Installing the 1296 MHz feed for Autumn Moon Bounce Communications

Text and photos by Gary Agranat.

A DSES team worked at the Plishner Radio Telescope site in Haswell on Sunday September 27, 2o2o. Team members were Ray Uberecken, Floyd Glick, and Gary Agranat. We accomplished the main objective, to install a new 1296 MHz feed at the focus of the 60 dish antenna. We also installed a mast in the ground, on which will later be added a Hughes Internet satellite antenna. Two friends of Ray’s came out and did an immense service by using metal detectors and magnetic rollers to clear nails and other metallic debris on the site. We changed out two of the locks. And we inspected the bunker.

Mast for Hughes Internet antenna

Ray and I met at the Plishner site at 0930 in the morning. 

We first installed a sturdy pipe mast behind the operations trailer, on which will be mounted a small satellite antenna to access the Hughes network geosynchronous satellite for Internet access.  Ray chose a spot that will not be blocked by the trailer or the 60-foot antenna.  We mixed cement and set the pole in its hole with the cement, using a level to check that the mast is vertical.

Moon Bounce (EME) Preparation

After that we manually rotated the 60-foot dish antenna to the service platform. I figured out, with Ray’s help and the checklists, how to use the software to monitor the antenna pointing. (Note: we might want to add a checklist just for this type of procedure, for using the software for just manual antenna pointing, as when we service the antenna.)

Floyd came out to the site by 1030. Ray and Floyd climbed the service platform. I worked on the ground to move feeds and tools up and down to them. We replaced the 408 MHz feed at the antenna focus with the newly built 1296 MHz feed. The 1296 MHz feed was built by KL6M, to specifications provided by Steve Plock (KL7IZW). The feed mount at the dish focus was designed by Ray, to enable the feed to more easily rotate out and be changed.

Conditions were somewhat windy, with a cold front coming, but still manageable. By the afternoon the winds had picked up enough that we postponed any further work at the feed. Work that still needs completion is installation of a 200 Watt amplifier at the feed. Since we are planning to operate at 1296 MHz from the Operations Trailer, which has a long coax hard line path to the pedestal and antenna feed, we expect significant power loss from the long path. We therefore need to boost the power again at the feed. We plan to install the amplifier the next weekend. We then also intend to test our setup by trying tropospheric scatter communications to the north.

We are planning to use this configuration to operate EME (Earth Moon Earth) Moon Bounce communications. And specifically we plan to participate in the ARRL EME contests on October 10-11, 2020 and on November 28-29, 2020 (UTC).

We discussed our plans for the upcoming contest in 2 weekends. The Moon then will be at last quarter phase. What that means is that it will rise on Friday night a little before midnight (about 1130 PM), and set Saturday a little after 2 PM. That means we will prepare to do overnight and morning operations. After the Moon rises we will try to pick up the ON0EME beacon in Belgium. We can try to contact across the Atlantic Ocean. The US East Coast will be in night time conditions, and so we anticipate less contacts to there. Daytime conditions, when more hams would be awake, are more favorable for the US West Coast, and across the Pacific Ocean to Oceana, Asia, and Australia.

Note that the 60-foot antenna will be configured with the 1296 MHz feed through the end of November. This will be an opportunity to try using it for other 1296 MHz communications, including troposphere scatter.  

Metal souring of the site

A friend of Ray’s who works at Planet Granite Ryan, and his brother, Rob, came out to the site also.  They have ground metal detectors and magnets on rollers, and systematically paced across the site to pick up nails and other small metallic debris.  They did pick up lots of nails, including along the roadway. They spent a few hours with us, and left after lunch. They did us a great service by helping remove a lot of this debris.

Combination Lock and Bunker Inspection

We attempted to open the combination locks at the gate, the bunker, and the generator shack. After still having difficulty, we replaced the locks at the gate and bunker, with the locks Myron Babcock obtained for us. These are similar model locks, and the combinations were kept the same.

We had a report that the bunker had been flooded by two successive rain storms in July. We opened and inspected the bunker. The bunker was dry, though the floor had more-than-normal dust and dirt, and some tiny debris was spread here and there. It will require a fresh cleanup before normal use. We saw no indication of mold from dampness.

Tumbleweeds were accumulated again at the ramp entrance.

We completed our activities by early afternoon, about 3 PM.

For the team, – Gary

We kept the antenna steering in manual configuration. We opened the System 1 steering software to monitor the position angles as we manually steered the antenna to the service platform.
We noted this radio interference at the site on our scope. This scan is from 0 to 1.8 GHz. The higher floor noise level at the left is from the sensitivity of our 408 MHz feed, which was still on the dish antenna, before we changed it out.
The 60-foot antenna is positioned for service.
Ray brought two feeds for the 60-foot antenna. This is Ray showing Floyd the 4 GHz feed, which we will use in the future, to calibrate the pointing position with geosynchronous satellites.
Floyd carrying the 1296 MHz feed to the antenna for installation.
The inside of the 1296 MHz feed. It is designed as a septum feed, with separate channels on each side for left and right circular polarization.
Rob with a metal detector, crisscrossing the site, picking up small metal debris.
Ray and Floyd on the 60-foot antenna service platform, starting work.
Removing the cover.
Ray is disconnecting the 408 MHz feed, so that it can rotate down and out for changeout.
The 408 MHz feed is now rotated down. It is connected simply by the shaft to the mount, for easier changeout.
Installing now the 1296 MHz feed. Its design doesn’t use a shaft, but instead will be securely fastened to the mounting frame.
Ryan using a metal detector on the west side of the site.
Our view towards the west. High clouds in the distance are an indication of a cold front gradually coming this way. We experienced steady windy conditions as the front approached..
Closing up.
Our view of Haswell in the distance. The clouds from the front were getting closer. By the time we left in mid-afternoon, the clouds were over us, but we had no precipitation.
The 1296 MHz feed installed.
We installed this ground mast. It will mount a small satellite antenna, to connect to the Hughes Internet network.