Prepared for the Deep Space Exploration Society by Skip Crilly. Revised November 8, 2018.
This is an updated revision of Skip Crilly’s slide set, originally presented last summer. Skip points out that the revision includes a summary of the pulses of November 2017 through November 2018.. Two newer NRAO 5690 plots in the presentation show the very stable performance of the telescope, and the narrower Plishner beamwidth.
Bob Haggart N0CTV is working on building a new stairway and porch to the communications trailer at the radio telescope site. He started the work at home after taking measurements. Today he traveled to the site to continue the work. With him were his grandson Allen and Allen’s friend Ben. Bob writes:
“We arrived at 11 AM. Worked on the porch and covered the fan with 24″ X 24″ plywood. Ran out of time but did get the porch assembled and painted inside and out. The hand railing is only temporary and will finish next work day on the 17th.”
Bob’s work is replacing a small simple set of metal steps that has given us access to the communications trailer.
The new porch and stairway provide a great improvement.
Thanks to Bob for all this work, and for improving the access to the communications trailer.
This is a summary of our activities at the Plishner radio telescope site during the third week of October 2018. Steve Plock, Ed Corn, and Gary Agranat contributed to this report.
Participants this weekend were Gary Agranat, Paul Berge, Tony Bigbee, Ed Corn, Hans Gaensbauer, Dave Molter, Steve Plock, and Rich Russel.
Our plan for the rest of the year is to work at the site during the third weekend of each month. The Friday evening is devoted to astronomical observing, and the rest of the weekend is then devoted primarily to infrastructure and equipment work.
60-foot Antenna Observing, by Gary Agranat, WA2JQZ
On Friday afternoon and evening Rich, Gary, and Paul did 1420 MHz neutral hydrogen observing with the 60-foot antenna. The primary observing goal was to take regular measurements of the hydrogen signal along the Milky Way galactic plane at 10 degree intervals, from the galactic center to about 110 degrees (a little more than the first quadrant). The Doppler shift of the hydrogen was measured at each 10 degree point. From that, Rich later used some basic geometry to derive a velocity and distance from the galactic center for each measurement. A second goal was to observe several known, strong galactic radio sources that could be used in the future for calibration of our observations, and also to see if we are capable of observing those sources in a consistent way (without unknown biases). A third goal was to observe additional galactic sources as targets of opportunity, to see how well we do, and to also see what problems we hit.
Galactic plane observing started at about 5 pm local time, when the galactic center in Sagitarius had risen high enough in the sky for us to observe. The galactic plane and most of the other observing were done with the 60 foot antenna pointed along the meridian (180 degrees azimuth to the south and zero degrees to the north), in order to eliminate the Earth’s rotational motion in the Doppler shift measurements. We observed until about 10:30 pm, when the team was then quite tired. To warm us up during the evening, we made a batch of hot apple cider.
Details of the observations and results were discussed at the science meeting on Monday October 22nd, and those will be covered in a separate post.
– Gary WA2JQZ
We’ll continue with the discussion of the weekend infrastructure work.
Saturday Infrastructure Work by Ed Corn, KC0TBE
Our first order of business was to re-service the toilet and spare in the outhouse. They now both have RV antifreeze for winter. Next installed was a portable heater for winter operations and I labeled all the breakers in the out house. I then labeled the doors with instructions for emergency exit and the safety pin for privacy at the main door.
With the help of Gary, Hans, and Paul we have the first 3 tower sections in place at the bunker, along with the first set of guy wires. [More about the tower below.]
-73’s Ed KC0TBE
DSES Site Work Report by Steve Plock KL7IZW, DSES President
Paul Berge worked on Friday, Saturday and Sunday. Because he travels from Lyons, Co. he prefers to maximize his efforts each visit. Also the weather window for the year is closing. I attempt to support his efforts as best as I can. Paul provided support for Rich Russel’s data acquisition which included galactic Doppler measurements. The team knocked off before midnight. Results have already been detailed in the Science meeting on 22nd of October.
On Saturday Ed installed a heater in the outhouse, winterized the RV toilets, and labeled the outhouse breakers.
During Saturday afternoon Hans, Ed, Paul, Steve and Gary all worked together to erect the new communications tower. The first set of guys were finished at 23 ft. by Ed Corn doing all the climbing. The majority of the rest of Saturday myself and Paul spent evaluating the elevation limit switch operation, including testing complete functionality with fault clearing via the built in override capability.
Later that day, Tony Bigbee showed up, and Paul and Steve supported subsequent hydrogen observations using the RASDR4 receiver.
The majority of Sunday was consumed by lubrication of the dish and adjustment of the azimuth drive chain. I also installed the conduit in the elevation bulkhead so that Bill Miller can complete his synchro wiring project.
Sunday Dave Molter worked into the night using the 500W floodlights and mixed over 1000lbs of concrete to try to prevent continued erosion in the ramp area. A big thanks to all who participated in this cooperative effort.
Our DSES ham radio club station K0PRT participated in the 2018 Washington State QSO Party, called the “Salmon Run” on September 15. We received this nice certificate today for our participation. We made 26 contacts on the 20 and 40 meter bands from our station in the bunker, using the multi-band vertical antenna. 22 of the contacts were with Morse Code (CW), the other 4 were with SSB phone.
All of the US states have ham radio QSO parties at some time in the year, on particular weekends. The QSO parties give the hams in those states a chance to get on the air and meet the rest of us, and gives us a chance to meet them. Canada also has some QSO parties, and there are some around the rest of the world as well.
Participation in QSO Parties is one of the ways we as hams in DSES can connect with the ham radio community. On September 15, 2018 we also participated in the Iowa and New Jersey QSO Parties, which were running that weekend. From what our contacts in New Jersey told us, we seemed to be one of the few stations from Colorado reaching or trying to contact New Jersey.
These are the slides from Dr. Richard Russel’s presentation about the radio astronomy observations conducted at the Plishner site during the previous Saturday, September 22. The observing period was chosen for Saturday afternoon, when the Milky Way around the galactic center was starting to rise high enough in the east. Observations were done using the Spectracyber at the 1420 MHZ neutral hydrogen I (HI) frequency.
Goals for the observing included 1) using our in-house Radio Astronomy Guide as an observing reference, 2) seeking strong enough sources listed in our guide that could serve as calibration references, 3) scanning perpendicularly across the plane of the Milky Way to observe changes in hydrogen signal while pointed inside and outside the galactic plane, 4) starting a series of doppler shift measurements along the plane of the Milky Way at galactic longitudes 10 degrees apart.
Some sources were found, but some were not. Among those found were Centarus A, Sagitarius A, and Virgo A. A number of peaks in the hydrogen signal were seen where we didn’t have any reference information that sources were present. The scan perpendicularly across the galactic plane showed the higher concentration of hydrogen in the galactic plane. We likely also detected the weaker signal of hydrogen known to be above and below the plane in certain regions. For this observing set, some sources like Sag-A were so strong that they oversaturated the voltage scale we had initially set. Doppler shifts were measured at 5 points, 10 degrees apart, along the galactic plane. Please see the slides for details.
Please click the link to see the power point slide show.
Please read our Review of our annual Open House at the Plishner Radio Telescope site in Haswell, in August 2018. We host our Open House each year during the Perseid Meteor Shower. The link will open our review report as a PDF file. It was an enjoyable weekend, with many science and social activities. A significant highlight is our ability to now make observations with the 60-foot antenna. With many photos.
Participants: Steve Plock, Ed Corn, Rich Russel, Dave Molter, Gary Agranat.
Summary and photos by Gary Agranat.
We worked at the Plishner Radio Telescope site on Saturday August 25, 2018. One motivation was to proceed with needed infrastructure work before the cold of winter returns. Another motivation was to follow up on the observations we made during the Open House with the 60-foot antenna. In addition, the antenna tuner for the bunker ham radio station was still not running, and needed to be checked. Here is a summary of what we did, with some photos.
1. Ed and Steve replaced the outflow hose from the ramp sump with one more durable (including durable against mice). Ed tested that the outflow did drain away from the ramp area. We placed a new aluminum manhole cover on the sump access (vs the original steel one), fabricated by Steve.
2. Ed moved the Internet hotspot to the bunker. The hotspot was used by Gary while testing and operating the ham radio station.
3. Dave brought 20 x 60-pound bags of cement, and used all of them to continue to repair/rebuild the ramp retaining wall. He made considerable progress extending the base of the wall. The higher the base of the wall reaches up the ramp, the less rain sediment will clog the sump pump. Dave stayed until late in the evening, until around sunset. Gary stayed with him and gave some help.
4. Rich brought the SpectraCyber 1420 MHz Hydrogen Line Spectrometer, and used it to continue to test the functioning and ability of the SpectraCyber together with the System 1 pointing system on the 60-foot antenna. Rich later showed Gary how to steer the dish antenna, and how to measure and record neutral hydrogen data. By the end of the day we located and measured several radio sources in the Sagitarius region. And we made a systematic scan almost perpendicular to the Milky Way galactic plane, in order to measure neutral hydrogen while pointing away from and in the plane. A more detailed discussion follows later in this post.
5. Gary tested the setup of the newly installed auto tuner for the FT-897 in the bunker ham station. With some adjusting and checking of cable connections, the tuner was found to be functioning OK. Gary took the opportunity to operate K0PRT in the QSO Parties this weekend for Kansas, Ohio, Hawaii, and for the US & Canadian islands, making about 30 contacts, on SSB and CW, on 40, 20, and 15 meters. Signal reports were mostly good, which seemed to indicate the combined FT-897 + tuner system is working OK. Gary wrote some Guidance Notes for using the tuner, and left those next to the tuner.
6. We received 20 QSL cards in the mail from the Open House special event station. Myron passed them on through Ed to Gary. Gary responded to all of them, and sent in the mail our QSL card responses to all by Monday.
Next are some photos of our work. Then follows a more detailed discussion about the SpectraCyber observations with the 60-foot antenna.
SpectraCyber observations with the 60-foot antenna
Rich brought the SpectraCyber 1420 MHz Hydrogen Line Spectrometer, to follow up on the successful observations we started to make with the 60-foot antenna during our Open House 2 weeks before. We used the System 1 pointing system. I later joined him by mid afternoon, after I finished my other work, and this is a report of what we did.
We started by searching for several sources with flux density values higher than 200 Janskies. However, at first no sources were found. The plane of the Milky Way was at that time very low along the southern horizon. There were few strong sources on our list available to look for at that time.
A little later, we just about ran into the Milky Way without looking for it, when the galactic plane rose higher. The signal trace of the SpectraCyber indicated the change: pointed away from the galactic plane, the signal trace stayed near about 3 volts, varying probably with noise, but not by more than a volt. Once pointing at the galactic plane, the voltage trace increased from about 5 to 7 volts (up to about 4 volts above the noise floor). The signal consistently showed a peak at about the center of the trace, at about the frequency of neutral hydrogen. We have not calibrated the SpectraCyber, and so we don’t exactly what frequency we were peaking. (The actual spectral line frequency is 1420.40575 MHz. And we may be seeing some doppler shift in our measurement.)
We then looked for several strong sources in the Sagitarius region, which by then had risen. We successfully found several, including:
Sagitarius A, the center of our Milky Way galaxy. The radio emission is thought to be from the secondary effects of a black hole there.
CTB 37, a supernova remnant about 20,000 light years away (see https://www.nasa.gov/mission_pages/chandra/ctb-37a.html.) Our signal trace showed three peaks through most of our scans. Our interpretation is that the central peak is the original supernova remnant. The other peaks would be the doppler-shifted material outflowing away and towards us, following the supernova explosion.
The Sagitarius Star Cloud Messier 24, with a colder hydrogen cloud closer along the line of sight that absorbs some of the M24 hydrogen signal. This is the radio source Tony Bigbee pointed to during our Open House 2 weeks earlier. The signal trace has a distinctive dip, which had been identified in data from the Parkes Observatory in Australia. And as Tony has discussed, was used in the past by the RASDR2 team as an engineering detection test. The dip in signal is interpreted as a hydrogen cloud along the line of sight that is colder than the background source. It absorbs the background signal and then reradiates it out, but in all directions, hence the net signal to us is reduced. We used the RA & Dec location coordinates recorded during the Open House. We found the source again without difficulty.
We used the System 1 computer display to read the angles our 60-foot antenna was pointed to. The display showed coordinates in both azimuth & elevation (Earth ground reference), and Right Ascension & Declination (celestial sky coordinate reference). We turned the antenna with the manual steering controls. At this time we do not have automatic tracking ability. But we were able to reasonably stay on our targets with continual manual adjustments. What we more often did was we found our source, then allowed the antenna to scan at the set elevation as the Earth rotated, and as a result get a short scan along a line of Declination. We then moved the elevation up and down slightly, to see differences in the scans a little north and south. We used this technique also to hone in on targets.
We then manually scanned across the Milky Way galactic plane, to obtain a slice from 16 to 20 hours Right Ascension, along the declination of -05 degrees. We stopped at intervals of 30 minutes Right Ascension (e.g., 17h 00 min, 17h 30 min, 18h 00 min, …), to let the SpectraCyber take full scans.
Our scan cut a steep acute angle through the width of the galactic plane, going across the constellations of Ophiuchus, the north edge of Scutum, and the southern part of Aquila. We therefore started and ended at angles pointed “above” and “below” from the galactic plane, and scanned across the galactic plane in between.
Since we were pointing to the southeast (and not due south), if we moved azimuth while maintaining elevation, the declination still changed. And so to keep on the -05 degree declination line, we had to adjust azimuth and elevation together.
DSES Science Meeting August 27, 2018 Follow Up
On the following Monday we had our monthly DSES Science Meeting at the home of Rich Russel.
At the meeting we discussed the observations we made with the 60-foot antenna two days earlier.
Tony Bigbee then also presented deeper details about his RASDR4 (Radio Astronomy Software Defined Radio). And he gave us more background about the earlier RASDR2 observations of Messier 24, with the dip in frequency. And he showed how he researched the earlier Parkes observatory data to find useable results and plots for us to compare to.
The following is a comparison of simultaneous observations made on August 15, 2018 of the astronomical radio source, NRAO 5690.
The first plot is an observation made by Skip Crilly at the 4o foot radio telescope at Greenbank Observatory in West Virginia. The second plot is an observation made by Steve Plock at the DSES Plishner 60-foot antenna in Haswell, Colorado.
NRAO 5690 is a catalogued supernova remnant (SNR), with the celestial coordinate location of 18 hours 35 minutes Right Ascension and -7 degrees 20 minutes Declination. It is known to have an apparent radio brightness of 90 Janskies at 1.4 GHz *(1).
Each observation was made by Drift Scan. Drift scan is fixing the azimuth (left-right) direction of the antenna, and scanning the sky as the Earth rotates. For each dish antenna, the elevation above the horizon is also fixed. As the Earth turns (at a quarter of a degree per minute), each antenna can detect radio source objects within its sensitivity, as the objects cross the beam width.
The observation at Haswell was done during a 42 hour drift scan at -7.6 degrees declination, in support of the joint SETI (Search for Extraterrestrial Intelligence) work between DSES and Skip Crilly *(2). The dual plots show we are observing the same astronomical object at known pointing angles, and is a good verification of the two systems observing together.
1. Reference: NRAO VLA 1.4 GHz survey.
2. Geographically-spaced Synchronized Signal Detection System” by Skip Crilly. Presentation on June 11, 2018 at the Society of Amateur Radio Astronomers Conference Green Bank Observatory, West Virginia, USA
Trip report and photos by Gary Agranat and Bill Miller, with contributions from the rest of the team.
We traveled to and worked at the Plishner radio telescope site during the weekend of July 20 to 23, 2018. Attending were: Steve Plock, Ed Corn, Paul Berge, Bill Miller, Dave Molter, Gary Agranat, and Tony Bigbee.This is a summary of what we did:
– The site received several days of heavy rains during the previous week. The bunker sump pumps were overwhelmed and the bunker was flooded. Steve and Paul spent a number of hours on Friday and Saturday morning clearing out the water and cleaning up. Steve reported clearing at least 60 gallons of water. Dave later on Saturday also spent time removing water and cleaning. Paul cleaned up some more water on Monday morning.
– On Saturday morning Paul and Bill filled in the conduit trench for the synchros.
– Ed installed a conduit and the power cables from the pedestal to the outhouse. He also started to install the cables from the outhouse that will lead to the RV power risers and connections. Ed said he intends on the next site trip to put in breakers, extend the wires to the RV locations, and install the outlets there.
– Paul put in wiring to the limit switch system, for azimuth and elevation limits of the dish travel. Paul stayed over Sunday to complete more of this.
– Paul and Bill installed the synchro indicator panel and reinstalled the manual dish steering control panel in the rack, in the com trailer. The panels in the rack will still need to be moved down one U space, to accommodate Skip’s TM-4 timing control. The Spectrum Analyzer was moved over to the adjacent rack. Paul installed the limit switch control panel under the manual control panel in the rack. They redid the panel configuration so that all the panel controls have azimuth on the left and elevation on the right to match convention. Bill relabeled all of the control panels to provide a more organized presentation of the switch and knob functions.
– Bill brought out the System 2 dish controller and laptop. It had worked well on the bench at home, but at first didn’t work at the site. After some frustration he called Ed Johnson and they worked through the problem. The static IP address of the computer had to be set and then the system communicated and could be tested. Paul stayed in the tower control deck while Bill drove the dish from the comm. trailer. A fairly serious problem was found and Ed was consulted again by phone. The watch dog timer was apparently timing out and dropping the power to the motor drives about 3 times a second. Seeing this they immediately shut it down. Bill took the system home to do a modification on the VFD power enable relay and to trouble shoot the reason for the time out. Once fixed, he will bring it back for more testing. Bill informed Dave Molter of the problem and asked that he not repeat the same issue in the motor drive control circuits of System 1. Bill also provided Dave with a linear power supply and some parts to complete System 1 controller.
– Bill also installed the latch on the System 2 Controller and temporarily installed the DB25 switch boxes in the control deck so we can switch between systems for test and maintenance.
– Steve and Gary worked on installing the MFJ auto-tuner for the FT-897 ham transceiver in the bunker. They found that the tuner would not power up, although the manual indicated that it should have. There is an alternative way to directly power the tuner, but they didn’t have the proper wiring. Steve gave Gary a wire on Monday, which can be used to connect the tuner directly to the power supply (located lower on the bench below the rigs). Gary also brought the mini-manual for the FT-897. It is like a checklist, and is useful for quickly finding menu settings.
– Gary used Dave’s antenna analyzer to check the SWR across the ham bands for the 5-BTV vertical antenna we installed by the bunker. The results show that the 10 and 15 meter bands are tuned well. The 20 meter band is biased towards the low end, with 14.0 MHz at an SWR of 1.4 and 14.350 MHz at an SWR of 2.8. The 40 meter band is biased towards the high end, with 7.0 MHz at an SWR of 3.1, the minimum of SWR 1.5 at about 7.23 MHz, and 7.3 MHz at SWR 1.8. 80 meters is tuned to a best frequency of about 3.9 MHz (SWR = 1.8), with a probable usable range from 3.87 to 3.947 MHz (where the SWR reaches 3.0). Gary noticed one of the smaller radials for the vertical broke in the middle. Perhaps it had been set a little too tightly.
– After checking with the analyzer Gary did some operating through the afternoon and evening on 10 through 40 meters, mostly on FT8 digital mode and some SSB on 10 meters. He was able to tune on the digital portion of all of those bands with his FT-950. During that time he made about a hundred contacts, which give the club some exposure to the ham community. As of this writing, about 50 confirmations were received on LOTW and eQSL. The QRZ page counter increased by about a hundred during that time as well. Propagation was poor, so that most contacts were just around the US. We did get some DX to Germany, Italy, and New Zealand. Gary also checked into the 12:30 pm Weather Net on 146.970 MHz on the Pikes Peak repeater, which is at a distance of over a hundred miles.
– Dave Molter brought his trailer out and the crew loaded up most of the remaining surplus wood container parts for Dave to dispose of.
– Tony Bigbee came out for the first time on Sunday. Bill gave him a tour of the facility and Tony went right to work, cleaned out the pedestal base room, and sorted out a lot of the surplus hardware there. Thanks Tony, this was greatly needed.
– The Britain family from Haswell came out on Sunday afternoon. Bill, Paul, and Tony gave Mr. and Mrs. Britain and their two ~10 year old boys impromptu presentations and tours of parts of the facility. Mrs. Britain is a teacher and very interested in working with DSES on a school & student outreach program in the area.
– Dave again tried the VHF talk-in radio system (on 146.46 MHz) while coming in to the site. We had a clear contact with him from about mile marker 128 on Highway 96. Gary tried communicating through the talk-in system coming from the south from Las Animas. He contacted Ed and could be heard from the first transmission at the county line, which is on a ridge. Gary again tried talking to the system with Bill while going out, traveling north to Haswell and then west on Highway 96 past mile marker 128. Gary could hear Bill clearly along most of the route, but Bill had some difficulty hearing Gary. Bill suspects the problem may be at the audio of the phone receiver in the comm. trailer.
The team considered this a successful trip.
Gary using Dave’s antenna analyzer to record SWR (standing wave ratio) values on the 5-Band Trap Vertical antenna for the HF ham frequencies it covers.