Here is our report of our work trip at the Plishner radio telescope site in Haswell, on the weekend of September 14-16, 2018. Opens as a PDF file. Illustrated with photos.
By Bill Miller and Gary Agranat.
Here is our report of our work trip at the Plishner radio telescope site in Haswell, on the weekend of September 14-16, 2018. Opens as a PDF file. Illustrated with photos.
By Bill Miller and Gary Agranat.
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.
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:
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.
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.
– 73, Gary Agranat, WA2JQZ
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 June 2018.
[ http://dses.science/wp-content/uploads/2018/06/SARA_GBO_2018_Crilly_73N_3_PDF.pdf ]
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.
I thought this might give a nice change of pace, and also be appropriate and fun. – Gary
By Larry Maurice
Why do we do what we do?
Why is it done by so few?
The answer is vague, but maybe today
I’ll try and explain it to you
We do it for the FUN!
To watch the rising sun
To see the sparrow and the hawk on high at play
To watch the mountains rise from inside a darkened sky
To feel the muscle of the earth at the break of day
Great grey granite peaks
The place where your own spirit speaks
In a language that you interpret as you choose
We do it because we know that no matter how it goes
Life is not about the goods that you win or lose
We do it because we are never at our best
When we are setting down at rest,
Like those who only sit and plan and plan
But we are most at ease
When we are part of the breeze
Pitting ourselves and our stock against the land
In our life the job is never done
We always need another sun
It’s just handled for the moment
And we thrive on life’s hard rules
And we are often spoke as fools
But in the hardest job well done
There is contentment
Most of us take great pride
In the work
And the ride
And in the smugness of being where we want to be
I hope all of you
Need and love the work you do
And if not
It’s never too late
To set the Cowboy in you free.
Grassy Lake, Jackson Meadow, 1991
This poem appeared in a guide to learn CW (Morse Code) by Ron Stark KU7Y, distributed by QRP Amateur Radio Club International.
Trip report by Bill Miller, with editing and photos by Gary Agranat.
This is a report of our work at the Plishner radio telescope antenna site during the weekend of June 16 & 17, 2018.
Attendance: Gary Agranat, Paul Berge, Ed Corn, Michael Lowe, Bill Miller, Dave Molter, Steve Plock.
Vertical Multi-band Antenna Radials: Gary performed a set of SWR (Standing Wave Ratio) measurements with an antenna analyzer on the vertical multi-band antenna, which was installed last April for the ham radio station at the bunker. He then installed 17 radials at the antenna base. On the next trip he plans to retake antenna analyzer measurements, and also do some digital radio operating, to compare characteristics before the radials were installed.
New Rest Room: Steve Plock and Ed Corn continued work on the new rest room/out house. This is a refit of one of the rail road buildings previously used for storage. They added tie down cables to prevent it from succumbing to the winds. It will be fit with a chemical toilet and there is a waste receptacle behind the building for easy dumping access. This will greatly improve our facility for public visits such as the open house on August 11th.
Synchro Installation: Bill worked on the dish Az/El Synchro installation as a simple backup pointing system for the dish. On the previous trip Bill and Steve installed an additional 2” conduit from the Comm Trailer to the pedestal. Myron had helped pull in the 15-conductor cable. On this trip Ed Corn helped finish off the conduit and drilled 2” access holes in the trailer floor and pedestal. Bill installed the cable up the pedestal structure and terminated it in the terminal box above the control deck. He also terminated the other end on the synchro panel in the comm trailer. The azimuth synchros were hooked up and they worked. One problem remains with the fine azimuth synchro. The Elevation synchro connection on the dish will be made in a future trip.
Pointing System 1: Bill and Dave examined what would be needed to complete system 1. Bill has a linear power supply in the works to replace the noisy switcher. He also has an amplifier and watch dog circuit for the control function in progress. Dave suggested removing the system 1 box on the next trip and bring it back to Colorado Springs to install these and other software modifications for Glenn to test. Currently system 1 only has position feedback and no direct control.
Pointing System 2: System 2 currently has all the circuitry for full position reporting and tracking control. As reported last time, Bill is working to transfer programs between computers and working on the system 1 at home and will reinstall on the next trip.
Dish Restoration and Maintenance: Paul Berge came down Saturday afternoon and stayed for work Sunday. Paul checked our Synchro system and made some valuable suggestions. He worked on other maintenance items on the dish including making a rubber bellows and seal to keep the water and birds out of the multiple cables feeding down through the center of the azimuth axes. He also started working on wiring and setting up the Elevation and Azimuth limit switches.
Other Items: Dave Molter finished the tear out of the 12-foot fiberglass dish and support concrete from Sue’s yard in Sugar City. He transported it down to the site on his trailer and unloaded it for future use. Bill and Dave pulled a vertical antenna and base insulator out of the pedestal and loaded it on Dave’s trailer. Dave returned the antenna to Michael Lowe in Pueblo who originally brought it to the site.
While we worked on Saturday, there was harvesting in the surrounding fields.
We worked at the antenna site in Haswell from Friday May 18 through Sunday May 20, 2018. We essentially worked in two teams. The first team was at the site from Friday afternoon through Sunday morning, with some in that team just coming on Saturday. The second team worked Sunday afternoon.
Accomplishments for this work trip:
Contributors to this post are Steve Plock, Bill Miller, and Dave Molter, with additional writing and editing by Gary Agranat. Photos by Bill Miller, Gary Agranat, and Steve Plock. Working on this trip also were Aaron Reid, Paul Berge, and Floyd Glick.
Thanks to everyone who helped on this trip.
I arrived Friday afternoon. Paul Berge arrived shortly after and Aaron Reid not long after that. We ate a little dinner and turned in. Right around sundown it started raining. It rained most of the night and stopped around sunrise. Because it had rained all night it was pretty muddy outside. We helped Aaron unload his tractor off of his trailer. We then started cleaning debris out of the 600′ trench ahead of the tractor that was pushing the low side hill made by the ditch witch down into the trench. We then placed the barrier tape into the trench ahead of the tractor which pushed the high side berm into the trench as well. We tromped through a lot of mud that morning.
Next we cleaned out the building that would become the new outhouse.
Then Steve and Paul ran an 85′ coax cable from the new vertical into the bunker. When Gary arrived he checked the antenna out using Ray’s Intellituner as a crude analyzer. It checked out OK on 80-40-20-15 and 10 meter phone portions of these bands.
Floyd Glick showed up and started helping out to get the outhouse up on the old platform that had the battery box building on it. We used a couple of chains and the tractor and some boards to accomplish this. Next I marked the spot the Ed had wished the pit to be placed and Aaron dug it to a depth of about 5 ½’. All three of us worked together to cover the pit with railroad ties.
Next I marked the 2nd trench, from the pedestal to the Comm. trailer, after consulting with Paul to stay clear of the existing conduit. By that time everyone was pretty tired and turned in for another, night. Sunday morning everyone left before noon. I led Aaron north on County Road 20 until we hit CO Highway 96 up in Haswell. Told him to pick up Highway 287 north in Eads.
On our last trip we installed a donated 5-band trap vertical antenna for our ham radio station at the bunker. Although we had radial wires with the donation, we didn’t yet have time to install those.
Before I arrived on this trip, Steve Plock installed an 85 foot coax cable from the antenna base, through the doghouse, to the ham station in the bunker. Although he didn’t try to make any contacts, he reported good signal reception using the IC 706 on 40 and 20 meters, including DX from Europe. The IC 706 has an attached automatic antenna tuner, and he reported there was good tuning on all of the bands.
I decided to hold off installing the antenna radial wires, and instead check how well we could operate in the current set-up. I systematically checked the SWR and the ability to tune on all 5 wavelength bands of the vertical (80, 40, 20, 15, and 10 meters). I confirmed we could tune well enough on all of the band spectrum except for the 20 meter Morse Code segment. I tried making some phone contacts but succeeded only with one. And for the IC 706 I didn’t have the right connector for my CW key. I therefore instead set up a Yaesu FT-950 with a SignaLink digital interface matched for it. With that I succeeded in making 30 FT-8 digital contacts, most on 40 and a few on 20 meters. I was able to do some DX (distance contacts) on 40 meters: IU8CNE (Italy) and LU5VV (Argentina). Plus we made one New Zealand contact, with ZL2IFB, on 15 meters, but otherwise DX conditions were poor. The other contacts were across the U.S. and to northeast Canada. I also had one traditional Morse Code CW chat on 40 meters with K3WAS in Kansas. And so the vertical antenna without the radials does work, and we do get out at least domestically. The somewhat poor FT-8 DX suggests radials may be worth installing still, although I cannot rule out that we had poor band conditions.
Log of contacts:
K5BZI 20m SSB TX
K4SHA 40m FT8 AL
W6GRD 20m FT8 CA
K9ZJ 20m FT8 WI
VA3HP 40m FT8 ON, Canada
K2PS 40m FT8 FL
KG7RZD 40m FT8 WA
K3WAS 40m CW KS
K0CHW 20m FT8 SD
N9RS 40m FT8 WI
AB1HL 40m FT8 MA
K6SJT 40m FT8 CA
K7ZYV 40m FT8 MS
NA8N 40m FT8 OH
K6KHB 40m FT8 CA
WA6PHR 40m FT8 CA
AE8S 40m FT8 OH
N4RLG 40m FT8 KY
KB7ZDM 40m FT8 OR
KC1GWX 40m FT8 MA
WA2HIP 20m FT8 ME
VA3CTX 20m FT8 ON, Canada
ZL2IFB 15m FT8 New Zealand
VE2GYA 40m FT8 QC, Canada
N4ZI 40m FT8 TN
KB5DXO 40m FT8 MS
LU5VV 40m FT8 Argentina
N8NXG 40m FT8 FL
K4RGN 40m FT8 NC
WY7CDL 40m FT8 WY
IU8CNE 40m FT8 Italy
K9QVB 20m FT8 IL
AB5CA 40m FT8 TX
On Sunday I met Bill Miller in Sugar City, and tore down a 10 foot dish that was donated to DSES. The dish was left at the residence until a trailer can be provided to remove the parts. The base post was not removed from the concrete and will need to be done on a future trip. This effort also led to 3 more fiberglass 10 foot antennas identified which will be donated and obtained at a future date.
When we got to the site we energized the dish drives and observed noise on the elevation encoder lines shown by the LEDs flickering and watching the position signal on an Oscilloscope. Ferrite beads were installed around the elevation encoder lines. There was no change to the amount of noise present on the wires. The elevation readout cover was removed and the cable was removed from the encoder. The connector was opened to allow inspection of the wiring. The cable shield drain wire was temporarily jumpered to the frame ground. The signal noise was reduced. The cable drain wire was connected to pin S of the encoder (Frame Ground). A jumper wire was also attached to the drain wire and connected to the encoder body. The mount was run in elevation and azimuth and the readout was stable, the LED did not flicker. The dish control was transferred to the trailer. The control panel was used to move the mount in azimuth and elevation. The readout computer was energized and the remainder of the day was spent looking for the paper that contained the logon to the portable computer.
It was observed that the electrical trench was backfilled. The trench between the tower and trailer was dug out. The ramp has a good sized amount of tumble weeds in residence.
– Dave Molter
I arrived at Sugar City at 9 AM and met with Dave about 10:30. We went to Sugar City contact’s (Sue) house and proceeded to disassemble the 10ft Fiber glass satellite antenna and mount in the back yard. This took about 3 1/2 hours and we didn’t complete digging up the concrete foundation but got a good start on it. This will be completed and the dish will be transported in a future trip. Sue gave us contacts for a 10 ft mesh dish in Sugar City and for her daughter’s perforated dish in Rocky Ford. Dave made contacts for 2 more fiberglass dishes in Sugar City. Seems we can have all of these that we want for the asking and labor.
We didn’t get to the Plishner site until about 3:00 on Sunday and by then the previous crew of Aaron Reid, Steve Plock, Gary Agranat, Paul Berge and others had left the facility.
Dave and I set up to determine the cause and fix for the elevation encoder noise that we have been fighting for the last five months. We took a methodical trouble shooting approach with scope and meter instrumentation. We verified that the elevation encoder circuit was much more susceptible to the motor controller noise than the azimuth encoder circuit. It was even susceptible to the Azimuth motor drive but to a lesser degree than to the elevation drive. After trying several things we discovered by continuity checking that the Azimuth encoder wiring shield was grounded to the telescope structure at the encoder end but the elevation encoder wiring shield was open. We opened the elevation encoder box in the upper deck and attached the shield drain wire to the chassis ground with a clip lead. This had a dramatic effect on the noise as seen by the scope and the 12 bit LEDs indicating the input signal state on system 1. Seeing this, we permanently attached the shield drain wire to Pin “S” (Case GND) of the encoder connector and to the attachment screw on the encoder with a flying lead. This substantially reduced the motor drive noise problem on the elevation encoder circuit and should provide much cleaner encoder signals to both system 1 and 2. Of note: There is still a lot of HF noise on the system 1 electronics as indicated on the scope. It appears to be from the small switch mode power supply in the box and the motor drives. It may be wise to change out the small PS with one that is less noisy. We were unable to check the Laptop program operation with System 1 due to a missing password.
We saw the trench that Aaron Reid had dug for the syncro cabling. Thanks to Aaron for that. I brought down a 350 foot spool of 15 conductor x 18awg wire for the syncro connection. Unfortunately we had no suitable conduit to install in the trench so we will have to do that on a separate trip. I left the spool of wire in the locked pedestal for when it can be installed. The deal with OEM Electronics is to use what we need and return the rest for credit as soon as possible. The approximately 160 ft of wire needed will be charged to Michael Lowe’s OEM credit that he established several years ago.
Two curious boys from Los Animus HS stopped by while we were working in the pedestal and we told them about the Dish, but not knowing them didn’t offer a tour. Bill took their names and Email addresses for future contact.
Several spools of RG59u and a 4KW generator were left in the open after the clean out of the RR shed to be used for the outhouse. We moved the wire to the locked pedestal and Dave took the generator back to Springs to see if he could get it running. We put food in the bunker away, locked up the site and left about 7:30PM.
This is Skip Crilly’s presentation for his talk this month at the Society of Amateur Radio Astronomers Annual Conference in Greenbank, West Virginia. The talk is an update of earlier presentations about Skip’s work establishing joint observations by the DSES Plishner 60-foot antenna in Haswell, CO and the 40 foot antenna dish at the Greenbank Observatory in West Virginia.
Also attending this conference from DSES are Dr. Rich Russel and Ray Uberecken.
Dr. Russel will be presenting two papers at the conference:
– “Galactic Navigation Position Data Using Interstellar Medium HI Velocity Measurements”
– “Earth’s Orbital Position Using Galactic HI Interstellar Medium Velocity Measurements”