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Old August 28th 19, 04:35 PM posted to rec.aviation.soaring
Dan Daly[_2_]
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Default "Do It Yourself" airborne proximity warning device

On Wednesday, August 28, 2019 at 8:59:02 AM UTC-4, wrote:
On Tuesday, August 27, 2019 at 5:43:55 PM UTC-5, Dan Daly wrote:
You can download the FCC and IC testing report for the PowerFLARM CORE/Brick, pictures, etc. at https://apps.fcc.gov/oetcf/eas/repor...id=ZKUGC625162

They are thorough.


Thanks for the link. Now I know what the inside of a Flarm looks like.

I wonder why they didn't test with both antennas active. If I read the test report correctly, their radiated power (33mW) is way lower than the inteference limit (1W), so it seems like it would have passed easily.

There was another limit around 60mW for something?


The 1W limit is designed for devices on the ground. Since your large Line of Sight range at altitude makes it much more likely that you will interfere with someone else - so they reduce the power - your reach is much greater.. We 'see' PowerFLARM CORE/Bricks at about 120 km with radiated power of 0..018W on our OGN system. If you boost the power, and there are a lot of gliders/towplanes fitted (we have around 40 in my area, increasing by the day), the chances of mutual interference increases. And, the Industrial, Scientific, and Medical (ISM) 902-928 MHz band is pretty busy.

Here's the LXNAV report link https://apps.fcc.gov/oetcf/eas/repor...d=2ASPHLXNAVAM
Looks like it radiates 0.07W...