yagi - do you have experience with directional antennas?

Thanks for the replies guys. Yes I know I would have to ask Flightaware for approval, before changing antenna (or adding diversity antennas). But my post here was just to hear what other have experienced, using yagis.

For now I will just move the antenna slightly, so its above of my other antenna on the chimney.
Later I will get rid of the 15m long feedline, and place the receiver close to the antenna.
I cannot use preamp here, as I transmit 1kW on HF & 50MHz nearby.

JoePPi makes a good point regarding Tropo ducting. Yes the duct will be below most planes, so even when you receive planes far away, it does not mean you have good coverage at high altitude.
I remember receiving a plane and a helicopter at about 1000ft near Shetland, during my first days of operation. But it was no reception in that area at high altitudes.

I will have a look at the gain setting. Actually I live in a very quiet location, so it might be something to gain there :slight_smile:

Regarding GPS, a 1090MHz yagi, would work as a badly tuned dipole on the GPS frequency. It probably would work just fine with clear view to the sky.

Most preamps have a high pass filter fitted before the amplifier anyway, at least those aimed at ADS-B. Don’t know which hardware the flightfeeder is exactly, but i suspect they have at least some sort of LNA fitted.

There is a built in bandpassfilter in the unit, but filters are not infinite, so using 1kW close to the antenna will probably overload the receiver somewhat, even if its 1GHz lower. I looked at the settings on the F.A. receiver (v10) now, but it was no way to change gain settings using the screen.

Modesbeast receiver + RPi.

Major change is splitting up the total gain into two ERA-3 devices, so one of them is placed before the first filter, and so improving the total noise figure by about 3dB and the sensitivity by 3.5dB. Also the whole chain is matched, which results in a flatter passband.

The orange FlightFeeder doesn’t have any filter, it has the FA Pro receiver stick. You would gain something if you use in front of it a SAW filter (or even a cavity filter).
SAW are cheap and very efficient.

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I have created an “Alternative Dipole System Beam (ADSB)” for the fun. more info photos on https://www.qrz.com/db/PD0G

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@PD0G

Great build!

A couple of questions.

  1. It looks like you don’t have a phasing harness, is that correct?
  2. Can you post the lengths and spacing of the elements please?

I also used the plastic water pipe when I made a single Yagi. I posted some numbers and photos above. Sorry but the photos disappeared when the forum was updated. It didn’t work too well as I got a lot of signal from the back of the antenna.

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If you look on his site you’ll see that active element is just one lambda/4 wire in the middle pipe.
I am not sure how well that asymmetrical element couples in RF domain with the symmetrical directors.
The location is great, high and open horizon…

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I used a dipole and fed coax 70ohm

They are 4 yagi but… without the reflector… and 1 dipole.

I’m looking at adding a second antenna, this time a directional. The various Baz yagis that Jetvision and Excel sell are fairly expensive. However, there’s this cheaper option here. Has anybody used this particular antenna?

1,000 km range?
From the top of Everest tracking a U2 at 70,000+ feet, maybe…

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When properly installed without obstructions, the antenna can receive ADS-B data from aircrafts up to 1000 km away.

coughbullshitcough

That sort of claim is a serious breach of advertising standards.

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Well if you count the earth being round an obstruction … :wink:

Or for tracking a ghostly space shuttle I suppose?

The American company I now work for advertises the range of its product with zero fade margin.
Charlatans, the whole lot of them.

I don’t know what the European laws for false advertising are but if that was a UK seller, I’d be reporting them to the Advertising Standards Authority tomorrow. The trouble is that someone might believe it. It’s probably a perfectly good aerial but that sort of claim is utterly ridiculous.

The manufacturer is likely a ‘flat earth’ aficionado. The Flat Earth Society has members all around the globe, so don’t discount the possibility. :smiley:

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How can that be so if the Earth is flat?

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If you lived in the Canadian province of Saskatchewan, you would be forgiven to think the earth is flat, as residents can see their dogs running away for days. :wink:

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Dxista, this is too funny, well done!

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