Friday, April 23, 2021

Cheap and Easy ADS-B Antenna

 This is right from "The Books". It's a simple quarter-wave, ground-plane vertical antenna. Nothing magic, and all it costs is a connector, adapter if you need it, and some 12~14 ga wire.

I started with a female, chassis-mount, Type-N connector, and five pieces of 14ga wire, each 3" long.

After I cleaned the wire, I soldered one of the pieces into the center conductor of the connector for my "Driven Element".

Then I tinned one end of the other four pieces of wire, tinned the corners of the connector, and soldered my ground radials to the connector.

Using a handy reference, I then bent the grounds radials down to a 45* angle.

Now all I have to do is trim the lengths.


Using the "1/4 Wavelength" formula of L=234/F, we get L=234/1090, which equals .21467 feet, times 12, equals 2.576" for the vertical element, and the same for the radials.

All "Trimmed To Length"....

Since the receiver has an SMA type connector, I needed an adapter to screw the antenna onto the radio....


And here it is, installed on the radio. As a bonus, it's easier to hang on the blinds!


So how does it work? I'm still having some issues getting the data from the dump1090 program to properly display on the map, but from looking at the data output in a terminal window, it shows LOTS more traffic than the Diamond SRH77CA dual-band VHF/UHF "Receives Through 900MHz" antenna I was using.


 Now to figure out why in blazes the data won't display on the map......







6 comments:

  1. That's exactly the first homebrew antenna I made for my 2-meter AM Gonset 2 Communicator scaled the 7.5 times for 146mHz though. That was probably in 1958 or so.

    Good luck with the data display.

    ReplyDelete
    Replies
    1. Yep, I made one, too, but used an SO-239. It's like 19" on 2M, and 2" here!

      Delete
  2. Interesting, and odd that nothing is displaying!

    ReplyDelete
    Replies
    1. The antenna works as expected, but I must have messed up something with the installation, or missed a setting I have to change.

      Delete
  3. I don't know what this means but I respect it!

    ReplyDelete
    Replies
    1. It means I can now receive and decode the signals better, but still haven't figured out how to get the info to display on the map.

      Delete

Keep it civil, please....