8dBi 978MHz-1090MHz Antenna

FlightAware ADS-B Flight Tracking
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China too.

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Source: http://flyingandtechnology.blogspot.ca/2013/10/uat-or-1090es.html?m=1

UAT or 1090ES?

If you are considering ADS/B, there is a choice to make - a Universal Access Transceiver (UAT) or the Mode S transponder that has an extended squitter (1090-ES)?

It all depends on what country are you in? If you arenā€™t in the USA, then the choice is pretty much made. The USA offers the option of a UAT. The rest of the world needs Mode S transponders for ADS/B installations.

If you are in the USA, and you mostly fly above FL180, then the choice is pretty much made again. The FAA doesnā€™t allow aircraft flying above 18,000ft to use the UAT. It just makes sense to get the 1090-ES transponder that will do Mode S if you want take advantage of ADS/B and fly about FL180.

The UAT transmits and receives on 978MHz, the 1090-ES transmits and receives on 1090MHz. The ADS/B system will allow all participating aircraft to see each other. If the two devices work on different frequencies, how does a 1090MHz transceiver see a 978MHz transceiver? The ground stations will repeat the 978MHz messages on 1090MHz, as well as repeat the 1090MHz message on 978MHz. The ground station will also show both messages on the ā€œRADARā€ scope, so the air traffic controller knows where everyone is.

The 978MHz devices can handle more data (has more bandwidth), so more aircraft in a concentrated area will work without overloading ground stations or other aircraft.

The UATā€™s are even more useful, since the FAA will broadcast extra information. The two extra messages that the FAA is broadcasting are the TIS/B and FIS/B. The 1090-ES system will get TIS/B, but not FIS/B.

TIS/B is Traffic Information Service-Broadcast, where non-ADS/B equipped aircraft will show up on the aircraft display, similar to ADS/B equipped aircraft. The ground station will broadcast the position of aircraft that are only visible on RADAR. As a pilot, you will be able to see more of what the controller sees.

FIS/B is Flight Information Service-Broadcast. Flight information includes weather, and aeronautical products. While XM provides some weather, that you must subscribe to, the FIS/B is free to everyone. The XM product may have additional information, or be more timely. The FIS/B data is what the FAA will be looking at, including potentially air traffic control. The aeronautical products appear to be weather like items, such as NOTAMs and SUA status.

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Sweden too, and may be Korea (See my post156790.html?hilit=UAT#p156790 post).

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Hm, ok, I thought Sweden was trying to do it on VDL. Maybe that didnā€™t go anywhere.

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Of course an 978mhz with a high gain will be perfect fit, up the line with RG-6 cabling.

Also, keep in mind folk, the 978 , UAT, will give you the weather info ! Thatā€™s mostly the best or only real benefits of the adsb adoption let say. Flarm could had been used, but getting traffic is ok, in the air. Over 978 itā€™s little lower reception, so an already
tuned antenna for both is a very great idea for product. Hope itā€™s gonna be on Amazon.CA as well.

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I agree. I have Dump1090 working great and I have everything I need for a good PiAware978/Dump978 on a different system.

A good 978 antenna is worthless without a system to use it. Any word on one?

Thanks,
Steve

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I run dump978 with a 2nd dongle (using stock antenna) on the same Pi2 as dump1090. I feed the results back into dump1090, which sends to FA / FR24. The reason I can get away with the stock antenna is that I have direct line of sight to a local ADS-B tower/groundstation.

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Since you use stock antenna, see this post: How to improve performance of whip antenna of DVB-T
for 978 MHz (wavelength = 307 mm, 1/4 wavelength =77 mm), cut the whip 77 mm - 3 mm = 74 mm. The 67 mm shown in drawing is for 1090 MHz (wavelength 275 mm)

.

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Yeah, Iā€™ve been meaning to do that. Is the size of the ground-plane important? (i.e. does it need to be at least 67mm radius, or just the bigger the better?)

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(1) For 978 MHz (wavelength = 307 mm, 1/4 wavelength =77 mm), cut the whip 77 mm - 3 mm = 74 mm. The 67 mm shown in drawing is for 1090 MHz (wavelength 275 mm).

(2) Optimum height of Can is also 1/4 wavelength (74 mm fo 978 mm & 67 mm for 1090 MHz). However, the height of can is not so critical, and more or less height wont make much difference. You can try different cans to see which one gives best results.

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(1) For 978 MHz (wavelength = 307 mm, 1/4 wavelength =77 mm), cut the whip 77 mm - 3 mm = 74 mm. The 67 mm shown in drawing is for 1090 MHz (wavelength 275 mm).

(2) Optimum height of Can is also 1/4 wavelength (74 mm fo 978 mm & 67 mm for 1090 MHz). However, the height of can is not so critical, and more or less height wont make much difference. You can try different cans to see which one gives best results.

Height of can, or the radius/diameter of the top?

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(1) Diameter of Can:
I have tried cans of various diameters upto 100 mm.
Cans less than 2ā… inch (67mm) diameter gave poor results.
Cans with diameter 2ā… inch (67mm) and up to 3ā…ž inch (100 mm) gave nearly same result.
I did not try bigger than 3ā…ž inch (100 mm) diameter can. You may try bigger dia cans to find out if ā€œbigger is betterā€ holds true.

(2) Height of Can:
Optimum height is Ā¼ wavelength, but this has lot of tolerance and somewhat higher or shorter cans donā€™t make much difference. You can try cans of various heights to find which one gives you best result.

(3) Height of Whip:
This is most effective in improving performance. The optimum length of whip is Ā¼ wavelength (69 mm for 1090 Mhz & 77 mm for 978 MHz). Due to ā€œend effectā€, the whip is made few mm shorter than Ā¼ wavelength, i.e. for 1090 MHz 69mm - 2mm = 67mm, and for 978 Mhz 77mm - 3mm = 74mm.

  • Wavelength Ī» in mm = 300,000 / frequency in MHz*
    .
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Back to the 8db antenna ā€¦ if buying an antenna, higher gain is always preferable since this is likely to be a one-time purchase ā€¦ you can still add an amplifier later.

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I fully agree with Peter.
.

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So, is this new antenna definitely a go, or is it still being considered? What would the timeline be?

Thanks.

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[quote=ā€œdavid.bakerā€]We are thinking of adding in a batch of 8dBi UAT + ADSB antennas in our next shipment.
[/quote]

Any update on this? I am waiting on buying the DPD Productions UAT antenna, if this new FA antenna is coming to market.

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I want one, too!

Happy Halloween!

http://blogs.extension.org/childfamily/files/2014/10/Halloween1.jpg

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LOL :smiley:

Meeeee toooooo!!!

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[quote=ā€œsjacket99ā€]

As do Iā€¦ I got money burning a hole in my pocket waiting!!! :slight_smile:

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FlightAware will be doing a small run of the 8dBi dual frequency 978 and 1090 antenna. Available most likely after Thanksgiving and available on Amazon.

Test antenna are showing amazing range. Test antenna with amplifier beats anything we have tested at FlightAware.