PING Bill

Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an electrical
connection is obviously made to the pole and teh co-ax feeder connects
at the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide near
ends?

Stephen.

Steve wrote:
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an electrical
connection is obviously made to the pole and teh co-ax feeder connects
at the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide near
ends?

Stephen.
No.

Bill

On 19/08/2013 19:55, Bill Wright wrote:
Steve wrote:
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an
electrical connection is obviously made to the pole and teh co-ax
feeder connects at the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide
near ends?

Stephen.
No.

Bill

Bill, Thank you for your answer but its a little vague as to which part
of my post you're saying no to?

No to having 2 or more LP's on the same metal pole or No, there will be
no interaction between the two LP aerials?

On Mon, 19 Aug 2013 20:20:48 +0100, Steve
wrote:

On 19/08/2013 19:55, Bill Wright wrote:
Steve wrote:
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an
electrical connection is obviously made to the pole and teh co-ax
feeder connects at the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide
near ends?

Stephen.
No.

Bill

Bill, Thank you for your answer but its a little vague as to which part
of my post you're saying no to?

No to having 2 or more LP's on the same metal pole or No, there will be
no interaction between the two LP aerials?

Our German friends http://www.schwarzbeck.de/Bilder/9128c.jpg

http://www.satcure.co.uk/accs/v10_stealth.htm

http://www.aerialsandtv.com/aerial%2...ialHeightTests

http://www.hellotrade.com/rolf-heine...c-antenna.html

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Steve wrote:
On 19/08/2013 19:55, Bill Wright wrote:
Steve wrote:
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an
electrical connection is obviously made to the pole and teh co-ax
feeder connects at the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide
near ends?

Stephen.
No.

Bill

Bill, Thank you for your answer but its a little vague as to which part
of my post you're saying no to?

No to having 2 or more LP's on the same metal pole or No, there will be
no interaction between the two LP aerials?
You can put as many LPs on the same mast as you like, but keep them
about two foot apart if you can.

Bill

I'd say no as they are in fact shorted here in any case its just a
reflector.
Brian

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From the Sofa of Brian Gaff Reply address is active
"Bill Wright" wrote in message
...
Steve wrote:
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an electrical
connection is obviously made to the pole and teh co-ax feeder connects at
the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide near
ends?

Stephen.
No.

Bill

"Steve" wrote in message
...
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an electrical
connection is obviously made to the pole and teh co-ax feeder connects at
the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide near
ends?

Stephen.

It will be OK as long as they are a few [longest] wavelengths apart.

R. Mark Clayton wrote:
"Steve" wrote in message
...
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an electrical
connection is obviously made to the pole and teh co-ax feeder connects at
the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide near
ends?

Stephen.

It will be OK as long as they are a few [longest] wavelengths apart.


A lot less than that is OK. Two wavelengths on ch21 would be over four foot.

Bill

"Bill Wright" wrote in message
...
R. Mark Clayton wrote:
"Steve" wrote in message
...
Is it OK to have two or more Log periodics on the same aerial pole?

Reason I ask is that at the near end of the log periodic, an electrical
connection is obviously made to the pole and teh co-ax feeder connects
at the tapered pointy end.

So will the two LPs interact via the metal pole coupling their wide near
ends?

Stephen.

It will be OK as long as they are a few [longest] wavelengths apart.
A lot less than that is OK. Two wavelengths on ch21 would be over four
foot.

Bill

OK one wavelength = 63.29cm

In article , R. Mark
Clayton
wrote:

"Bill Wright" wrote in message
...
R. Mark Clayton wrote:
"Steve" wrote in message
...
Is it OK to have two or more Log periodics on the same aerial pole?


It will be OK as long as they are a few [longest] wavelengths apart.
A lot less than that is OK. Two wavelengths on ch21 would be over four
foot.

Bill

OK one wavelength = 63.29cm

This may depend on your definition of 'OK' and the details of the case.

A gain means a given effective area. So higher gain antennas at a common
frequency will need to be spaced further apart if pointing the same way.
Quite how the loss in efficiency changes with spacing will vary with the
details. You can estimate this from

G = 4*pi*Area / (wavelength squared)

and assuming the area is, say, a square. So the spacing scales linearly
with gain.

However if one is in the 'near field' of the other it gets more complicated
as they then work as an array linked by the 'circulating' parts of the
resonant fields around the elements.

So in practice the simplest advice is to follow Bill's experience unless
you want to experiment. :-)

Slainte,

Jim

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