These are some photos I took of the DSES radio telescope site about a year and a half ago, in July 2016.
The altitude of the aircraft was 7500 feet above sea level. The elevation of the site is about 4500 feet, and so these photos are about 3000 feet above the ground. The radio telescope site is located in Kiowa County. The neighbors are ranches and farms.
Visible from the air, to the southwest of the radio telescope site, are the remains of a World War II training airfield. The pattern of runways forms a triangle.
Location and Time: On Sunday, Oct 29th Ed Johnson and Bill Miller made a trip to the site to reinstall and tune the computer for the System 2 dish controller.
Attendance: Ed Johnson, Bill Miller
Site Activities: A. Bill arrived on site by 9:00am, unlocked the facilities and fired up the generator. Ed arrived a little later and brought in the bench computer on which he had repaired the operating system corrupted by a MS update from the last trip. We immediately hooked up the computer to the controller interface in the pedestal control deck via the Ethernet LAN interface and got to work. Several items in the software needed to be corrected.
B. Ed added a Start and Stop ramp subroutine to the motor drive software to prevent the system from abruptly starting and stopping the drive at high speed. This generates a stepping ramp function to start the motors slowly and speed up to the desired speed and then slow down in a similar fashion to stop. It greatly helps to reduce the stress on the system and should reduce over currents from popping the 3 Amp breakers on the drives. Some amount of iterative tuning of this was needed to get this to work just right.
C. A problem was seen when the computer would pause and stop communicating with the interface about every 10 seconds. This is a critical fault which would render any closed loop control unstable or ineffective. We attempted to find the source of this problem. We traced and substituted the LAN switches, CAT5 wires and connections and eliminated this as a cause. We turned off as many processes in the machine that could interrupt the system as possible. Ed found that by unloading the MS Visual Studio program that the interrupts occurred about half as frequently but they still occurred. We finally concluded that the PC was just not fast enough to perform the control function with all of the other MS programs and housekeeping functions and this was causing it to hesitate. Ed decided to donate another laptop he has with considerably more speed for this function and will ready that for the next trip. Bill will pick it up at Ed’s in Limon if Ed can’t make the trip. In the mean time we left the bench computer in place to control the dish pointing.
D. While Ed was modifying the software and testing the movement, Bill monitored the result from the pedestal control deck and also spent some time mapping out about half of the controller box. He will finish that on the next trip and transfer the diagrams to schematic capture for documentation.
Observations: Some important observations are as follows: A. It was found that there is a fault in the elevation optical encoder. At several particular positions of the elevation the encoder would jump a number of degrees in value. For instance at 44 deg of elevation it would suddenly jump to 50 deg. So the 6th significant bit appeared to be faulty. These errors always occurred at the same positions indicating a fault in the encoder and not the electronics attached. This could be contamination or a scratch on the optical device. Since we use only half of the encoder for the +0 to 180 elevation position sensing it might be possible to realign the encoder 180 deg off and use the other half of the bits if no errors are seen there. If not the encoder will have to be repaired or replaced. This problem was not seen on the Azimuth encoder but we were not looking for it. A means of testing the encoders for such a defect would be a handy utility in the software that we should add.
B. Even with the start/stop ramp function and driving the dish at a relatively slow speed we still had the 3 amp breakers tripping, sometimes in the middle of a continuous movement when we were not starting or stopping. We need to measure the currents in these breakers and determine the root cause whether an overload, controller fault, worn or miss-sized breakers. This is a real nuisance when trying to move the dish and must be corrected before computer control can be effective.
C. Bill stayed in the tower communicating with Ed on the radio to position the dish from the previous ~ 45 deg elevation for 40 Eridani observation to the parked 90deg (birdbath) and 315 deg azimuth position. This 315 deg azimuth position is the optimum service setting to allow access to the upper deck and dish though the service portal. It is also the best position to allow the feed point to be driven in elevation only to the -0 or 180 deg position to place the feed on the service tower.
We had to wrap up the work by about 3pm to travel to other commitments. After setting the dish to the parked position Bill shut down the lights, locked all of the doors, returned the keys and shut down the generator using the original procedure of turning off the main gas valve. This may not be required anymore but as yet we haven’t officially changed the procedure and it is the safest condition if we are not on site for a while.
That concludes the minutes from our Plishner site work trip of October 29th, 2017
73, and keep looking up!
Snail Mail to our new Colorado Springs Address at:
Deep Space Exploration Society
4164 Austin Bluffs Pkwy. #562
Colorado Springs, CO 80918-2928
During the work trip on October 21, 2017, a single-band 1420 MHz circular polarized feed was installed. This feed was built by Steve PlockKL7IZW.
The antenna was set with an azimuth of 149.6° , and with an elevation 39.2° above the horizon. This allows the antenna to drift scan the sky along an arc, as the Earth rotates, at Declination -7.5° (celestial latitude).
This scan was designed to pass across the triple star system 40 Eridani, at about 0200 local time. This was a joint SETI project with Skip Crilly to make simultaneous measurements together with the Green Bank Observatory 40 foot radio telescope in West Virginia. The two sites are at about the same latitude, at a distance of about 1300 miles. Joint observations were scheduled for the early mornings of October 26, and October 29.
The specific target of interest was 40 Eridani A, which is at a distance of 16.4 light years. Eridani A has a habitable zone around it for an orbit calculated to take 223. The frequency spectrum of 1405 to 1445 MHz is continually sampled, in order to look for “triplets” signals. Simultaneous observing from two distant sites would rule out that any signals detected at both sites cannot be from local terrestrial sources.
The technique of “Drift Scan” is just keeping the antenna pointed in one fixed direction, while the sky passes overhead as the Earth turns. Rather than track a particular object, the sky is passively scanned, as the sky “drifts” across.
Total power measurement @ 1428 MHz, beam size 2°
Neutral hydrogen spectral line measurement
Also on this trip, Gary Agranat WA2JQZ operated the ham station from the bunker, to participate in the annual Boy Scouts of America Jamboree On The Air (JOTA). Ops were on 20 meters, using the bunker’s 160 meter dipole. Two JOTA stations were contacted in California, W1AW/6 and N6B. Other JOTA stations around the US and also Mexico were heard, but conversations among them were already well in progress, and so we didn’t interfere with those. Attempts were made to listen for the JOTA station in Colorado Springs, operated by Dave Molter AD0QD, but it was not heard. In between JOTA ops, the club also participated in the New York State QSO Party, on CW and SSB, with 19 contacts. And 9 contacts were made with JT65. The longest distance JT65 contact was to Spain EC2ATM, and with SSB to 9A3XV in Croatia.
Skip Crilly used his antenna analyzer to check both the 160 and 80 meter dipoles located at the bunker. He verified that most of the lower part of the 20 meter band was usable, and the 17 meter band was as well, but many of the other ham bands were not with the current length of the antenna. Ed Corn KC0TBE later also used his antenna analyzer to check the antennas and feeds. And he checked the amplifier.
Ed Corn also placed the two sump pumps on separate power inverter feeds. That ensured that each pump can start independently if both are needed simultaneously.
Paul Berge, who was active several years ago, drove to the site from the Denver area. He discussed past and current projects with the team. Paul Berge, Steve Plock, and Skip Crilly stayed at Haswell overnight, to continue work the next day. Overnight the sky was clear, with the Milky Way clearly visible. The Orionid Meteor Shower was in progress, and several other members of the team stayed past sunset to watch the night sky as well.
Also working at the site on this trip were Rich Russel ACoUB and Ed Schade KC0HCR.
The DSES Sudden Ionospheric Disturbance Monitor (SID) detected in September several major solar eruptions – M and X Class Flares. Below are shown graphs of the data from four particular days.
The DSES SID instrument is located in Colorado Springs. It works by listening for a US Navy beacon station in North Dakota, call sign NML, transmitting on the Very Low Frequency (VLF) of 25 KHz. During the day, the D Layer of the ionosphere forms at lower altitudes and attenuates the VLF signal. But during solar flares, VLF signals can more easily pass through the D Layer, and they then get bounced back to the ground from the higher F Layer. The more the solar flare activity affecting our ionosphere, the better the VLF signal from NML propagates to us.
Strong solar flare events show a characteristic spike, and then a “shark tail” as the ionosphere recovers.
At night, the D Layer dissipates, and then the signal from NML usually easily reaches the receiver. At local sunrise, at about 1200 UTC, you can see the effect of the D Layer forming with the sudden drop in reception.
You can see evidence that the F Layer is influenced by the solar flares as well. Notice during the X 8.2 Flare on September 10 that the incoming signal becomes even stronger than during normal propagation at night.
The bottom axis of each graph is Greenwich (UTC) Time. The vertical axis shows the received energy. Individual flare events are identified and annotated in green. Some events occurred during local night.
Last November (2016) we tried participating in our first contest. This was the annualARRL Sweepstakes for CW (Morse Code).
The goal of this contest is to contact hams across the U.S. and Canada. As such, it is usually a sociably friendly event. Your points do get multiplied for each ARRL geographical Section you contact. Some Sections are whole states or provinces, like Colorado is its own Section. Some populous states though have a few Sections within them, for example California. If you contact all the Sections in one contest, that is called a “Clean Sweep”, hence the name of the contest. That is a lot of work. For many hams, though, this is just for fun, and a chance to make contacts with other folks in other places. I was looking forward to having some fun making contacts from our site, and bringing our club call sign K0PRTon to the air.
To our surprise we just received a certificate from the ARRL that we wonFirst Placein our category for Colorado! Our category was Muli-Operator (for two or more hams operating) Low Power (less than 150 watts).
We actually only made 8 contacts for the contest: 6 on 20 meters and 2 on 15 meters, to 7 states. Then at that point we discovered our CW signal had a chirp. We were operating on battery power from the site. And when we drew current as we pushed down the telegraph key, the voltage dropped too much. Later we added a regulated power supply to our ham station to solve that problem. But on that day we decided we should just stop, as our signal sounded awful.
And yet, what we did was enough in our category to still earn First Place!
Sometimes there are not many stations operating in a contest as multi-operator low power. I investigated into the contest records, and that was the case this time. That said, I am still proud of what we did. Bringing together a team to operate and have fun is not necessarily easy. And we did this at our remote site. Our category has its challenges. Congratulations to our Club! We earned a First Place certificate. We will have more opportunities.
The following video and text were posted by Bill Miller, DSES Secretary. Click the link to watch the 7 minute video. Bill traveled to Lusk, Wyoming to watch the the recent total solar eclipse. – Gary WA2JQZ
In this video of the August 21, 2017 Great American Total Solar Eclipse, shot on Main Street in Lusk, Wyoming, I used a Canon EOS Rebel T3 DSLR in manual focus and automatic exposure with a 250mm f/6.3 lens mounted on a non tracking tripod and a low cost 3 inch Celestron solar film filter suspended on a makeshift mount in front of the lens. Most of the stills came in around 1/320 sec at ISO-1600 with the filter. This worked reasonably well for the gusting wind that buffeted the filter and camera.
The first part of the video is a sequence of the partial eclipse leading up to the totality with a frame shot manually every 1.5 minutes and the camera repositioned every 6 to 8 frames to show the progression and movement of the sun and moon across the sky. The same was done for the partial phase after the totality. The two small dots to the left of the partially eclipsed sun are not stars but dead pixels in the camera which I didn’t realize were there until now.
The camera was changed to movie mode leading into the totality phase and the background audio captures the comments and excitement, we and some of the people around us experienced. Shortly after the “diamond ring” appeared at the onset of totality the solar filter was swung out of the way and the camera automatically adjusted movie exposure settings for direct unfiltered viewing of the totality. During the totality, planets and stars were visible and the movie captured Mercury, (what I originally called out as Venus) just to the lower left of the eclipsed sun.
When the “diamond ring” reappeared the solar filter was swung back into place to protect the camera imager. After a few minutes of post totality commentary from the bystanders the camera was returned to still mode and the outgoing partial eclipse sequence was again recorded in stills. The pre and post partial eclipse still images were added to the totality movie to edit the complete video.
Lessons learned: This technique was simple and worked reasonably well while allowing us to concentrate on experiencing the eclipse without having to worry too much about the camera, but If I could do it again with much more practice and gear I would:
Use multiple cameras to capture the surrounding scene and darkness during the eclipse and a dedicated wide angle time-lapse camera for a wall framing shot.
Use a time-lapse Intervalometer to precisely time the partial eclipse still shot sequence and also help stabilize the camera without touching it.
Mount the camera on a tracking telescope mount set up for solar tracking so the sun stays centered in the frame for the entire 3 hour event.
Use a much sturdier tripod such as that of my telescope and seek a sheltered location out of the wind on the side of a building to improve camera stability and comfort for the 3 hour event.
Use a better solar filter or find a way to shield out ambient light leakage to the camera to reduce the aura or glare captured around the partial eclipsed sun, though some of this aura may have been due to smoke in the atmosphere from western wildfires.
I hope you enjoy this little 7 minute movie. Best Regards,
DSES President Dr. Richard Russel has been measuring signal strengths 0f stations in the Very Low Frequency (VLF) band for the past year, looking for changes in ionospheric propagation due to solar flares. He uses a Sudden Ionospheric Disturbance (SID) monitor small radio telescope. His SID detector is located in Colorado Springs, CO. The measurements are sensitive to the changes in radio propagation at sunrise and sunset.
With his baseline of historical data at sunrise and sunset, he then predicted what could be expected during the August 20, 2017 solar eclipse. He presented his prediction work at the 2017 Society of Amateur Radio Astronomers Annual Conference at NRAO Greenbank, WV on July 25, 2017. His paper was titled, “Ionospheric Reflection Variation During Sunrise and Sunset and Predictions for the 2017 Total Eclipse”.
During the eclipse he made measurements, and found the results matched closely with his predictions. The link presents a summary of his work. Plus it has YouTube links to this and another of his talks at the SARA conference. The second talk is titled, “The Use of Monte-Carlo Analysis to Evaluate Radio Astronomy Source Detection”.