co-phasing 102 inch whip antennas

[thefifthseal]

I want to co-phase 2 102 inch whip antennas for my base station?
Can anyone tell me how I can do the set up?

 

[Marconi]

Sorry guys, the post I made here did not belong. I was referring to 1/4 wave whips and not big outside base station antennas, but if you do use a mobile 1/4 wave antenna then RW is right, you will need a very good ground plane.

 

[RoadWarrior]

Co-Phase 2 A-99 antennas. The mobile whips will not work
good unless you provide a good groundplane under
them (Metal). I take it your mounting them outside.
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http://www.signalengineering.com/ultimate/co_phasing.html

 

[W5LZ]

Hmm. If you're going to that kinda trouble why not add an additional matching section which can be switched in/out of line (to one of the antennas) to change the radiation pattern 90 degrees? How long is that additional matching section? Depends on the kind of switching you can do, remote or not. Just make it an odd multiple of one of the sections going to one antenna.
- 'Doc

 

[RoadWarrior]

Are you going to mount antennas inside your home
or outside???
Marconi your post was OK. I was just sharing other
options he could take.
Straight co-phasing only gets out good in 2 directions. Forward
and backward. Is this what you want???

 

[Marconi]

That is OK Jim, the piece I wrote and posted here did not seem to fit thefifthseal's question. I wrote that piece for another thread and another forum, so I just removed it. The piece was my idea of how to build a co-phase harness and that is not what TFS wanted. I also share your opinion about the other options and the need for a good ground plane with any 1/4 wave radiator.

 

[jonbah]

You can use the 102's by adding a simple counterpoise to each antenna. or mounting them onto a metal roof. This would work ok and still be cheeper than buying a wonder antenna. (Wonder how they get all that gain)
(Wonder why I'm bleeding the TV)
Or you could make a trick stick out of the two 102's
why not.

Jonbah

 

[Moleculo]

Straight co-phasing only gets out good in 2 directions. Forward
and backward. Is this what you want???

That's not exactly correct. The radiation pattern and direction depends on the spacing and timing between antennas. To give instructions on the proper coax lengths and spacing, we would need to know what you were trying to accomplish by cophasing the two antennas.

 

[RoadWarrior]

Yeah, your right Mole.