FlightAware Discussions

Yet Another Antenna Question

Hi all,

I setup my Prostick Plus a few months ago, using the included antenna, placed on the window sill of my home office. I’m on a 210 meter hill overlooking the Dee Estuary and have an open view to the horizon on an arc of about 120 degrees (NW - E ish).

In an effort to see more data, I’ve bought a “FlightAware 1090MHz ADS-B N-Type Antenna 26” - 5.5dBi" from PiHut and installed it in the loft. I’m seeing a big improvement in numbers of reports and range. But, I have a solid wall in the loft space, separating the garage from the house and I think its blocking signals from the South & West. So, the next step will be to mount a pole on the (outside) gable end of the house and put the antenna on that.

Is it as simple as just bolting a bracket to the wall, clamping a pole to the bracket and attaching the antenna to the pole? Knowing nothing about radio, I’ve confused myself by reading about “ground planes” and “earth straps”.

Also, is there an optimum length of pole, or is it just a case of “the higher the better”?

Cheers,

H.

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If mounted outside, you will need to ensure copious waterproofing of the cable joints, using suitable tape. If the joints are further enclosed in a plastic box, ensure a small drain hole at the very lowest point to ensure that if water does get in, it has an easy way to drain out.

External groundplanes and earthing are important for medium wave and shortwave aerials. They become less important for UHF signals as this is usually built in to the antenna design itself.

I am surprised to see antenna gains quoted as dBi (gain over isotropic) by the maker. This is a device to “inflate the numbers”. Figures quoted using dBd (gain over a dipole) give a more realistic (lower) and more understandable number. Subtract 2.15 from the dBi figure to get the dBd figure.

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If it improves the distance of the objects on the horizon, higher is better.

So if you go 2 m higher and can then overlook a tree or house, that’s worth it.
The further away the obstacles, the lesser the impact of additional height in looking over them.
It’s line of sight, just that you can look through clouds :wink:

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Pretty well, it’s just a matter of mounting a pole any way you can and getting the antenna as high as practical.
Type-N connectors “should” be waterproof, but it’s worthwhile adding some self amalgamating tape to be sure.

The FA antenna is a ‘ground independent’ design, so you don’t need to worry about ground planes.
Something like the mag-base antennas rely on a “ground” to work. This “ground” may be a metal dinner plate or car roof. For now, that’s not your problem!

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Thanks all. Now for the hard part, “negotiating” with my beloved!

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