Why are the dishes like this?
I'm in Israel right now, staying in the Armenian quarter of the Old
City of Jerusalem, and I noticed something odd, afaik, about a couple
satellite dishes I see on a couple buildings.
The dishes are about 3 to 4 feet wide, iiac, and there is a rod across
the front that holds an "antenna" in the focal point, I guess, of the
concave dish.
But there are also 2 more antennas, one on the left of center and one
on the right, about 8 to 10 inches away from center. All three are
white boxes about 3 inches x 3 x 4. I can understand why they might
need three antennas, but I don't see how 2 of them can be so far from
the center. Maybe they're not using the other two, just storing them
for when the center one breaks? ??
.
Relevant Pages
- Re: Why are the dishes like this?
... City of Jerusalem, and I noticed something odd, afaik, about a couple ... satellite dishes I see on a couple buildings. ... But there are also 2 more antennas, one on the left of center and one ... about 8 to 10 inches away from center. ...
(sci.electronics.repair) - Re: Why are the dishes like this?
... City of Jerusalem, and I noticed something odd, afaik, about a couple ... satellite dishes I see on a couple buildings. ... But there are also 2 more antennas, one on the left of center and one ... about 8 to 10 inches away from center. ...
(sci.electronics.repair) - Re: Receiver antenna
... | assuming a velocity factor of.8c, ... Yes, but in the case of most antennas, the dielectric is air, so the ... that gives us a value of 39 inches. ... If you calculate the wavelength of a 72 MHz signal in a vacuum, ...
(rec.models.rc.air) - Re: The new domestic aerial regulations;(...
... The current planning regulations for satellite dishes and other antennas are inadequate in that there are different regulations for each type of technology. ... And ignoring the wavelengths and power flux densities of the signals, directional discrimination requirements, path profiles and just about any other technical consideration you can think of that requires different shapes, sizes and placing of antennas for the different platforms. ...
(uk.tech.digital-tv) - Re: And yet an even more radical proposal.
... RC> that come with the satellite dishes can even detect frequencies ... RC> the wavelengths that the .5 m antennas could usefully collect, ... wavelengths across, or diffraction starts to become really important. ... Thus, for instance, the VLA (25 meter diameter), when operated at 74 ...
(sci.astro) |
|
