On Thursday, April 22, 2021 at 12:25:49 AM UTC-5, Matt Herron Jr. wrote:
Hi Darryl,

Here is a link to the pix. Sadly they are TIFFs: https://www.dropbox.com/sh/dhe9415hd...5VFoQ9eMa?dl=0
Yes, I am talking FLARM A, and B. ADS-B is dead center up high under the glare shield and seems to be working fine. you can find a recent FAA report there as well.

Matt
On Wednesday, April 21, 2021 at 3:20:17 PM UTC-7, Darryl Ramm wrote:
On Tuesday, April 20, 2021 at 10:28:54 AM UTC-7, Matt Herron Jr. wrote:
Hi guys,

I just installed a FLARM Fusion and am getting some very poor results.. The antennas are installed symmetrically on either side of the canopy rail (see photographs) in an ASW27b. They clip into a plastic adaptor printed from ABS, and each antenna has a clear 180 degree view out the side of the canopy. This seems to me like a pretty ideal setup to avoid the carbon in the cockpit, etc. Can anyone help me understand why the range is not better, and in particular, why the range is better on one antenna vs the other? that makes no sense to me.

Thanks,

Matt Herron


PastedGraphic-4.tiff

PastedGraphic-1.tiff

PastedGraphic-2.tiff
You can't past images to Google groups, or USENET like this. Can you share the image somewhere, like Google Drive and provide a link to them (and in jpg not TIFF?).

And to be clear you are talking FLARM A and FLARM B antennas? Where is your 1090 MHz antenna?
Matt,

I'm looking at picture 2 and have a couple of concerns:
-The antenna is not shown in the mounting bracket, but from picture 3 it seems certain that the lower arm would be very close and probably touching the fiberglass frame of the canopy. The upper arm is very likely close or touching the canopy itself.
-If the canopy frame is carbon, mounting so close would definitely affect performance, probably severely.

Even though the plexiglass or polycarbonate canopy is not conducting, they both have a higher dielectric constant than air and will definitely affect the tuning of the antenna. Most likely tuning it to a lower frequency than intended. The suggestion to use a wood mounting block to space the antenna away from the mounting surface is a good idea. I'd suggest trying to move it somewhere where there is at least an inch or two air around the antenna (especially the ends of the arms, the mounting bracket is OK as long as it is only near the middle).

I can't say for sure this will fix your problem. The RF design of these systems assume a considerable amount of attenuation from things like this, but if there is too much attenuation you will definitely see unacceptable range. I would also check the cable for crimps and loose SMA connectors.

Rich L.