Yagi for repeater

[Gma79]

Hello all, I was wondering if a yagi 9.2 dbd would suffice for duplex operation? My elevation is 2815 ASL. My antenna elevation is around 68 feet above ground. I plan on using pvc boom to avoid metallic cross interference. What position should i place the yagi, vertical or horizontal, that my system would benefit based on my elevation and horizon?

[AdmiralCochrane]

Half way up a hill and no one behind you?  I don't understand what the practical application of a yagi would be with a repeater??

[mbrun]

Hello all, I was wondering if a yagi 9.2 dbd would suffice for duplex operation? My elevation is 2815 ASL. My antenna elevation is around 68 feet above ground. I plan on using pvc boom to avoid metallic cross interference. What position should i place the yagi, vertical or horizontal, that my system would benefit based on my elevation and horizon?

Not knowing what it is you’re trying to achieve it is hard to say.

 

There are cases where some form of directionality may be desired, but I suspect those are few and far between.

 

Generally speaking, repeaters are positioned towards the center of their intended coverage area. A Yagi in that environment would be counter productive. However, if your repeater is located along a coast line or the edge of your desired coverage area you may favor directional antenna to maximum power into your target area. I would speculate however that there are few cases where a highly directional Yagi is the appropriate solution.

 

Conversely, I can definitely see where a Yagi could benefit the distant base station trying to hit a distant repeater.

 

Now, a collinear antenna with high gain is different story. With a collinear design you can achieve high gain and uniform horizontal (azimuth) coverage all around then antenna. I believe you will find some variant of the collinear design to be the most common for high-performing repeater sites.

 

Michael

WRHS965

KE8PLM

 

Edited for spelling.

 

Sent from my iPad using Tapatalk

[berkinet]

...What position should i place the yagi, vertical or horizontal, that my system would benefit based on my elevation and horizon?

 

As to the question of a yogi vs. some other design of directional antenna, or even directional vs. omni-directional, it is impossible to answer without knowing more about what you are trying to achieve and the specific terrain.

 

However, what I can tell you is that it is virtually certain you will want whatever antenna you use to be vertically polarized. The only exception would be if you were doing some type of fixed point-to-point linking where you needed some propagation effect that was better supported by horizontal polarization.  But, assuming you will be serving a mix of mobile, portable and fixed stations, you want vertical.

[1URFE57]

I remember before I saw a 4 stack yagi for TX and a Diamond GP on top of it as a RX antenna it was Bus company's repeater back in the Philippines so it's doable but has limitation and extra $$$$.