Ranking & How To Get It Better?

[chrischelt]

Hello again everyone,

I've been feeding in for 6 days now and I have liked watching my Ranking getting better but I'm wondering what more I can do to get it perfect?

I've purchased an aerial mount thing for my wall so I can stick the antenna up as high as possible but where it is now I am getting 155nm which seems good so when it's higher I am expecting good things.

[abcd567]

As a first step, determine what maximum you can get (the maximum range depends on the terrain around antenna location).

Once you have this benchmark, compare what range you are currently getting. This comparision will give you an idea how much improvement you can make.

Improvements can be made by :

- Moving antenna from indoor to outdoor
- increasing antenna height
- Reducing length of coax
- Adding an RF Amplifier (LNA)
- Adding a filter

What is the Maximum Range I can Get?

[chrischelt]

I've spent this morning out in the rain putting up this new bracket and now the antenna is above my roof and everyone else's but my distance doesn't seem to have changed which is rather disappointing...

I'm not sure why it hasn't gone up a bit at least considering the huge difference in hight.

[Runway 31]

Usually takes around 7 days for the max range to show a difference, give it some time.  If you want I can rest the polar diagram to let it grow again

Its not just buildings that affect coverage but your surrounding topography, trees, hills etc

What type of antenna and cable are you using. What length is your cable run.

Alan

[chrischelt]

Hi Runway 31,

I purchased the bundle Radarbox24 does with the antenna and stick. I have noticed from day 1 that the range has gone up a bit each time I have moved the antenna about to different places so I had expected a nice boost since moving it higher. I do have hills to the north-west area but I am getting down to just inside London and virtually all of Wales. Southwesterly I am getting down to Exeter so I am getting a good wide area but I was expecting to get full southwest, London and almost Scotland.

[Runway 31]

Up to 175 miles now and filling out a bit so getting better, give it some more time

Alan

[chrischelt]

I've just noticed it's up to 175nm now :-) progress

[abcd567]

Antenna height is an important factor in performance, but it is not the only factor. There are some more factors to be considered.

(1) The coaxial cable between antenna & receiver introducess attenuation (loss) of signal strength. This loss depends on (a) quality of cable (b) length of cable. If length is long or quality is poor, the attenuation may be high enough to offset the improvement by increasing antenna height. This can be overcome by using better quality coax and shorter lengths. In many case it is not possible to reduce the length of cable. In such cases using a LNA (amplifier) is a handy solution.

(2) Interference by strong cell/mobile phone and other signals can overload the receiver and considerably drop the performance. If you have cell/mobile towers nearby, you may face degradation of performance. The solution is to install a filter between antenna & receiver to reject unwanted cell/mobile signals, and pass only 1090 mhz signals to the receiver.

Do I Need a Filter?

[Runway 31]

Up to 186 miles now with less coverage to south ease and east than in other directions

Alan

[wiedehopf]

You really want the green AirNav stick, it has a builtin amplifier and filter.

Tips on how to modify the small indoor whip antennas has probably already been posted.

Or if you want to go for something more elaborate, you can use an external LNA: https://github.com/wiedehopf/adsb-wiki/wiki/Useful-items-for-purchase#highly-recommended-combination-of-lna--dongle

An external LNA even allows installing the LNA close to the antenna and then running coax to the receiver.
That arrangement allows using cheaper coax for most of the cable run.

[abcd567]

I purchased the bundle Radarbox24 does with the antenna and stick.

3 Easy DIY Antennas for Beginners

[chrischelt]

Over the past few days it has shot up and the map looks great. I am now showing 319nm and my UK ranking has got to 98 so far :)

I am thinking of getting an even longer pole to get it just that tiny bit higher still. I've managed to track several Airbus Beluga which I had no idea were in the area so often. I tracked the one and it was so close I went into my garden and could just about see it off in the distance which was nice.

[chrischelt]

354nm now and down to rank 50 for the UK so far and 429 World Wide :)

[chrischelt]

It's absolutely tipping it down here but I have just installed my aerial even higher on a bigger pole to try to get the little bit extra range :-)

Hopefully, it will take me up to at least 400nm

[chrischelt]

I seem to have almost full UK coverage now which is great. It's not 100% yet but only did the change yesterday so things might need to settle down :-)