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.
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.
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 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.
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.
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.
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.
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.
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.
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:
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.
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
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.
DSES Plishner Site Trip Report 6-14-2019 By: Bill Miller, Bob Haggart. Photos by Bob Haggart.
Location: Plishner Radio and Space Science Center, Haswell, Co. Attendance: Steve Plock, Rich Russel, Jonathon Ayers, Floyd Glick, Bob Haggart, Bill Miller
Accuracy: This is only a summary of my work on Friday and Bob Haggart trip from his report for Saturday and you should add your own and correct anything I missed. WKM.
Bill Miller’s Work Trip Report, Friday, June 14th Bill was the first to arrive at the site about 10:15 on Friday 6/14 and started by opening the trailer and removing the exhaust fan cover. He lubricated and reattaching the fan wires, started the air conditioners, swept the Comm. trailer floor and removed the mud left from the last visit. Steve came in shortly after and he and Bill went to the top of the tower to inspect the Liquid-tight conduit that Steve had previously installed for the elevation position synchro wiring.
Jonathon Ayers came in and assisted Bill to hook up the wiring to the synchros on the elevation axis in the top deck.
Bill then got some assistance from Floyd Glick while hooking up the wiring in the control deck of the dish pedestal. Thank you to Jonathon and Floyd. The goal was to attach the Elevation position synchro encoders to the synchro panel in the Comm. trailer. This would match to connections of the Azimuth synchros previously installed. It would complete the synchro dish position indicator system which is an accurate minimal tech backup dish positioning system that needs no computer.
Bill was under a tight schedule as Rich had a pulsar observation planned to start at 3:30. Bill tested the system and it worked initially but then started tripping the ground fault interrupter on the synchro panel within a few minutes indicating that the insulation or electrical clearance of the elevation connections was breaking down somewhere in the path. Because this circuit is 120VAC, the ground fault interrupter is critical to safe the system with the many intermediate connections and it did its job. (Caution) Bill unplugged the synchro panel from AC and it should be left unplugged until we have a chance to trace down the fault in the elevation wiring. It is most likely in the old terminal box in the control deck, moisture in the system or hasty wiring in the elevation axis Encoder box. I also believe that the synchros in the elevation axis box are either bad or incompatible and should be changed out and matched to those in the trailer synchro panel. Ed Johnson has a box of synchros from the bunker.
Bill had to leave about 4:00PM while Rich, Floyd and Steve stayed to make their Pulsar observation. This seemed to be going well but the large storm was brewing in the area and I suspect they had to abandon the site that evening.
From Bob Haggard’s Work Trip Report. Saturday, June 15th Arrived at the DSES site 8:35am. Opened gate, opened the bunker to retrieve keys. Noticed the dish was setting at about 45 degrees. Opened the Ops trailer and the battery box for 110V AC power. Mounted the solar powered, dusk to dawn, LED porch light. Removed the camera and the broken rear trailer window. Installed the clear window and camera right side up. (there you go Rich) The molding to hold the window in was rotten, have to make 4 new ones. The putty was too old to be used, will need more on next trip.
Removed two folding chairs from battery box and stored them in the OPs trailer under the table next to the filing cabinet. Stored the donated table saw and stand in the battery box. Picked up all unused unwanted lumber (there you go Steve)
Secured the battery box and the Ops trailer. Returned the keys to the desk and secured the bunker and gate. Secured the main gate and departed at 2:45.
No one else showed up for this work day.
The weather was perfect, a mild breeze, just enough to keep you cool while working in the hot sun.
(Editor’s Note: This is Ed Corn’s report of our work at the Plishner radio telescope site during the weekend of May 18, 2019 – Gary, WA2JQZ)
I arrived about 9:30 AM and proceeded to the generator shed to install breakers and to survey the conduit route for 2 extra camper hook ups. The breaker box is ready. I will run conduit and wiring during another trip prior to the open house.
Steve Plock arrived shortly there after. We traveled separately so Steve could stay over with Paul Berge, as I have a graduation to attend on Sunday. We looked at the ham radio tower project. All the hardware is on site but tower climbing is out for most of us. Steve decided we will assemble the tower on the ground, and tip it up with a winch at a later trip. We need a few extra parts to do this which are easily obtained or fabricated. Gary Agranat arrived and went to work on the vertical antenna. The vertical was damaged during the blizzard storm several weeks ago. He has a list of all needed parts for fixing on the next trip.
Steve moved the dish to the work stand and checked the control voltage for the feed to the preamps, and adjusted for voltage drop in the line from the communications trailer.
Steve and Gary then worked on tuning the 16o meter and 80 meter wire antennas. (Gary added: We trimmed the lengths to retune the antennas to about the center of the ham bands. The 160 meter antenna was tuned to 1.9 MHz, with a best SWR of 1.7:1. The 80 meter antenna was tuned with an SWR of 1:1 from 3.8 to 3.9 MHz. Before the tuning, each antenna was slightly long, which therefore gave better performance at the low ends of the bands. The retuning enabled better resonance in the phone portion of the bands, where several members like to participate in nets.)
I moved into the bunker and pulled wire for the sub main panel in the battery room, in preparation for the hot water heater for the sink and shower and the sewer pump system. The sub main is complete, ready for extension of the conduit runs on a future trip.
Paul arrived late afternoon and stayed the weekend with several items he wanted to work on.
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.
Attendance: Gary Agranat, Ed Corn, Floyd Glick, Glenn Davis, Steve Plock, Rich Russel, Tony Bigbee, Ray Uberecken, Dave Molter, Jon Richardson, Bill Miller
Attending Remotely via TeamViewer: Skip Crilly, Dayton Jones, Jamie Riggs
Last Trips: Oct 19 Observation Trip. Oct 20 Work trip for ED. Steve, Hans, Gary, Paul
Next Trips to site: The regularly scheduled 3rd Saturday of the month, Saturday Nov 17th. Observation the night before on Nov 16th
DSES Technical and Operations Meeting- 2nd Monday of Every Month
DSES Science Meeting – 4th Monday of Every Month
Accuracy: The notes for this meeting may be out of order. This was done to group the discussion into subjects for better clarity and continuity, so they are not true chronological minutes. As always if I have misstated, omitted or misrepresented anyone please feel free to correct me WKM.
Agenda and Notes
Ray Uberecken has his mount ready to install a 12 ft dish with capability up thru the KU band. He needs to move the dish from the KCME radio station to his site in Payton. The dish F/D ratio is the same as the 60 ft Haswell dish, so the 12 ft dish could be used to prototype feeds and receivers for the Plishner site. Ray would like some volunteers from the DSES to help move it next Sunday the 28th at 10AM. (Note: Recent change of plans. Ray will hire a crane to pick the dish out of the KCME yard enclosure before disassembly. This is currently scheduled for 7 AM Saturday, November 10th.) He could use some volunteers, power drills with sockets and a trailer. KCME is at Fontanero and 1921 N. Weber in. Bill will send an EMAIL out to the group.
Once the dish is in place the first thing that Ray will install is a Dicke Switch.
Ray also wants to know if we want to use the 8 channel UHF remote at the site for reset and control of the systems. We have not been using it, but that is available and installed in the communications trailer rack and can be commanded remotely from Ray’s residence.
Ray has also started his optical observatory with 8 inch Celestron and a good refractor at his residence.
Dr. Rich Russel reviewed his new Radio Astronomy Guide Rev. 3.
The RA/Dec of many of the objects are from both celestial coordinate year 1950 epoch and year 2000 epoch, so needs updating.
The output of the SpectraCyber is in volts and a translation to Jansky is needed.
Rich and Gary observed a number of sources on the Oct. 19th observation trip.
Some source positions were very good. Others were not. This may indicate a pointing error or other system issue.
They were getting a lot of clear source signatures but don’t know what many of them were. Rich would like to do cross galactic scans while changing declination to map the whole area in the future.
Cassiopeia A, Cas-A, was thought to be seen, but at a relatively low amplitude. Cas-A, being a 2200 Jy source it should have been clearly seen but they weren’t sure they had it.
Sagittarius A was strong and had the instrument setup with too high of gain, resulting in scale saturation.
Special sources 1 and 2 were studied.
The special source 2, a contact binary star is getting close to a supernova event in a few years, and we want to baseline it and get ready to observe the supernova emission.
To find objects Gary used the tables in Rich’s observing guide and in the Data Book “Astrophysical Data: Planets and Stars” by Kenneth R. Lang.
The V notch object that Tony studied was not tried in Rich and Gary’s session.
Rich and Gary also did an experiment to measure the hydrogen (HI) Line Doppler shift and therefor the velocity along the galactic plane. They were able to get reasonable hydrogen measurements of the galaxy’s rotational velocity at multiple points from the center out to the radius of the sun.
Rich plotted these observations and got a curve that is in the ballpark but a little different than the published data on similar measurements. This is the first time that the Galactic angular velocity measurement has been attempted with the 60 ft. dish.
See Dr. Rich Russel’s attached Science Meeting presentation for more detail on the site trip and the observations mentioned above.
Tony Bigbee also went to the site for the observing session last week. Tony installed onto the system after Rich and Gary had finished. He did not get the expected results on the RASDR 4 receiver when attached to the 60 ft. dish over the weekend. He thought that the issue may be with the pointing accuracy of the System 1 controller. We used System 2 at the open house when Tony had very good results but did not get the same on this last weekend’s observation session using System 1. Tony looked for the V notch absorption object and is using a new code to calculate the source amplitude. He did not get good results on this and suspects pointing error.
He calculated the curves for the open house and last weekend’s observations showing time and discovered that these are different indicating that something is wrong between the two.
Tony did a Mollweide projection plot like the one below. In Tony’s plot the green line is the meridian, the blue line is the galactic plane. The black X is the position of the telescope. See Tony Bigbee’s actual plot when he posts or sends it out.
Rich suggests that anyone going down to observe should measure some of these same sources and get data to compare their results.
SkipCrilly says we have aligned NRAO 5690 at Greenbank and Haswell sites three times using the System 1 controller and it seems to be positioning correctly. Steve can do an additional observation next week, Tuesday and Wed and verify the alignment.
Another difference from the open house observation was that Steve Plock added the alternate cavity filter configuration.
As mentioned previously the coordinates of some of the sources are from celestial coordinate year 1950 epoch and year 2000 epoch so may be different positions now due to precession and galactic movement. A mathematical correction to the coordinates may be required to make an accurate set of coordinates for the current date. However, the small difference afforded by this is probably within the capture angle of the dish.
Glenn Davis says that his NTP time sever may be useful to improve the accuracy of the pointing systems.
Bill Miller said that the System 1 controller may still have a discontinuous elevation reading error. This was seen previously this summer and has not been fixed. This could contribute to a pointing error and inaccuracy on some coordinates.
Anyone going to do observations at the site should try to replicate the studies of the observation guide and use the Observation Checklist to make their session useful and comparative.
Currently the LMST is close to local time, and so one needs to consider this and observe in the evening instead of afternoon.
See the back of Rich Russel’s observing guide for dish rules and limits. An observation data sheet and suggestions are available in the back of the guide as well.
We need a list of some calibration sources to start all observing session with, to be sure that the pointing system is working properly and that it isn’t broken with new SW drops. Also, we hope the voltages we measure from calibration sources (with known Jansky levels), will enable us to derive the Janskies of other objects we wish to observe. Janskies are the measure of the flux density that the antenna receives.
Three papers have been accepted in the next SARA journal.
“The Deep Space Exploration Society 2018 Perseid Meteor Shower Open House”. By Bill Miller, Gary Agranat. Deep Space Exploration Society.
“SpectraCyber Neutral Hydrogen Measurements using the Deep Space Exploration Society 60 – foot Antenna System“. By Richard Russel D.Cs., Ae.E.; Gary Agranat. Deep Space Exploration Society.
“Dark HI Cloud Observation using the Deep Space Exploration Society Plishner 18 – Meter Dish with the RASDR4“. By Tony Bigbee, Richard Russel, Steve Plock. Deep Space Exploration Society.
Skip Crilly discussed his new 28 ft. antenna that has a 5 pixel or 5 separate antenna segment feed and is mounted on a cargo trailer but will be used mostly for SETI. The antenna may not be large enough to observe the strange signals we have seen. File size is one challenge since it is inversely proportional to the gain and noise ratio.
Meeting was adjourned after much secondary discussions not captured here.
Old 9/24/2018 Agenda and Notes from last science meeting:
Glenn Davis proposes a graphical user interface called Astro Guide that would allow better guiding and tracking of radio sources.
Rich’s presentation and overview of the radio astronomy guide
Started with Floyd’s list
Added the 1420 MHz sources from the book “Tools of Radio Astronomy” by K Rohlfs and T Wilson.
Added the hydrogen measurements from K5SO, Dr. Joe Martin who has provided signature images of the objects.
Gary, Jay Wilson, Rich and Steve all went to the site on 9/22 and did observations using the 60 foot dish.
Used Spectra Cyber
Used system 1 pointing
Used the new setup with the cavity filter
Limit switches are set at +/-15 ether way of north. CCW to 345. CW to 015.
Gary got great pictures of the event.
Need screen print capability to capture the Spectra Cyber parameters display.
The Spectra Cyber SW is easy to take the data and use it.
Need a Lap Top with a com 2 serial port to attach the spectra cyber. This is difficult because most of the Serial to USB port adapters don’t want to set for Com1 or Com2.
Need to do calibration sources before and after observation of an observed object and keep all settings on the Spectra Cyber the same.
From Tony, “To avoid problems of solar interference all observations were made between sunset and sunrise. Most scans were taken with the telescope on the meridian.” Galt and Kennedy, 1968, ‘Survey of Radio Sources Observed in the Continuum near 1420 MHz, Declinations —5° to +70°’ http://adsabs.harvard.edu/abs/1968AJ…..73..135G
Rich presented a number of plots from their observations. See Rich’s report.
The scan across the galaxy were at one RA. The radio hot area was offset from the optical.
The galactic rotation rate was also observed.
Got a lot of raw data, learned how to catalog it and analyze it.
The calibration sources did not show any signal above the noise.
Got good data for Sagittarius A, SAG A.
3 Papers have been submitted for the SARA Journal.
The Western SARA conference is in Boulder in March.