flarm antenna placement

[Matt Herron Jr.]

Still looking to improve my flarm range especially below. I have a Trig T22 fin antenna on the bottom of my 27. Can I somehow incorporate the receive only flarm antenna into this fin? Too close to the transponder?

RF engineers speak up!

Thanks, Matt

[JS[_5_]]

On Friday, July 13, 2018 at 4:42:56 PM UTC-7, Matt Herron Jr. wrote:
> Still looking to improve my flarm range especially below. I have a Trig T22 fin antenna on the bottom of my 27. Can I somehow incorporate the receive only flarm antenna into this fin? Too close to the transponder?
>
> RF engineers speak up!
>
> Thanks, Matt

I'm not an engineer, but have dealt with enough low-powered RF around the World to suggest... Don't do it.
Is your 27 a B model? If not the FLARM and PCAS antennas can go forward of the rudder pedals on the sides of the nose. Peter Kelley published the installation for his 26 and I used that location in 27058.
Jim

[JS[_5_]]

https://www.valleysoaring.net/flight-ops/power-flarm/
By Peter - sorry for the previous typo - Kelly.
Jim

[Steve Koerner]

On Friday, July 13, 2018 at 4:42:56 PM UTC-7, Matt Herron Jr. wrote:
> Still looking to improve my flarm range especially below. I have a Trig T22 fin antenna on the bottom of my 27. Can I somehow incorporate the receive only flarm antenna into this fin? Too close to the transponder?
>
> RF engineers speak up!
>
> Thanks, Matt

Matt -
There's no practical way to combine them. In fact, any added flarm antenna should not be placed too close to the Trig antenna.

Personally, I don't worry about the detection below that I've heard other people express concern about. All you really need is a few hundred feet of range below for practical collision avoidance. Even an antenna that you'd think of as pretty well blocked downward, will almost certainly give you sufficient functional range below.