DIY Antenna


#1

Hi,

I am new to this ads-b tracking, and recently got a receiver set up. While waiting for the hardware to get in, I read a bit about making your own antenna to extend the range of the receiver over the standard antenna that ships with the receiver (and which is supposed to be crap).

After a couple tries (one dipole, one colinear coaxial, and another I can’t name), all the antennas, while getting some signal are significantly worse that the original antenna. I am no electric/electronic engineer, so I am probably missing some essential point to antenna design that is so obvious that all the DIY site omit to tell about.

Any help or input on topic would be appreciated.

Regards


#2

The supplied antenna works reasonably - it’s main problems are that the wire that comes with it is very short and the base isn’t waterproof.

The co-axial co-linear is difficult to get right.

The dipole is simple - just trim the arms to 68mm each

If neither worked for you, then you might have a problem with your antenna connection or with the MCX adaptor to the USB dongle


#3

Hi,

Thank you for the feed back. I will work on these a bit more, and see, if I can get better connections. Actually I was wondering, how accurate must the length be? when you say that each rod of the dipole must be 68mm, this gives a total length of 136mm, while the DIY cork antenna state a 137mm length including the gap between both sides. Does the 1 mm difference make a big deal, on the range?

In the same type of questions, how do I determine the speed attenuation factor of my coax for the coaxial colinear antenna? (short of using a scope, and a very long section of coax).

What kind of range improvement should I expect with a DIY antenna, over the stock antenna?

Regards,


#4

136/137 - I wouldn’t have thought it would make much difference - you can’t tell from a forum post just how much care people have put into what they’re doing.

Someone else here has written about the poor performance of their antenna … in their case the problem seems to be a 900mhz cell tower 200 meters away swamping the reciever.

all we can do is offer solutions.

A dipole should offer at least as good a signal as the supplied whip if in the same position - that would be a reasonable test to make sure assembly is ok.


#5

I built a 3ft collinear with rg6. Cut the sections to 6in and cut off little under an inch on each end. Insulated and put inside a ovc pipe. Its connected with a 25ft rg6 cable directly to my receiver. I have tripled the amount of planes I saw with the small whip antenna