 8 European countries. We also made the contact to our DSES member Skip Macaulay VE6BGT in Alberta, Canada, on CW and then phone. W4OP in North Carolina, hearing us on SSB, then gave us a call on SSB too.
Ray AAOL brought a CW keyer that can send Morse Code with either a keyer paddle or a keyboard. It can store pre-programmed messages, like a CQ call. I (Gary) decided to use the keyer paddle, as that gave me more flexibility — I could quickly adjust for conditions — and I felt more comfortable as I am used to the key. Meanwhile, it seemed to me also that some of the CW contacts we made used software to send their messages. Those didn’t have good spacing between words or call signs. And that made copying slightly more challenging. A keyboard though can enable any of us to send, even if we don’t have practice sending Morse Code. Most of the contacts we made were with CW Morse Code.
This short video shows part of a Morse Code CW contact by Gary WA2JQZ. XE1XA in Mexico called CQ. We responded by sending our call sign K0PRT several times. Then K (the invitation to respond) several times. When we switch the VFO from the transmit to the receive frequency, you can hear the last part of our signal coming back, reflecting from the Moon, several seconds later. You then here the signal from XE1XA, also coming back reflecting from the Moon. He transmitted back our call sign as K0PRN, instead of K0PRT. We afterwards replied sending our callsign again, only, to give him the correction. That’s why we repeat a lot, and send sections of the message just one at a time. We completed the contact successfully. If you look carefully on the transceiver, you will see we switched about 2 KHz down from the transmit to receive frequency. (Video length 1:16)
At around 6 AM, when the Moon was high enough so that we no longer had a path to Europe, we took a break for breakfast and to rest.
In earlier discussions we thought we might have many more contacts across the Pacific and to the North American west coast, when the Moon was sufficiently to the west. But it turned out we had very few contacts that way. We made just two contacts to Japan. Our first was at about 9 AM local time, to JH1KRC. Our second was three hours later to JA6AHB. Instead we made a few more contacts to the US, a few to Canada, and one to Mexico. These other stations we heard were searching around too. That led me to believe that if there were any other signals out there, we likely would have heard them.
W5LUA Albert Ward in TX, who some in our group know for EME. (He at first thought I was Ray, when I contacted him on CW. Myron then contacted him on SSB.)
W6YX, the Stanford University radio club, which was using a 28 foot dish. We contacted them first on CW. Then later when Bill was looking to record a phone QSO, which would illustrate the signal delay from the transit time to the Moon and back, W6YX just happened to call CQ on SSB on the frequency we were tuned to. We then had about a 4 minute QSO on SSB with them, which Bill recorded.
A video of Gary WA2JQZ responding to W6YX at Stanford University and having a 4 minute SSB QSO. (Video length 4:38)
We operated until about noon. We made 30 contacts in all. 25 contacts were CW (Morse Code) and 5 were SSB phone. 4 of the 5 phone contacts were with stations we also had CW QSOs with.
We submitted our contest log to ARRL the next day.
In the judgement of all of us, we had a very good EME operation. We are very pleased it worked so well on the first attempt. We clearly have a capable EME station.
Glenn and his team are continuing to follow up to investigate why we had a 1.5 degree azimuth offset.
It still takes my breath away to hear the echo of our signal coming back from the Moon, a couple of seconds later. The speed of light isn’t just a value in the books, it is something you experience viscerally first hand. It is real. EME is the longest signal path we have for communicating with others. This is fun.
These are the contacts we made. (CW = Morse Code, PH = SSB phone. Given also are the date and GMT times, the signal reports, and the other stations and their locations):
Total Contacts by State \ Province: AB 4, CA 2, TX 2, BC 1, FL 1, NC 1, NJ 1, WI 1. 8 total.
Total Contacts by Country: USA 8, Canada 5, Czech Republic 3, Federal Republic of Germany 3, Italy 2, Japan, 2, Austria 1, Denmark 1, England 1, Finland 1, Mexico 1, Poland 1, Sweden 1. Total countries 13.
Total Contacts by Continent: Europe 14, North America 14, Asia 2. Total continents 3.
A DSES team worked at the Plishner Radio Telescope site in Haswell on Sunday September 27, 2o2o. Team members were Ray Uberecken, Floyd Glick, and Gary Agranat. We accomplished the main objective, to install a new 1296 MHz feed at the focus of the 60 dish antenna. We also installed a mast in the ground, on which will later be added a Hughes Internet satellite antenna. Two friends of Ray’s came out and did an immense service by using metal detectors and magnetic rollers to clear nails and other metallic debris on the site. We changed out two of the locks. And we inspected the bunker.
Mast for Hughes Internet antenna
Ray and I met at the Plishner site at 0930 in the morning.
We first installed a sturdy pipe mast behind the operations trailer, on which will be mounted a small satellite antenna to access the Hughes network geosynchronous satellite for Internet access. Ray chose a spot that will not be blocked by the trailer or the 60-foot antenna. We mixed cement and set the pole in its hole with the cement, using a level to check that the mast is vertical.
Moon Bounce (EME) Preparation
After that we manually rotated the 60-foot dish antenna to the service platform. I figured out, with Ray’s help and the checklists, how to use the software to monitor the antenna pointing. (Note: we might want to add a checklist just for this type of procedure, for using the software for just manual antenna pointing, as when we service the antenna.)
Floyd came out to the site by 1030. Ray and Floyd climbed the service platform. I worked on the ground to move feeds and tools up and down to them. We replaced the 408 MHz feed at the antenna focus with the newly built 1296 MHz feed. The 1296 MHz feed was built by KL6M, to specifications provided by Steve Plock (KL7IZW). The feed mount at the dish focus was designed by Ray, to enable the feed to more easily rotate out and be changed.
Conditions were somewhat windy, with a cold front coming, but still manageable. By the afternoon the winds had picked up enough that we postponed any further work at the feed. Work that still needs completion is installation of a 200 Watt amplifier at the feed. Since we are planning to operate at 1296 MHz from the Operations Trailer, which has a long coax hard line path to the pedestal and antenna feed, we expect significant power loss from the long path. We therefore need to boost the power again at the feed. We plan to install the amplifier the next weekend. We then also intend to test our setup by trying tropospheric scatter communications to the north.
We are planning to use this configuration to operate EME (Earth Moon Earth) Moon Bounce communications. And specifically we plan to participate in the ARRL EME contests on October 10-11, 2020 and on November 28-29, 2020 (UTC).
We discussed our plans for the upcoming contest in 2 weekends. The Moon then will be at last quarter phase. What that means is that it will rise on Friday night a little before midnight (about 1130 PM), and set Saturday a little after 2 PM. That means we will prepare to do overnight and morning operations. After the Moon rises we will try to pick up the ON0EME beacon in Belgium. We can try to contact across the Atlantic Ocean. The US East Coast will be in night time conditions, and so we anticipate less contacts to there. Daytime conditions, when more hams would be awake, are more favorable for the US West Coast, and across the Pacific Ocean to Oceana, Asia, and Australia.
Note that the 60-foot antenna will be configured with the 1296 MHz feed through the end of November. This will be an opportunity to try using it for other 1296 MHz communications, including troposphere scatter.
Metal souring of the site
A friend of Ray’s who works at Planet Granite Ryan, and his brother, Rob, came out to the site also. They have ground metal detectors and magnets on rollers, and systematically paced across the site to pick up nails and other small metallic debris. They did pick up lots of nails, including along the roadway. They spent a few hours with us, and left after lunch. They did us a great service by helping remove a lot of this debris.
Combination Lock and Bunker Inspection
We attempted to open the combination locks at the gate, the bunker, and the generator shack. After still having difficulty, we replaced the locks at the gate and bunker, with the locks Myron Babcock obtained for us. These are similar model locks, and the combinations were kept the same.
We had a report that the bunker had been flooded by two successive rain storms in July. We opened and inspected the bunker. The bunker was dry, though the floor had more-than-normal dust and dirt, and some tiny debris was spread here and there. It will require a fresh cleanup before normal use. We saw no indication of mold from dampness.
Tumbleweeds were accumulated again at the ramp entrance.
We completed our activities by early afternoon, about 3 PM.
Text and photos by Gary Agranat. Analysis pdf by Rich Russel.
On Saturday September 12, 2020 an observing team of Rich Russel, Bob Haggart, Bill Miller, and Gary Agranat spent the day observing pulsars. This is the first observing session since we recalibrated the 60-foot antenna azimuth pointing the weekend before. The team observed 3 pulsars we had not seen before. Plus several other pulsars were attempted. The team spent the whole day at the site, from about 9 AM to 7 PM.
The pulsar signals are so faint that we cannot detect them directly. To observe them, we have to point to the correct celestial coordinates and then track that point as the Earth rotates. While we are pointed, our computer accumulates the signal data. We need at least a half hour continuously tracking the position. At this session some of our observing runs lasted 2 hours, for the fainter objects. At previous sessions we have tracked for as long as 4 hours.
After the observing track, we have our software process the data. The random background noise should cancel itself out. But the pulse signals should build up with time. If we have the correct timing interval of the pulses, and if everything else is working, the computer display will show the pulses, and several other parameters.
Pulsars are very unusual objects. These are what remain of massive stars (greater than 5 solar masses) after they use up all their fuel for nuclear burning. These more massive stars fuse heavier and heavier elements at their cores until they start to fuse iron from silicon. Unlike the fusion of other elements, iron requires energy to fuse, rather than produce energy. The sudden reduction of energy at the core drops the temperature and pressure there. The pressure at the core is no longer enough to counter the weight of the star’s material above it. Gravity is now the stronger force, and the material above collapses in on the center. The pressure and temperature at the core then becomes even higher, which starts new reactions that fuse the matter at the center to neutrons, and and which also generates neutrinos. The outer layers falling in at great speed bounces back out. The result is a supernova explosion. What remains is the neutron star at the center. It is extremely massive and compact. And like an ice skater rotating faster as the arms are brought in, the star’s rotation speeds up immensely. The star’s magnetic field also has become compressed and much more intense. Charged particles will rotate around the magnetic field lines, with very high energy. Whenever charged particles are forced to deviate their paths from a straight line they emit electromagnetic energy, like visible light and radio. At the neutron star’s poles, this energy is channeled out, with immense energy. Because the magnetic poles are generally not at the same spots as the rotational poles, the beam of this light and radio is spun around like a light house. If Earth happens to be in the path of such a beam, we detect that as a pulsar. So that’s what we’re observing. These neutron stars are hundreds and thousands of light years away.
Pulsars were first discovered by accident in 1967, by Jocelyn Bell (now Jocelyn Bell Burnell) who was then a graduate student at Cambridge University. Bob contributed a recent photograph of her, posed by some radio telescopes. We now proudly have that displayed on the wall above our computer displays.
Because the observing runs take a while, for this session we decided to try watching some videos. Bob brought a DVD player and a large monitor. Gary brought some educational videos, including one about the Crab Nebula and pulsars. Rich brought some movies.
On this work trip the team also inspected damage to our ham radio antennas, damage probably from the storm weather over the past months. 7 radials at the base of the vertical antenna were damaged. And the 3 element Yagi antenna on tower was slightly tilted along its longitudinal boom.
Tumbleweeds also had accumulated again at the bunker ramp. Some of the surrounding fence had also been damaged from the weather. Rich Russel brought some fencing to use in the future, to place over the immediate entrance path to the bunker door.
Repair of the ham antennas and ramp clearing will be planned for a future work trip.
Nominally the Eastern Conference is held each year at the Green Bank Observatory in West Virginia. This year the conference was carried completely online using Zoom. The coordinator for this conference was our own DSES Science Lead, Richard Russel. Over 93 SARA members participated, including several DSES members. DSES members Ray Uberecken, Skip Crilly, and Rich Russel gave talk presentations. Rich also was elected as Vice President of SARA.