Like all DSN 70-m antennas, DSS-14 has a tri-cone feed arrangement. Two cones have the DSN S-band and X-band telecommunications transmitters and receivers. One of these cones has an angled mirror which reflects S-band and passes X-band. The cone with the large solid mirror has the S-band systems.
The third cone has the Goldstone Solar System Radar X-band transmitter and receiver and a dual-feed K-band receiver. In the figure below, the person is holding a microwave absorbing target over the K-band horns.
All the feeds are on a ring centered on the antenna's mechanical axis. The subreflector rotates so as to put the optical focus on a selected feed. (By virtue of the two reflectors, the S-band and X-band systems effectively share the same focus position at rotation angle 240°. At the rotation angle for each horn there is a pin that can be inserted to hold the subreflector rotation at that angle. The 'pinned' angles are
| Pin | Feed |
|---|---|
| 000 | GSSR Transmit |
| 009 | Ka-Band Holography |
| 024 | K-Band |
| 120 | X-Band |
| 240 | S-Band |
| 300 | L-Band |
| 336 | GSSR Receive |
The DSS-14 K-band feeds are symmetrically positioned about the K-band 'pin'
rotation angle.
The separation of the beams on the sky is about 0.032°, a little more than
two half-power beamwidths. The plot below shows the beamshapes when the
subreflector is at the 'pin position.
The next one shows the beamshapes
for the two feeds when the subreflector is at 023.084°.
For K-band and other precision pointing needs, the antenna is servoed to a redundant master equatorial. For less exact pointing needs, the antenna is driven under computer control from azimuth and elevation axis encoders. Each mode and each receiver position has its associated pointing correction model.
Chapter 5 of "Large Antennas of the Deep Space Network" by William A. Imbriale gives a detailed description of the DSS-14 64-m antenna and its upgrade to 70-m, as well as experiments to improve its Ka-band performance.