This is a summary of the work done at the Plishner Radio Telescope site on June 20, 2020. Written by Bill Miller.
http://dses.science/wp-content/uploads/2020/06/Plishner-site-trip-summary-of-6-20-20.pdf
Category: Site Engineering
New work area in the science trailer, built by Bob Haggart
Bob Haggart (N0CTV) has been steadily improving the workspace of the science trailer at the Plishner radio telescope site. During the pulsar observation work on May 2, 2020, he completed building his latest enhancement: a partitioned work space at the east side of the science trailer. There is desktop space, which can be used for electronics building and testing. And there is additional shelf space, for better organization and storage.
Thank you Bob!
System 1 antenna control system update April 13, 2020
By Glenn Davis
I thought I would put out a System 1 status, so you can see what we’ve been working on the past couple of months. To quickly summarize: Lewis Putnam has been concentrating on the System 1 hardware design (Please see the hardware diagram below) to support automatic tracking of the Haswell Mount. Additionally he has been looking at the individual mount axis characteristics to see how well they can support sidereal tracking (See detail text below).
Phil Gage has supported myself looking at an Elevation axis movement issue we had seen at the site. We found a loose cable on our March 1 trip which appeared to be causing the elevation axis issues. Additionally, Phil has been working on the hardware/software interface for the Labjack hardware (Please see the hardware diagram below). The Labjack hardware, the U3 and JTick-DAC components, will be used to control the mount axis rates.
I have been updating the System 1 Hardware Simulator to support the Numato Relay Board and Labjack U3/JTick-DAC hardware devices. Additionally, I’ve been working on the hardware/software interface to the Numato Relay board. This device will be used to enable the drive controllers and control the direction of the Elevation Axis. Using the work completed by Phil and the Simulator modifications, I’ve been able to test and debug most of the automatic tracking software modifications and simulate the System 1 tracking celestial objects over large periods of time (hours).
Here is a more detail summary of the past work and future work on the System 1 team (Before site modifications are performed, we will present our design work to the DSES Engineering Team):
March 12 2020 Trip
- Purpose: Determine relationship between Az / El drive command voltages and rate resulting from command voltages
- Approach:
- Made measurements to calibrate mount Az and El drives (Rate as function of applied voltage)
- Took measurements separately for Azimuth and Elevation
- Measured both CW and CCW rates for Az and Up/Down rates for Elevation
- Varied voltage via Trailer Control Panel Az and El rate potentiometers from 0 to 5 volts (.2-volt increments for voltages below a volt and 1-volt increments from 1 volt to 5 volts.)
- Logged axis position data in System 1 software
- Captured measurements in Excel spreadsheet and plotted
- Findings:
- Plotted results indicate linear relationship between voltage and rate for both positive and negative rates for both axes.
- Performed linear fit to determine slope and intercept values that can be used to convert an axis rate into a command voltage.
- Unique Slope and intercept parameters will be used in System 1 software
- Slowest drive rates are .02 deg/sec for Az and .06 deg/sec for Elevation; lowest rates were consistent between positive and negative rates
- Rates needed for sidereal track are about an order of magnitude lower
- Will have to cycle axis drives on / off to achieve sidereal track rates
- Elevation Potentiometer voltage will not go to zero
- Lowest voltage is somewhat less than .2 volts
- Cause is unknown but potentiometer is most likely candidate
- Measurements for Elevation similar to results from August 2019 but measurements for Az significantly different from August results, unknown cause
- Measurements in March were more extensive and disciplined. Will use calibration from these measurements in the implementation of the software.
System 1 Mount Drive Interface Hardware Design/Implementation
- Progress:
- Completed hardware circuit design
- Interfaces to the tower drive electronics via the Jones Plug
- Uses a Labjack U3 device / TickDAC that provides two +-10-volt Digital Analog Convertors to enable setting Az / El axes control voltages
- Labjack has necessary digital I/O to interface to the axes encoders so downstream can be used to replace the now obsolete Integrity Systems digital I/O board
- Uses Numato 8 Relay Board to enable the drive controllers and control direction in the Elevation Axis
- Developed an approach to integrating circuit into the trailer rack
- Mount components on a small rack shelf about 6” deep
- Mount shelf on back rails of the Trailer Rack
- Move Jones cable from Manual control panel to System 1 Drive Control when using System 1 for drive control
- Acquired major components and some minor components – Numato 8 Relay Board, Labjack interface device, Jones plug and wire
- Completed hardware circuit design
- Next Steps:
- Colorado Springs
- Acquire remaining additional components – Switch, LEDs, resistors, rack shelf/panel
- Mount components on rack shelf and wire components together
- Integrate / test software with drive control assembly
- Site
- Install rack shelf / panel
- Install updated software
- Test / debug automated drive control
- Colorado Springs
Please pass this on to other individuals who may be interested.
Thank you.
Glenn Davis
Radio astronomy observing and antenna repair at the Plishner observatory, February 15, 2020
Participants: Rich Russel, Bob Haggart, Glenn Davis, Lewis Putnam, Bill Miller, and Gary Agranat.
Photos by Bill Miller and Gary Agranat.
We worked at the Plishner antenna site in Haswell on Saturday February 15, 2020. We had three projects:
- Attempt at observing a circumpolar pulsar, utilizing the System 1 manual tracking system. (Rich Russel, Glenn Davis, Lewis Putnam).
- Complete building and installing shelf space in the Communications (Operations) Trailer (Bob Haggard).
- Repair of the 3-element Yagi ham radio antenna, to realign the three elements (Gary Agranat, Bill Miller, Bob Haggard).
1. The major task of the day was an attempt at a science observing run of a circumpolar pulsar. This is one of the brighter puslars in the sky. And being circumpolar, it is always above the horizon, though it can still get relatively low to the horizon. The observing technique required continually pointing a the celestial coordinates and integrating the signal for at least a half hour. By integrating over time, the random noise tends to cancel more, leaving the actual radio source signal the time to accumulate and sum to a higher level than the noise floor.
2. Bob Haggart worked on completing the building of desk and shelf space in the Communications Operations Trailer. The additional space is actually important, as that gives us a means to organize and better utilize our work space, and not instead have items pile up randomly.
3. A third project was the repair of the front element of the 3-band Yagi ham radio antenna on the 40-foot tower. The front element had rotated slightly askew.
After the tower was raised back to vertical position, Bill and Gary slightly rearranged the positioning of the 80 meter dipole that is supported from a pulley on the tower. The repositioning separated the dipole with better clearance from other nearby wires
Rich Russel processed the observation data, but the processing did not bring out the pulsar. Troubleshooting is a topic at the February Science Meeting. Meanwhile, the System 1 antenna pointing system worked well.
The group finished up the work well before sunset, so that traveling back with the sun setting was not a significant issue. We had good weather for this trip, for a winter day in February. Our temperature was in the 40s F, which was actually midler than the 30s in Colorado Springs. And our wind was light.
Work trip at the Plishner antenna site, Saturday November 16, 2019
Text and photos by Gary Agranat.
As we do each third weekend of the month, we had a scheduled work day at our DSES Plishner radio astronomy antenna site in Haswell, Colorado. Our members who participated on this weekend were Steve Plock, Ed Corn, Ray Uberecken, and Gary Agranat. Work objectives were:
- Completion of installing the antennas and cables on the new 50 foot ham radio antenna tower.
- Servicing the 60-foot dish antenna feed.
I will save discussion of the 60-foot antenna feed for the Engineering Meeting minutes. That work was done by Steve Plock and Ray Uberecken. In this post I will describe the work we completed for the 50 foot tower.
With the 60 foot dish antenna rotated to the service tower, Steve worked at the antenna feed.
For our 50-foot tower work, we installed a second vertical antenna for normal contacts on the 2-meter VHF band. This gives us a second 2-meter band capability, independent of our already existing 2-meter band talk-in radio. We then installed coax cables for both of the 2 meter band antennas on the tower.
We also serviced the 80 and 160 meter band dipole antennas that the tower supports: 1) We replaced some of the nylon rope that lifts the dipole antennas to their deployed positions. Previously we had connected shorter pieces of rope and knotted those together. But the knots stuck in the pulleys, and we therefore replaced those with longer sections of rope without knots. 2) We neatened the arrangement of the wire antennas supported by the tower.
Captions to the photos provide more detials of the work.
After we serviced the ham and radio astronomy antennas, Steve made us lunch by smoking beef sausage in the grill. That was served with coleslaw and potato salad. Gary also brewed coffee.
After lunch I did some ham radio operating using the tri-band Yagi, and also the using the 80 and 160 meter dipoles. With the tri-bander, I first made a phone contact to Hawaii on 15 meters, before the bands got busy with the ARRL sweepstakes. Then I operated FT8: on 15 meters I mostly contacted South American stations (lots of Brazil), plus some US stations when they were there (including North Carolina and Montana). On 20 meters the band opened across the Pacific. We had many calls to us from Japan. Perhaps they saw our profile on QRZ, or perhaps they noticed our rare grid square. Also across the Pacific, we made two contacts with South Korea, one with mainland China, one with Indonesia, and one with Australia. The band became weaker for US and Canadian contacts, but we did have some of those too. I alternated going to 80 meters, and had a few more domestic contacts there. These were with our K0PRT station callsign. Later I also used my callsign, on 20, 80, and 160 meters. 160 meters had noise at the FT8 frequencies. But I went to the upper portion of that section of the band, which was just slightly better. I managed 4 contacts on 160 meters, to as far away as Kentucky. I would say our antennas were working well.
Within a few days we received a number of e QSL confirmation cards.
Ray left after lunch. Ed and Steve left before sunset. Steve tested the range of the new talk in radio antenna on the tower as he and Ed drove home away from the site. We had good contact to as far away as Sugar City. At JRs in Ordway, we could hear each other, but Steve needed to turn off his squelch. And at that point there were some slight dropouts. But we could still communicate. That is a great improvement for our talk-in system. Gary stayed and operated the ham station until a little after dark, and then closed up and departed too.
Antenna Raising
Plishner Antenna Site Work Trip Report. By Gary Agranat. Photos by Steve Plock.
Ed Corn, Steve Plock, and Gary Agranat traveled to the Plishner antenna site in Haswell this past Saturday, October 19, 2019. The team completed erecting the 50-foot ham radio tower.
Completing the tower erection involved several tasks:
- Installing the 3-band/3-element Yagi HF ham antenna,
- Installing the 2-meter band vertical antenna on top of that mast. This will be our new antenna for our VHF talk-in radio system.
- Installing two stand-off bracketed supports near the top of the tower on the sides, to raise and hold the 80 meter band and 160 meter band dipole wire antennas. This arrangement replaces the long pole that previously centrally supported those wire antennas. These bracket supports each have a pulley and rope, to raise and lower the wire antennas. The tower also supports a 6-meter band delta-loop antenna, which is simply tied from height.
- Securing the coax cables for the Yagi and vertical antennas along the side of the tower.
- Properly arranging the system of wires, coaxes, and support cables.
- Raising the 50-foot tower, which involves turning the winch system that rotates the tower up from its pivot plate at its base. The 50-foot tower is raised from a pulley system on a second smaller adjacent tower.
- Once the 50-foot tower is raised, securing 3 guy cables.
Steve tested the SWR of the 3-band Yagi antenna with an analyzer. The antenna elements had been measured and assembled on a previous trip, to be optimized for the middle of each of the operating bands, of the 10, 15 and 20 meter bands. Steve measured an SWR ratio of 1:1 (perfect) at 28.51 MHz for the 10 meter band, and 1:1 at 21.19 MHz for the 15 meter band. The 20 meter band resonated with an SWR of 1:1.35 at 14.16 MHz. This is excellent, and as expected.
For lunch, Steve treated us with smoked ribs from Broken Bones BBQ in Monument, with sauces, potato salad, and coleslaw. Gary brewed coffee. Also, the team met first at the firehouse in Ellicott. Gary baked orange-cranberry muffins. We ate our muffins at the firehouse, and shared the rest with the fire department crews there.
The team left the Plishner site by 4:30 pm.
The tower work began about a year ago. The work involved support and efforts by a number of team members. See our past posts from October 19-21, 2018 http://dses.science/plishner-site-report-for-the-weekend-of-october-19-21-2018, August 24, 2019 http://dses.science/plishner-work-trip-report-august-24-2019, and September 28, 2019 http://dses.science/work-site-trip-report-at-the-haswell-plishner-radio-telescope-site-september-28-2019.
The tower should significantly improve our capability to communicate long distances on the 10, 15, and 20 meter bands with the Yagi. The 2 meter band vertical should enable us to communicate on our talk-in VHF radio system to much further out.
Work Site Trip Report, at the Haswell Plishner Radio Telescope Site, September 28, 2019
by Gary Agranat
DSES Participants: Gary Agranat, Ed Corn, Bob Haggard, Bill Miller, Steve Plock.
Ed, Gary, and Bill met first at the Ellicott Fire Department, while Steve and Bob each traveled ahead solo. Ed encountered a problem with his truck and had to return home, but he passed the tower antenna mast and connector supplies to Bill. Steve and Bob arrived at the site by 9 AM, and Bill and Gary arrived by 10 AM.
We encountered light drizzling rain and low clouds on the route to the site, but the rain let up once we were on Highway 96 past Ordway. Steve called Ed to let us know the weather was good at the site. The weather completely cleared later, while the temperature remained comfortable.
Steve coordinated by phone with Skip Crilly and commenced a 48-hour long SETI drift scan at -7.5 degrees declination, run simultaneously with Skip’s antenna in New Hampshire. The 48 hour run will scan the -7.5 degree declination band twice, and therefore acquire a repeat set of data that can be compared with the first set.
Bob worked at the Communications Trailer, doing carpentry and painting work. He built a wood frame seal around one of the air conditioners, fabricated and painted a seal for the solar-powered fan, and painted the third work table he had added previously. Bob told me the trailer back door hadn’t been sealing — until recently — because it actually had not been closed properly. He closed the door properly and it is now sealed, without requiring further work.
Bob’s third table adds workspace in the communications trailer, and also helps keep the space better organized as well.
Bill, Steve, and Gary worked on preparing the 50-foot ham radio antenna tower.
Bill spliced the controller feed cable and wires for the antenna rotator, and verified proper operation, with some assistance from Gary. Bill used Steve’s crimping tools. The three of us then fed the controller cable through the dog house to the tower.
At the tower outside, the rotator was attached to its base plate, and that assembly was then attached to the tower.
When we tried to fit the mast in the holding tube at the top of the tower, we found that top opening was slightly damaged, and the mast wouldn’t fit in. We then took turns filing and grinding out the hole until the mast did fit properly. Steve applied a lubricating grease, to mitigate against the mast binding stuck when rotating. Eventually we successfully installed the mast to the rotator itself. We also retrieved a guy wire cable left at the communications trailer and attached it as the third guy wire connection for the top of the tower.
Before we left for the day, we had two visitors from Eads come to look at the site. We all spent a little while talking about the site and the work.
Addendum
By Gary Agranat
Bob was the first to leave, then Steve. Steve said he would check on Ed on the way home. Bill and I (Gary) convoyed out last.
While Bill and I were driving back to Colorado Springs, about an hour and a half into the trip back, an auto accident happened right in front of us, with a vehicle overturning.
The accident happened while we were driving westbound on Colorado Highway 94. It was early evening by then, about 5:30 pm, and the sun appeared above in the western sky. Bill and I had been talking on the VHF ham radio during our 2 1/2 hour drive back from the site. Bill was driving ahead of me.
A couple of miles before Rush, I saw three vehicles approaching from a long distance behind, moving faster than Bill and me, while we were going at about the speed limit. I mentioned the vehicles to Bill, and we stopped talking, anticipating they would choose to pass us soon. They did soon pass us, all three staying close to each other. We could see they were some sort of laborers, with equipment filling their vehicles and with ladders on top. The third vehicle passed us as we were going up a hill, with the solid yellow line on our side. Bill commented that car was taking risks, although they all were driving in a risky manner. There was no visibility over that hill. And furthermore we were driving into the sun. A couple of miles later we reached the town of Rush, where the speed limit lowers from 65 to 50 mph. As those three vehicles ahead approached the town, I suddenly saw the last one veer to the left side of the road, and then roll over, with its front turned facing the opposite direction. Bill and I both stopped, as did a driver heading in the oncoming direction who almost got hit. And several more cars stopped briefly. We saw one occupant lie in the grass, but he eventually got up.
Bill had a better view of the accident ahead of me. It looked to him like one of the three vehicles ahead suddenly slowed as he reached the town with the lower speed limit. The sun was right above and ahead of us, which created a greater visibility challenge. The sudden slowing apparently caught the last driver off guard, as he swerved to the right to avoid the vehicle ahead of him. But that put his right side of his car in the grass there, which caused a tire blowout and a swerve then to the left. And he overturned.
The volunteer fire department nearby responded relatively quickly. But we waited about 2 hours for a sheriff’s deputy to arrive, and then another hour for a State Patrol officer to arrive. The State Patrol was who we had to give our witness statements to. We didn’t finish with that until 8:30 pm, and I didn’t get home until 9:30.
The driver of the overturned vehicle eventually got up, but he refused medical help, although we wondered if he nonetheless might have been hurt.
Meanwhile the communities there are small, and everyone there knows everyone else. The other driver who stayed was a local woman school teacher. We chatted with her and also the volunteer firefighters, and with some of the neighbors who stopped to see if everyone was OK.
The State Patrol officer later explained to us that there were 6 accidents in the region called in within a period of 5 minutes, when our accident happened. One happened just about 9 miles further west from us on Highway 94, in the town of Yoder. That accident had injuries, and some of the firefighters who were with us then had to leave to respond to the other accident.
At a minimum, this is a reminder to take care to drive safely, especially with limiting conditions like the sun setting ahead.
Plishner Work Trip Report – August 24, 2019
By Gary Agranat
Participants: Ed Corn, Steve Plock, Gary Agranat.
Ed, Steve, and I traveled to our radio telescope site, leaving from the Ellicott Fire Department a little after 7:30 am. We encountered just a little fog on the way.
Steve worked primarily on troubleshooting the amplifier failure on the 60-foot antenna fiber optic feed. Steve found a power supply no longer functioned. He wrote me later, “Damaged parts have been ordered and will be replaced at the earliest convenience.”
Ed Corn and I worked on assembling the 3-element tri-band Yagi antenna from Myron Babcock, and then the ham radio tower by the bunker, on which the Yagi antenna will go. We measured and reassembled the three Yagi antenna elements and the boom support for them. We’ll wait to combine those until we are ready to attach the antenna to a mast and on to the tower. The antenna will operate on the ham 10, 15, and 20 meter bands. We decided to set the lengths so that the antenna tunes best in the center portions of the bands.
We assembled the tower components out to a length of 50 feet, including the top that will hold the rotor. The tower is now designed and built to rotate from a pivot point next to the existing tower that had been started earlier. Ed climbed that original tower to install the pulley; the pulley leverages and pulls up the 50-foot tower by rotation at the pivot. We tested lifting the 50 foot tower with the hand crank winch that I think came from Steve. The design works. We eventually will need to take down the mast that supports the 80 and 160 meter dipole antennas, to complete the tower build-out. We plan to re-attaching those antennas to the tower itself, when we are ready to complete the tower. Ed has already fabricated two standoffs that will attach to the sides of the tower, and centrally support the dipole antennas.
Ed from time to time went to help Steve. And Steve once in a while came to help with the tower assembly.
Ed removed metal plugging the insides from a previous tower connection. 
We had a lunch break together in the bunker. I brought a small coffee maker and brewed coffee for Ed and me.
The weather was good, considering the heat we’ve been having lately. High cirrostratus and mid level clouds from storms in the distance covered us for the afternoon, and kept the heat and sunshine comfortable. We saw rain showers in the far distance, but those never came close enough to bother us. The bunker thermometer read 75 F, and outdoors was probably just a little warmer.
During a break I got on the air at the bunker station, and made 12 contacts for QSO parties that were running: 1 to Hawaii, 5 to Ohio, and 6 to Kansas, on CW and SSB, on 20 and 40 meters. I submitted our logs to those QSO parties later.
For the team, Gary Agranat.
Radio Telescope Site Report, System 1 Team, August 17, 2019, by Glenn Davis
Here is a quick site trip report on the work the System 1 team (Phil Gage, Lewis Putnam, Dave Molter and Glenn Davis) completed at the Haswell Site yesterday (8/17/2019):
- We installed Version 4.0 of the System 1 software. This version includes a major new capability that supports manual tracking of astronomical objects. I would like to demonstrate this capability at the next Science or Engineering meeting.
- Version 4 included a software update to fix the Elevation Axis Bounce Issue (Erroneous Elevation Axis Status) that was identified earlier this summer and has been investigated for several years. The problem was related to the Elevation Axis Integrity Instruments 232M200 I/O module. Due to a board related hardware problem, the I/O board was always reporting bit 2 of the encoder position data as “stuck” on (1) which would create erroneous Elevation encoder data. The fix required both a hardware and software modification. The hardware modification included moving the bit 2 pin to an unused position on the connector to the I/O module (see #3) then provide a software fix that would read data from this new bit position and re-incorporate the bit data back into the Elevation encoder position data – bypassing the bad bit. This hardware/software solution has fixed the problem. The Elevation Axis is now providing the correct encoder positions through it’s range of motion and the “bouncing” has been eliminated.
- Dave Molter moved and soldered the “bad” Elevation Axis hardware pin to support the software modification that fixes the Elevation Axis Bounce issue.
- Collected Voltage to Rate information for both axis – data below:
| Voltage (V) | Azimuth Rates (Degs/Sec) | Notes |
| 0.00 | 0.00 | Minimum Potentiometer Setting |
| 0.20 | 0.04 | |
| 0.39 | 0.08 | |
| 0.50 | 0.11 | Normal Potentiometer Setting |
| 0.75 | 0.17 | |
| 1.50 | 0.33 |
| Voltage (V) | Elevation Rates (Degs/Sec) | Notes |
| 0.05 | 0.06 | Minimum Potentiometer Setting |
| 0.17 | 0.07 | |
| 0.35 | 0.08 | |
| 0.75 | 0.11 | |
| 1.52 | 0.15 | Normal Potentiometer Setting |
| 3.72 | 0.30 | |
| 4.24 | 0.34 | |
| 5.00 | 0.42 |
Please note: We were unable to produce zero rates on the elevation axis – even with the potentiometer turn all the way down.
Additionally, though we believe we returned the potentiometers back to their normal positions, whoever returns to the site for the next data collection, please ensure the potentiometers are at their normal positions before use.
Glenn Davis
Plishner Antenna Site Work Trip Reports for July 10 & 20, 2019
By Ed Corn
Trip Report for July 10
My wife and I spent the day at the site cleaning up the last of the electric basic infrastructure build out. That portion is complete with the following items completed.
- Basic plug ins complete including a GFI plug near the sink and one in the bathroom for portable heater.
- A pre wire and extra switch in bathroom for future ex-host fan and an electric water heater for shower and kitchen sink.
- Box and wiring for sewer pump when that project starts.
- Wall switch and permanent light in sleeping area.
- The tunnel lights now have a control switch at both ends.
- 240 volt plugins for amplifiers at the Amateur operating position.
- The sub main electric panel in the battery room is complete and the main panel has the trim cover installed.
There will be extra plugs and services that will be needed in the future but basic build out is complete.
* *
Scheduled Maintenance Trip Report for July 20
Steve and I went down Friday the 19th. We met Paul Berge at the house in Haswell. Paul and his wife came down Thursday and stayed over Thursday and Friday nights. Steve and I stayed in the bunker Friday night.
Paul worked on finishing installing the control wiring in the pedestal in the conduit for mechanical protection, and he installed heavy duty override switches in the override panel in the comm trailer. He also gathered information for some updates on the control wiring. He will be working on the updates at his home computer.
Steve worked on the fiber link from the feed point to the comm trailer. The wind came up Saturday so Steve will complete work later as the wind was a safety issue trying to work up at the feed point. Steve did say the az/el readout worked after cycling power.
I have the two 30 amp plug-in circuits at the old generator building completed to give us 2 more RV parking spots with heavy enough power to run 1 air conditioner in each RV. Just for information to turn lights on in the generator building you will have to turn the circuit breakers on in the distribution panel in the middle of the North wall.