This photo shows the ring of waveguide horn feeds
at the secondary focus near the vertex of a VLA antenna.
The active feed is selected by repointing the Cassegrain subreflector.
Since the subreflector subtends a small solid angle at the vertex,
the feed horns must have narrow beams and hence be many wavelengths across.
The largest horn on the right is for L band, 1 to 2 GHz (15 cm 30 cm).
Larger feeds are not practical,
so only prime-focus feeds are used at lower frequencies.
Photo by J. Condon.
Radiotelescope | |
Outstanding antennas : 26-08-2013
Radiotélescope millimétrique Ø=15m
Plateau de Bure Devoluy 05
Radiotelescope | |
Outstanding antennas : 21-11-2013
Joderell bank - UK
Outstanding antennas : 05-01-2014
Stockert, near Bad Münster Eifel - DL
Outstanding antennas : 13-01-2014
South Pole 90°S
l'antenne de gauche est assez intéressante,
sa polarisation tourne de 360° en 24heures sans rien faire !
l'antenne de gauche est assez intéressante,
sa polarisation tourne de 360° en 24heures sans rien faire !
Outstanding antennas : 31-01-2014
Antennes ESO Alma Chili en test en EU
!
!
Outstanding antennas : 16-02-2014
Antennes ESO Alma Chili
Jolie cordée de 21, mais avant de les mettre en phase il reste du boulot !
Jolie cordée de 21, mais avant de les mettre en phase il reste du boulot !
Outstanding antennas : 18-12-2014
SRT Sardinia Radio Telescope 39.492707,9.244184
Outstanding antennas : 01-08-2015
Outstanding antennas : 27-07-2015
EISCAT Svalbard JW
Outstanding antennas : 15-06-2015
Outstanding antennas : 26-05-2015
Alma - Thales Alenia Space
Outstanding antennas : 21-03-2015
SKA - Un radio téléscope géant réparti entre ZS, VK & ZL
Outstanding antennas : 13-03-2015
Radio Astronomy at Dover Heights VK - 1952
Outstanding antennas : 22-11-2014
Lego contest
Outstanding antennas : 17-10-2014
ESO @] San Pedro de Atacama Chile
Radome souple télescopique en 2 quarts de sphère
Outstanding antennas : 02-10-2014
Staring Horn @ Green Bank WV
Outstanding antennas : 16-06-2014
Sourcing : tks F5BQP
Outstanding antennas : 03-11-2013
KP4AO Arecibo Observatory on the air ( Ø = 305m )
10 November from 14 UTC to 20 UTC to celebrate the observatory's 50th anniversary.
10 November from 14 UTC to 20 UTC to celebrate the observatory's 50th anniversary.
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WWII Radar
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Phased Array Radar
Radar Marine
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OTHR Radar
Radar
Track Sat.
Pixel mania | |
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Inside Radome
Outstanding
Antennas
Chapter 2
WX Radar
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Pixel mania | |
AO-Journal |  |
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Updates
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Outstanding
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Chapter 2
