Hi All,
I have received an email from Daniel Esteban LU2DDU informing me that about the Arecibo radiotelescope he was in touch with Victor KP4PQ in order to get from him more details about the feed line running from the operating site up to the feed.
Victor says to Daniel that for 432.045 MHz they were using an existing wave guide with the larger side 23" high ( 58 cm ) and 1500 ' long ( about 457 meters long) with a loss of 1 to 1.2 dB i.e. about 1.32 time in power ratio at 432 MHz
Please note that the size of the above wave guide can be compared to the air duct of an air conditioning system normally used into a big industrial shed.
Considering that the power amplifier was running at best 350 watt it follows that the power reaching the feed was 350 / 1.32 = 265 watt
Since the gain of the Arecibo dish is 60 dB or 1000000 time in power ratio it follows that the Arecibo EIRP was 265 MW
Tanks to Daniel LU2DDU and Victor KP4PQ for the above information.
Best 73" de
i8CVS Domenico
i8cvs wrote:
Hi All,
I have received an email from Daniel Esteban LU2DDU informing me that about the Arecibo radiotelescope he was in touch with Victor KP4PQ in order to get from him more details about the feed line running from the operating site up to the feed.
Victor says to Daniel that for 432.045 MHz they were using an existing wave guide with the larger side 23" high ( 58 cm ) and 1500 ' long ( about 457 meters long) with a loss of 1 to 1.2 dB i.e. about 1.32 time in power ratio at 432 MHz
Please note that the size of the above wave guide can be compared to the air duct of an air conditioning system normally used into a big industrial shed.
For those interested to see that waveguide, see this message posted in the moon-net reflector some time ago.
Enjoy!
Miguel A. Vallejo, EA4EOZ
======================================================================== Hello Jim, and all,
I have begun assembling my large photo collection at Arecibo taken the last week/EOA event Weekend at Arecibo.
Assembled here are some photos focusing on the Arecibo 432 Feed, coax, to Waveguide transition, and waveguide running the approximately 1500 ft to the line feed "stinger" feed antenna that brings the line image formed by the main circular surface to a point source. The "stinger" line array feed is about 100 ft long from base to tip.
I think Jim Breakall and Joe, were thinking along the lines of .7 to 1 db total loss in the waveguide.
http://cid-2eb5c45df634a712.skydrive.live.com/browse.aspx/ARECIBO%20432%20FE...
Best Regards, 73, de Pat Barthelow AA6EG; Echoes of Apollo/Arecibo Arecibo Video Tours:
http://www.youtube.com/watch?v=vicxDnn6LEY
http://www.youtube.com/watch?v=7rFeXsVz8hE&NR=1
"The most exciting phrase to hear in Science, the one that heralds new discoveries, is not "Eureka, I have found it!" but:"That's funny..." ----Isaac Asimov
participants (2)
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i8cvs -
Miguel A. Vallejo