[amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some calculations)

Miguel A. Vallejo ea4eoz at yahoo.es
Fri May 7 16:14:35 PDT 2010

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.


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.


Best Regards,
73, de Pat Barthelow AA6EG; Echoes of Apollo/Arecibo
Arecibo  Video Tours:



"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

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