FlightAware Discussions

Coverage dropped after shortening cable

Hi All,

I have a FlightAware Pro Stick Plus connected to the flightaware antenna in my loft. I was using a 5m cable to connect it to my pi. After seeing some comments about having as shorter cable as possible I got an adapter so I could plug the FlightAware Pro Stick Plus directly to the antenna without any cable in the loft. My coverages has gone from 200NM to under 100NM!

Should it have improved my range, is it possible I have a bad connector or is what I have done a bad idea?

What gain are you using.
You need to set the gain down, probably its now overloaded on signals.

Just defaults I guess, I’m really new to this. How do I turn the gain down? What should I set it to?

That depends on what system you are using.
If you are using the flightaware system you can edit with SSH or remove your SD card and edit the file /etc/default/dump1090-fa
Probably you have the gain at -10, and that could be to much.

The best tip I can give you is to install GitHub - wiedehopf/graphs1090: Graphs for dump1090 (based on dump1090-tools by mutability) from @wiedehopf
So you can get a better view on your signals.

Here is my signal, you can see pre and post move
image

That has way to much gain.

Ok i would try to set the gain at 44.5 and then go downward in steps
(33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6)

Just use SSH or edit the SD card on your PC.
Use this file /etc/default/dump1090-fa

Probably you have interference … without the coax attenuating it a bit it completely drowns out the LNA.

You’ll need a filter … or for the moment just go back to the coax.

Something like this? FlightAware 1090 MHz ADS-B Bandpass SMA Filter– The Pi Hut
I thought the FlightAware Pro Stick Plus had a filter built in.

Is there likely to be a measurable range or coverage benefit of my project to eliminate the cable?

Yes, exactly this one.

Yes it has, but it is located after LNA chip, so the RF interference already overloads LNA chip before it is filtered out.

Thank you everyone, I will put one on order.

Please brows this post and see the 3 scan plots which clearly show the effect of adding filter.

Please note that benefit of adding a filter depends on location, as each location has a different degree and different frequency of interference.

Spektrum - How-to Speedily Scan RF Noise in band 24MHz ~ 1800MHz

 

I have purchased the filter and fitted it. The order is FA Antenna, sma converter, filter, FA dongle, Pi Zero with no cable. Prior to this I had put the 5 Meter coax cable back.

image
image

You can see when I installed the filter and removed the coax. I wanted to remove the cable to increase the range, but it seem something is not right.

Any thoughts welcome :slight_smile:

Try filter + coax :slight_smile:

That adapter might just be bad.
Or when you have the RPi close to the antenna interference from the Pi couples back into the antenna?
Hard to say.

Should the filter be connected to the antenna or the dongle?

For Beginners - Howto Connect FlightAware Antenna, Filter and Pro Stick - Connectors and Cables Required

 

Thank you, I have a blue FA dongle. Is it still ok to add the additional filter?