R: [R-390] Whazzat? Mystery Antenna in San Jose, CA

[paolo gramigna]

It seems to me the antenna of the EAD (automatic direction finder) of the
airport. It works on the aeronautic frequencies. The antennas in the ring of
orange balls are switched electronically, thus creating a doppler effect
that indicated the direction of the incoming signal. The central whip is
used as a reference source, for the purpose of eliminating ambiguity between
the two possible directions of the max doppler.

Cheers,
Paolo