Posted by Myron Babcock, DSES Treasurer. Photos by Steve Plock, DSES Vice President.
Thanks to Skip Crilly for his $37K donation and to Steve Plock and Ed Corn for leading this effort to fulfill the dream of connecting the DSES Plishner Site to the AC Power Grid. Steve reported on Saturday December 9 that approximately 22 power poles, almost 5000 feet of wire, and a 25KVA transformer were installed last week. The Colorado Southeast Power Association worked 5 days in accomplishing this task. Saturday December 9, Steve Plock, Ed Corn, and Glenn Davis spent the day assisting local resident, Mark Nelson, from Haswell, CO in the trenching of approximately 600 feet of ground from the transformer pole area to the Southwest corner of the bunker area. Number 4/0 3 wire URD/with reduced neutral wire is now in the trench and once inspected by a Southeast Power Association representative the trench will be filled back in. Ed Corn has the necessary supplies for final connection to the bunker power panel. Once completed DSES will have 220 VAC 100 amp service in the communications trailer and 220 VAC 100 amp service in the bunker. Currently the plan is for the existing 30+KW propane generator to be disconnected. A decision will be made at a later date as to the disposition of this generator. Existing solar panels and batteries will continue to be used until such time as it is deemed the continuing expense out ways its usefulness.
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 following report was provided by Ed Corn and Steve Plock. Special thanks to Gary Agranat for providing the pictures.
This is a summary of our trip to Plishner Sunday 7-2-2017. Steve, Dave, Bill, Gary and my self made a very successful trip with a few exceptions.
Dave, Bill and Gary worked on the tumble weeds, cleaning all out of the ramp. I am positive they combined lost a bunch of weight (sweat down their backs) It was a bit warm. We all were involved in installing the chain link and construction safety fence around the perimeter of the ramp. We had enough fencing to do about ¾ of the perimeter. The rest will be completed the next trip down. This should take care of about 95% of the tumble weed problem.
Steve and I went to the comm. Trailer and re established the bunker battery monitor line. We discovered that Myron’s Hot Spot adapter has quit functioning. (DOA) I will get the unit back to Myron for exchange with his carrier. We need an agenda Item at the next engineering meeting to discuss the failure and preventative measures to prevent future failures.
Steve and I went to the generator tank and changed the wet leg valve. The excess flow check valve did check lock as designed so we did not have to depressurize the tank.
I corrected the wiring on the start/stop remote stations for the generator and Steve went to the bunker to help with the fencing.
After lunch we removed the feed and controller for the dish and Dave will deliver to Ray for modification.
I know I have forgotten some things the rest will have to fill in.
On the trip back Dave had a slow leak in a tire. Bill got him aired up and headed west. Steve and I headed home in my pick up. Just before Punkin Center I ran out of propane and switched fuels too late. This disabled my vehicle. So we put Steve in Bills van for the trip back to Ellicott and I called a favor from a friend who came down and recovered me. As of this writing the pick up is back on the road. Just too long of a day to make repairs on the road.
Myself and Dave Molter removed the multiband feed from the dish and Dave Molter delivered it to Ray’s house along with the feed control panel which I removed from the comm trailer.
The original station clock has been put back near operating position in comm trailer. Bill Miller inflated tires on bunker transport wagon. I removed the hotspot from the comm. trailer and when Myron is given a replacement from his wireless provider I recommend that we re-install it in the bunker because there is a much better environmental conditions for it to operate. The main valve on the 1000 gal tank was successfully replaced by myself and Ed Corn and tank can be filled after leak test is performed. Ed will contact Haswell Propane this week to arrange pressure test and fill. Please distribute.
Thanks, Steve KL7IZW
Additionally Steve and Ed loaded some of the old excess test gear and servers from the bunker onto Ed’s truck and sold them at the PPRAA ham fest the following Saturday. Bill brought back another one of the bad 6 volt deep cycle battery cores and will get the other from Ed to turn in for credit for two new batteries for the battery room on the comm. trailer.
The spiral staircase we constructed for the bunker, as a secondary/emergency exit, now being painted.
Steve and I (Ed) made a work trip to Plishner Sunday 8-7-16. There were several changes in schedules this weekend, but Steve and I decided to go down and get done what we could.
We arrived at 10:00 AM, opened the bunker and it was dry. The big trash can out side of the comm trailer had .3 to .5 inches of water in it, less whatever had evaporated.
Steve power loaded the 160 meter dipole at the bunker on all bands, so the raised height has helped. Given Steve could load the 160 dipole, he did not use the 80 meter dipole. He will load and prune that at a later date.
Steve then checked the voltages at each battery pack and compared them to their read outs. The delta on the bunker voltage meter is 2.2 volts for full charge. A voltage reading on the others of 12.1 or better volts indicates 95%+ voltage charge.
Steve and I installed the second air conditioner in the comm trailer. With approximately 2 hrs of running both air conditioners, the inside temperature was 11 degrees below outside temperature. When using the air conditioners, you must keep the side door closed and limit in and out.
Steve took caliper measurements of the pass through hole in the top center of the pedestal for Dave.
I started investigating the 2 dead generator plugs in the comm trailer, and found they route into the mechanical area at the tongue end of trailer. I will investigate and fix next trip.
We ran the generator for approximately 6 hours with a short load and encountered no problems. We secured sight and left at 4 PM.