[evlatests] ea21 at Q-band

[Paul Demorest]

Rick,

ea21 has known strange focus behavior that has never been explained.  The subreflector moves by a much larger distance than it is commanded to.  We have a reasonable focus value in place for moderate elevations but it is likely interacting badly with the "focus vs elevation" correction.

-Paul

________________________________________
From: evlatests <evlatests-bounces at listmgr.nrao.edu> on behalf of Rick Perley via evlatests <evlatests at listmgr.nrao.edu>
Sent: Wednesday, July 9, 2025 4:27 PM
To: evlatests
Subject: [evlatests] ea21 at Q-band

There is something amiss with ea21's performance at Q-band.  The gain curves I've derived from the March 'Flux Densities' run show an enormously large dependance on elevation, especially notable at elevations below ~30 degrees.  The forward power gain at 10 degrees is 1/4 that at 50 degrees.

Other bands look reasonable.

Rick