[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: "Trash Can" dish antennas



Rick:
We actually call them "trash can" antennas.

They're satellite antennas for the military UHF band.  They are
stabilized to s hips gyro to maintain track on whatever geo synchronous
bird they're aimed at.  No automatic tracking, so you had to adjust
where they were pointed as your position changed.  What they would do,
is automatically compensate for changes in ship's heading, and pitch and
roll.

Was never able to get inside them, my guess is some kind of "splash" or
helical feed.  I know that they worked a bit better than whatever the
heck preceeded them; can't remember what that was -- been too long.

Hope this helps some.
73,
Jim


RMckni8527@aol.com wrote:
> 
> Most larger Navy and USCG ships have "trash can" antennas mounted on the
> flying bridge.  The best way for me to describe them would be to take a metal
> trash can, cut half of the top off, and mount the parabola in the bottom with
> the feed in the open end.  This in effect is like wrapping a "fence" around
> the outside edge of a normal circular dish.  Does this serve to eliminate
> background noise from over illumination of the dish, so the feed only sees
> signals from the front of the focal point?
> 
> I don't know the official nomenclature of these antennas, but they're about
> 4-5 ft in diameter, painted Navy gray, have gyro stabilized tracking, and are
> always seen in pairs one port, one stbd on the flying bridge.  Not sure what
> they're used for.  They do actually look like a trash can, or maybe more
> closely resemble a tub used for icing down a beer keg.
> 
> What are the implications for a dish used on our satellite freqs?  Beneficial
> to explore a similar design?
> 
> 73's
> Ray - WB3ABN
> Kingston, WA
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home