FlightAware Discussions

Shortening coax feed

My vertical antenna is about 8m + above ground level and is fed with about 28m of Westflex 103.
I am not sure in performance terms what the losses are because of the length of coax.
At the base of the antenna is my “telescope” shed which has power and a wired internet connection.
I have wondered what the advantages would be if I were to house my RPi in the shed and shorten my coax by about 18m. Any comments or advice appreciated.

Westflex 103 has a loss of about 14dB per 100m, about 2.52dB less loss. This equates to approximately doubling the signal strength.

Worth doing unless you are in an area with a high lightning risk.
Ethernet between buildings can be risky. Not a problem if you are connecting to the receiver by WiFi with the router inside your house.

Thanks for your reply. The router is in the house and I wont tempt fate by saying I am not in a high risk lightening area. Next free weekend I will replace the coax feed and let you know how things go.

If WiFi works well enough between your “Man cave” and the house, I would use that.
It’s better not risking frazzling everything on your Ethernet network.

I agree. Just keep the microwave oven as far away as possible, or upgrade the wireless router to 5GHz. :wink:

On second thought, does the RPi supports 5GHz wi-fi? Need to check, the RPi4, perhaps?

The Pi4 runs toasty hot, if you aren’t running something like an AirSpy you probably don’t require one (Unless you are adding to your collection of Pis).

I agree, but I was focusing on the Wi-Fi part.

My garage, where the Pis are, is a fair distance from my study, where the router is. The microwave oven in the kitchen is kind of in between the two. When it’s on, communication between the Pis and the router drops.

Absolutely right.

I use an RPi model 2 for ADS-B which is running perfectly well (no overheating, cpu usage less than 30%) with following:

All following software is running on Single RPi Model2

  • dump1090-mutab-1 (antenna 1, dongle 1)
  • dump1090-mutab-2 (antenna 2, dongle 2)
  • Piaware feeder 1
  • Piaware feeder 2
  • FlightRadar24 feeder 1
  • FlightRadar24 feeder 2
  • Planefinder feeder 1
  • Planefinder feeder 2
  • Adsbexchange feeder 1
  • Adsbexchange feeder 2
  • RadarBox24 feeder
  • OpenSky feeder
  • Planeplotter uploader
  • ModeSMixer2
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Thanks for the informative replies, a litle bit more to consider.

Although it is not as bad as it was at the launch, there have been a lot of improvements on this front on the software side.

That is true, but if you need a Pi4 for ADS-B then additional cooling will almost certainly be de rigueur.

I have a 75 ft piece of lmr-600 that I tried out connecting to the flightaware antenna. I was really impressed with the outcome. Although impressed, my plan is to run the hole thing solar in a box and run ethernet to the router. That being said, there will be minimal coax loss and will be mounted on the tower about 30 ft up. I cant wait to get this going. My solar to usb should be in the mail next week to power the pi.

you can tell where I connected it up for a few hours that day.

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What cable are you using the LMR600 against? That’s some nice results