Rotating antennas
 

What are the rotating dipoles I see here and there used for? I
suspect data but why not microwave? Among others, I see one on
the front of my supermarket, and four more on a pair of large
high advertising signs. I'm sure there are others if I'd look for
them. They are not very noticable.

They are about 4 - 6' long, metal, and turn about once every 5
seconds.

Any guesses?

Just curious.

--
Untie the two knots to email me

Ken Knecht wrote:
What are the rotating dipoles I see here and there used for? I
suspect data but why not microwave? Among others, I see one on
the front of my supermarket, and four more on a pair of large
high advertising signs. I'm sure there are others if I'd look for
them. They are not very noticable.

They are about 4 - 6' long, metal, and turn about once every 5
seconds.

Got an image you could mail me? The address is good.

--
It typically takes 25-30 gallons of petrol/diesel to fully-consume an
average-sized body under ideal conditions. That I am conversant with
this level of detail should serve as an indication of why the wise man
does not ask me questions about MS-Windows. --Tanuki the Raccoon-dog

On Sun, 9 May 2004 19:29:38 +0000 (UTC), (Mike
Andrews) wrote:

Ken Knecht wrote:
What are the rotating dipoles I see here and there used for? I
suspect data but why not microwave? Among others, I see one on
the front of my supermarket, and four more on a pair of large
high advertising signs. I'm sure there are others if I'd look for
them. They are not very noticable.

They are about 4 - 6' long, metal, and turn about once every 5
seconds.

Got an image you could mail me? The address is good.


The ones on top of billboards keep birds from perching atop the sign
and leaving their deposits on the advertisement. I suspect the one on
the front of the supermarket keeps the birds from deposting on
customers.

Ken Knecht wrote:
What are the rotating dipoles I see here and there used for? I
suspect data but why not microwave? Among others, I see one on
the front of my supermarket, and four more on a pair of large
high advertising signs. I'm sure there are others if I'd look for
them. They are not very noticable.

They are about 4 - 6' long, metal, and turn about once every 5
seconds.

If they were on a ship or a naval shore installation, I'd say they sound
like ship radar antennas. But there's certainly no need for a ship
radar on a supermarket! So I suppose the "it scares away the birds"
explanation makes the most sense from here...
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

"Howard" wrote in message
...

The ones on top of billboards keep birds from perching atop the sign
and leaving their deposits on the advertisement. I suspect the one on
the front of the supermarket keeps the birds from deposting on
customers.

So much for the black helicopter theory.

"PM"

Howard wrote in
:

On Sun, 9 May 2004 19:29:38 +0000 (UTC),
(Mike Andrews) wrote:

Ken Knecht wrote:
What are the rotating dipoles I see here and there used
for? I suspect data but why not microwave? Among others, I
see one on the front of my supermarket, and four more on a
pair of large high advertising signs. I'm sure there are
others if I'd look for them. They are not very noticable.

They are about 4 - 6' long, metal, and turn about once
every 5 seconds.

Got an image you could mail me? The address is good.


The ones on top of billboards keep birds from perching atop
the sign and leaving their deposits on the advertisement. I
suspect the one on the front of the supermarket keeps the
birds from deposting on customers.

So logical! Never thought of that! Wonder what made me think they
were antennas? One-track mind.

Ken



--
Untie the two knots to email me

Wonder what made me think they
were antennas? One-track mind.

Just shows your mind is in the right place Ken. ;-)

~^Monitoring The Spectrum^~
Hammarlund HQ129X /Heathkit Q Multiplier
Hammarlund HQ140X
Multiple GE P-780's(GREAT BCB Radios)
RCA Victor *Strato- World*
RCA Victor RJC77W-K(Walnut Grain)
1942 Zenith Wave Magnet 6G 601M
Cathedral/ Ross#2311/Rhapsody-MultiBand
DX100/394/*SUPER*398/399/402
OMGS Transistor Eight/Realistic 12-1451
Henry Kloss Model One/Bell+Howell
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Alpha Delta DX Sloper 57ft.
500ft. 12AWG. (non-terminated)
120ft. 12 AWG Sloper
2 Radio Shack Loop Antennas
Radio Shack Amplified Antenna
30X30 DiamondLoop(six section 830pf Cap)
* Diamond Loop mounted to Lazy Susan TurnTable*
*21/2X2ft.FiveSpoked~Penta-Loop~PancakeLoop*

In article ,
Ken Knecht wrote:

Howard wrote in
:

On Sun, 9 May 2004 19:29:38 +0000 (UTC),
(Mike Andrews) wrote:

Ken Knecht wrote:
What are the rotating dipoles I see here and there used
for? I suspect data but why not microwave? Among others, I
see one on the front of my supermarket, and four more on a
pair of large high advertising signs. I'm sure there are
others if I'd look for them. They are not very noticable.

They are about 4 - 6' long, metal, and turn about once
every 5 seconds.

Got an image you could mail me? The address is good.


The ones on top of billboards keep birds from perching atop
the sign and leaving their deposits on the advertisement. I
suspect the one on the front of the supermarket keeps the
birds from deposting on customers.

So logical! Never thought of that! Wonder what made me think they
were antennas? One-track mind.

Yeah you are a radio hobbyist. Good thing you are not a hammer because
then everything would look like a nail.

--
Telamon
Ventura, California

The ones on top of billboards keep birds from perching atop the sign
and leaving their deposits on the advertisement. I suspect the one on
the front of the supermarket keeps the birds from deposting on
customers.


nah. they're "rotating dipoles" so they're merry-go-rounds for the birds. ;)

I don't know what they're for. I have absolutely no idea what they're for. But
I'm going to guess that maybe they're for security cameras.

maybe there's security cameras mounted inside them, and the rotation is to
allow the security cameras to see a full 360 degree view as it turns around.
and the dipoles are the radio transmitting antennas to transmit the security
cameras' pictures to the stores (or to wherever the ones on the freeways
transmit to, probably to the police station).

Once again, these are all my guesses and I have absolutely no idea what I'm
talking about here.