FlightAware Discussions

Three Easy DIY Antennas for Beginners

abcd567 "The one thing I have tried & know is that the 70 mm dia Can gives better result than 55 mm dia Can which gives better results than 25 mm dia Can. "
I found the same, Larger cans performed better but I dont know what the upper limit is ie the sweetspot

Thanks all, so I’ve tried to cut down the coax cable <5cm still bad, I’m starting to think that it could be the connector (pig tale?). Anyways thought I’d give it another go at DIY, based upon the original post on this tread would these be appropriate:

Have you tried just optimizing the whip as in the picture from abcd with the can below the antenna?
That way you don’t need to buy an adapter.

Do NOT cut the whip. Unscrew it, and use a thin wire as whip

If the wire is thin, it will be easy to wrap it over the threaded brass stud of the magnetic base. With thick wire it is a bit difficult.

 

Optimized Whip Steel Tie Wire-461x500

 

UTP-Cable-Picture

 

 

optimized mag-mount 1090Mhz 52 mm-R2

 

:+1: :+1: :+1:

Placing whip antenna over a metallic can or metallic plate is the easiest thing to do, and gives the biggest improvement to the performance.

Added advantage (if plate or can is made of iron/steel) is that it keeps antenna vertical and prevents antenna from falling

Thanks both,
I thought perhaps it might still be worth trying a spider one as I could mount it in a more favourable position, is the DIYed original antenna roughly equivelent to the DIY spider?
If all else fails “fixing” the original by curling wire around can certainly be done (I’d rather not chop the antenna), and atm it is on top of metal surface which has indeed seemed to have helped, despite it not being the optimal length.
I’m assuming them parts look good then? I have both the time and the inclination to mess about with spider just as it’s fun to try make your own!

At the beginning of my feeding experience i’ve also built a very simple spider as shown above. IT was a lot better than the small whip antenna.

Give it a try, doesn’t cost that much

Yeah you’ll need a suitable adapter that actually works.
Then you can do DIY as much as you like :wink:

Just with that adapter you had it didn’t seem to make much sense.

1 Like

Derivative of the spider …

If you have some cheap coax, the insulated center wire can be pulled out easily from the rest of the cable. The size of the soldered loop allows it to fit over a coax connector.

It’s easy to try different length center pieces as the center piece isn’t soldered - the stripped end is just pushed into the coax connector. Having an impedance analyzer makes it easy to fine-tune the length of the center radial and the angle of the ground radials.

I later switched to the SMA-to-F coax connector cables and put the antenna in a weatherproof box with Raspi+tuner so the cable length would be short. I used the Raspi’s WiFi for the internet connection so the box only needed the 12V power connection (used a 12V to 5V step-down converter).

2 Likes