I received a squeezed-tube depolarizer and super Kumar scalar ring from Paul M0EYT (from uhf-satcom.com). Jason KC2TDS terminated it with a waterjet-cut copper disk and added a probe which he carefully tuned with the VNA to get <20dB return loss in the 8.4 to 8.45GHz DSN band.
My plans for this weekend are to take down the 23cm EME feed from the 3.5m dish and test this feed after taking some measurements with the horn that Jason KC2TDS built based on Michal SQ5KTM’s design.
IMPORTANT UPDATE 1 June 2020: Please see https://www.prutchi.com/2020/06/01/probe-location-for-squeezed-tube-x-band-dsn-feed/ for the correct probe orientation!