May 11, 2020 DSES Engineering and Operations Meeting Notes

by Bill Miller 5/11/2020

We had 17 participants in the virtual engineering meeting today:  Most ever! Thanks everyone for joining.

Participants: Dr. Rich Russel, Ray Uberecken, Myron Babcock, Ted Cline, Bob Sayers, Jonathan Ayers, Xander Duvall, Tony Bigbee, Ed Corn, Gary Agranat, Skip Crilly Don Latham, Glenn Davis, Floyd Glick, Matt Mathews, Bob Haggart, Bill Miller

Agenda and notes:

  1. Check in. How is everyone doing with the stay at home/safer at home situation.  Is anyone experienced or known someone experiencing the virus? Anything we can do for them?
    • We have had one core member contract and recover from the virus that we know of.
    • We cancelled in person meetings in March and went to virtual meetings to protect members.
  2. Myron’s Treasure’s update:
    • Checking $2440.40 
    • Savings $5741.85
    • Upcoming Insurance $290 to $310 
    • Board to approve reimburse to Steve for New Mexico mileage to set up the Ettus pulsar receiver with Joe Martin.
    • Membership
      1. 30 Voting members including 5 lifers  and 12 nonvoting. Myron checking with others as yet unpaid.
  3. Pulsar detection congratulations to Team and further work from Rich Russel
    • On the attempt on Feb 15th,  the gains were set too high and saturating the Ettus Research SDR receiver. Need to tune this front end gain into proper range for the input of the SDR.
    • Last Week on May 2, B0329 +54 pulsar got it on the fourth try for a ½ hour run with manual tracking.
    • This week on May 9 , got the B0329 +54 pulsar on 420Mhz+/-5 Mhz. which is the  second brightest pulsar and tried three others and didn’t see them.  All the others were low in the horizon. Joe Martin took 12 hours to get one of them at his site but the DSES team didn’t get any of the others yet.
    • Would like to be able to do the Crab Nebula Pulsar. Joe Martin has not gotten that one yet.
  4. Additional engineering needed for pulsar work.
    • Automatic tracking
    • Intermittent a/b switches on the encoders is causing a problem. Rich wants to take them out. Bill says they are not inherently intermittent but dirty.  Ray said that exercising them solved the immediate problem but if taking them out will improve the process, Bill’s OKAY with that.
    • Pulsar software used is Presto. Scott Ransom in Charlottesville is author and Skip can connect you if having issues or feedback.
    • Tony sites “Murmur SW is a predictive program to help set up for Pulsar observation.
    • Ray added 20dB amp in the comm trailer.  Steve has a preamp with better noise figure that can be added at the feed.
    • Each pulsar will take a minimum of about an hour of collection time.
    • Steve and Paul Berge need to reset the electric azimuth drive stops so that the system will track the circumpolar pulsars continuously without wrapping back around. Currently can only go 15 degrees past north and need to be set up for 90 degrees from north.
    • Tropospheric observations need a different stop.
    • Ray says the pulsars observed lately are circumpolar, near the north star so need to be able to go to the 90 degree mark on either side.  Paul Berge could do the adjustment on the limit switches.
    • Manual tracking  is boring and automatic tracking would be better. 
  5. Ray: Feed work and change out capability
    • Ray has another 1420 MHz feed that we would like to try
    • Steve located his electronics box in the same spot where Ray was planning for his box so need to reconcile this positioning with Steve.
    • Ray has a 1296 MHz feed available to do moon bounce and tropospheric scatter work.
    • Ray has installed rotating swivel joints in the coax.
    • The coaxes pull up through the center when moving the elevation to the horizon.  Currently the coax swivels are only a few feet below the tube and one broke when moving the elevation to 90 degrees so Ray will mitigate that with some extra flexible coax.
    • Skip asks about the bandwidth of the 1420 MHz feed.  Skip used 1390 – 1460 Mhz and this is the same specification  of the preamp that Ray used.
  6. SETI project with Skip. 
    • Skip will not be able to go to Greenbank with travel restrictions but will be able to do observation from his New Hampshire observatory. 
    • Skip’s dish is running 24/7 with 6 computers. Doing a lot of post processing of the data he is collecting.
    • Skip says there is no real urgency for simultaneous observations because of this and not to risk anything for his sake at this time.
  7. Tracking System 1 update;
    • System 1. Lewis Putman completed the HW design and will connect with Jones plug in the back of the rack. 
    • The control SW is updated, and Glenn will do some testing and give it to Lewis.
    • Glenn will set up a design review with Lewis, Dave, Bill and Ray to discuss the electrical interface plans.
  8. Summer site work?
    • Bunker bunk room.
    • AC up to feed point needs conduit
    • Water heater in the
    • Two 30 Amp 240 volt outlets in generator shed.
    • Top door for the doghouse. Need steel 32 inch door.
  9. Ham radio
    • Looks good
    • Need some cross bolts in the Yagi beam.
    • Addition antennas?
  10. Eastern SARA August Conference, August 2-5, 2020 Green Bank Observatory WV.
  11. Open House? 
    • Need to wait till late June for a decision on announcement due to uncertainty of the virus situation.
    • Gary and Bill will check for best calendar dates considering the Moon, other events and Ham activities.

Open Floor

  1. Bob Haggart, 
    • The back door of the trailer opened up a little crack and allowed the dirt to blow in.
    • Sealed up the AC units and other openings but must clean out the dirt.
    • The back air conditioner needs replacing. Bill has one he will donate.
    • The Heater was removed to make room for the back workbench
    • Bob working on the battery room as a storage room.  The tower inverter power is running off the railroad batteries in the comm. trailer so Bill doesn’t see any reason to replace the old wet cell batteries in the battery shack and we should recycle them.
  2. Gary Agranat
    • Gary has an upcoming MIT class reunion that has been moved to a virtual reunion. 
    • He has been asked by the class committee to make a class presentation on the Plishner Observatory and what we are doing in a Ted talk format.
    • This will be a great networking and familiarization opportunity with the 1985 MIT class.

Bill recorded the meeting on Zoom. It is in two parts, due to a gap in Internet coverage:

  1. https://www.dropbox.com/sh/1ms0ngdjrrsehhk/AABn9w_NLjV8hEoB9VRas37_a/2020-05-11%20DSES%20Eng%20Meeting%20Zoom%20Part%201.mp4?dl=0
  2. https://www.dropbox.com/sh/1ms0ngdjrrsehhk/AADRvLawoJnZl4RlvW90N6Ora/2020-05-11%20DSES%20Eng%20Meeting%20Zoom%20Part%202.mp4?dl=0