Changing the antenna feed for Moon Bounce

Photos courtesy of Glenn Davis. Text by Bill Miller.

On Friday afternoon October 14, 2022, we prepared the 60-foot dish antenna for the weekend’s Moonbounce communications operations in the ARRL EME contest.

Glen Davis updated the tracking software, checked the callibration of the mount and helped as ground crew and photographer. Meanwhile Ray Uberecken and Bill Miller climbed the scaffold and¬†changed the feed from the 437 Mhz antenna to the 1296Mhz antenna.¬† They also installed Ray’s 180 watt amplifier at the antenna feed point and checked the system reception from Ray’s Calhan residence beacon.

Measurement check of the dish antenna

On Sunday October 2, 2022 Ray Uberecken, Dan Layne and Gary Agranat climbed on to the 60-foot dish antenna to measure the dish diameter, the distance from the dish center to the feed, and the bore alignment. This verified the original geometry specifications continue to be valid to at least within a quarter of an inch.

The original plan for the day was to also install the 1296 MHz feed at the focus, for the upcoming ARRL EME contest. However, the wind gusts increased, as was anticipated from the forecast. The feed changeout was therefore postponed.

Measuring the first leg of the distance from the dish center to height of the edge, using the tape measure suspended from the dish edges.
Ray securing the tape measure to measure the dish diameter.
Dan measuring the dish diameter at the opposite edge.
Antenna focus
Securing the ladder
Scattered rain shafts started to pass during the afternoon.

Photos by Gary Agranat