The 8dbi antenna is terminated (not open). Had to remove my power injected system to use it.
Reception is good with a 50 foot cable run but nothing special (without amplification). My home builds look to be superior but it will take a few days of data to confirm.
The āexceptionalā range you saw may have nothing to do with the antenna or rain, but it is probably a result of the UAT system design. The way how the UAT works is that FAA system receives the āUAT outā (also known as downlink UAT ADS-B message) transmission from participating aircraft, calculates what is inside 30NM by 3500ft āpuckā surrounding that airplane and then sends TIS-B (or UAT uplink) messages for each aircraft within the āpuckā. So, if you have a line-of-sight to an ADS-R antenna and an aircraft flying on the outskirt of your possible range (and you probably will not be receiving the downlink UAT messages from that aircraft) you will be receiving TIS-B messages intended for that aircraft which will manifest themselves as the āexceptionalā range on the polar plot. But I would not count on being able to reproduce that āexceptionalā range without the āUAT outā aircraft 250 miles from your location.
Edit: Sorry for mixing up TIS-B and FIS-B. Corrected now 
Itās TIS-B and downlink messages, but the basic principle there is correct.
(FIS-B is weather radar etc)
edit: you can identify this case if you look at the raw messages, TIS-B should (in theory) appear with a different address qualifier (āICAO address via TIS-Bā)
two days now and it looks good with positions reaching out to the 250+ range.
N to F connector with 70 ft of rg6 cable so the net gain at receiver is (~8-4=4db).
Iām guessing that installations with less than 40-50 ft of cable run would have peak performance.
This is a good antenna for those that donāt want to mess with amplifiers and power injectors.
[quote=āagretchā]
Iām fully aware of what Iām tracking. I view the traffic locally on VRS and use that as my range gaugeā¦ the FA range plot is useless when youāre picking up TIS-B. With the amplified FA dual band antenna, I wasnāt able to pick up the ground station a few miles from my house. Iām not too surprised because of the terrain, houses, and trees in between. The amplified cantenna picks it up just fine. With the FA antenna, I was lucky to pick up a ping or two from the practice areas 20nm to the NE and SE. Cantenna has no issues with those areas and gets the low altitude traffic 60nm to the north where I have an unobstructed view.
I can verify these claims because I put the cantenna back up this Saturday after a bit of weatherproofing and am reliably getting these numbers now. In short, after a couple weeks of comparing the cantenna vs. the FA dual band inside the house and a couple trips to the roof, Iām not impressed.
If I had HOA rules which kept the cantennas off my roof, sure the FA antenna would make sense, but my two cantennas are IMNSHO quite impressive. My 1090 ācanā has been on the roof for over a year and is still the top receiver in the Seattle, Vancouver BC, Portland area. Not too bad for the cost of a satellite amp and voltage blocker.
Did a full SWR scan of the new 8 db antenna and expanded scans at 978 an 1090.
I just replaced my FA 1090 antenna with the 978-1090 version. The main reason I swapped out the antenna was for the gain increase from 5 to 8db. However, the results are extremely disappointing. Previous to the antenna replacement I was consistently tracking 60-70 aircraft with peak distances of around 250 miles. After the replacement I am only tracking 2-6 with peak distances of 20-30 miles. Is it possible that I have a defective antenna or is there something else going on? Maybe there are some other adjustments I need to make to my setup?
My setup uses a 50ft cable run to the mast mounted antenna. I am also using the LNA4ALL preamp which is powered from a dongle with a bias-t circuit modification. This setup produces great results with the FA 1090 antenna. When I swapped out the antenna for the 978-1090 version, I get the poor performance mentioned above.
Does anybody have any insight or words of wisdom on what I am experiencing?
Rick,
I had issues just swapping the cables. I swapped a 3ft cable for a 6 inch cable and things got worse.
I swapped them back and it was still bad. I tried a third time and things got a whole lot better.
Ensure that the N male connector is a 50 Ohm version(even if using 75 ohm cable). It has a thinker pin. Hard to notice unless you are really paying attention. The smaller pin may not contact the socket properly.
The best way to solve most issues is to only change one thing at a time. If you have done this then look at the N to antenna connection. Was it screwed in far enough? Put back the old antenna. If it is good then you likely have a problem antenna. If not then maybe the cable or plug was damaged.
Jon
Thanks for the reply Jon.
My next step was going to be to put back the previous antenna to see if my performance would return to previous levels. At the time I make the swap, I will carefully check the N connector as you suggest to make sure there are no problems. If the the old antenna works as before, then Iām going have to assume that I have a defective antenna.
Unfortunately it has started to rain, so Iām going to have to probably wait until tomorrow to swap back the old antenna.
Do you have a DC block before the antenna?
No, I do not have a DC block. I contacted Adam (LNA4ALL) prior to setting up my installation and he assured me that a DC block was not needed:
āNo DC block required on the antenna side. The antenna is RF coupled through the 100pF capacitor.ā
Only differences I can think of is the āun-terminatedā standard 5 dB Flightaware vs the 'terminated" 8 dB antenna and the double amplification you should be getting with the new antenna.
Perhaps you are overloading the SDR with too much amplification .
Maybe test it without the amplification in the line?
I would remove the amp.
I would like to order one with delivery to Poland. Is there any chance to have it shipped to Poland? I believe Amazon is not allowing this option. Can you advise?
Thx
I would try stepping down the GAIN on your dongle. Do you have the collectd graphing enabled? That would make it much easier to see what is going on with your setup.
Cheers!
LitterBug
I would try stepping down the GAIN on your dongle. Do you have the collectd graphing enabled? That would make it much easier to see what is going on with your setup.
Unfortunately I do not have collectd enabled in my setup. However, I have lowered the dongle gain and even taken the amp out of the system and the results are no better and even a little worse.
Because of the rain we have had over the last couple of days, I have yet to get back on the roof to swap the original FA antenna back. At this point I suspect I either have a defective antenna or I somehow messed up the N connector when I put up the new antenna.
You might need to edit fadump file and change āgainā parameter. In my case I had to change from default -10 to 44. I just replaced my CoCo antenna to new one (homemade) and this new CoCo started rocking when I modified gain parameter.
The best way to solve most issues is to only change one thing at a time. If you have done this then look at the N to antenna connection. Was it screwed in far enough? Put back the old antenna. If it is good then you likely have a problem antenna. If not then maybe the cable or plug was damaged.
I am happy to report that the antenna is not defective and is now working great. It turns out that the problem was that the N connector cable crimp had lost its hold allowed the cable to slide down just enough to prevent the center pin from engaging female connection on the antenna. Once that was corrected, my plane count was restored to previous levels and then some. I must say I expected better from a cable with the connector āprofessionallyā installed by the cable supplier.
In any case, the additional 3db gain over the original FA 1090 antenna has made a noticeable difference. I donāt have collectd in my setup, so I cannot provide any quantifiable results, but the increase in planes tracked looks to be in the neighborhood of 15 to 20 percent and I quite pleased with the results thus far.
Hi Rick,
Your stats look great again.
You should have the best position report daily totals today for the last month.
Total A/C could be close with another hour to go, but you didnāt fix the antenna until after 23:59UTC so will need to wait until tomorrow night to get a full day of stats.
At the moment you are on track to have the best receiver in the area. Check it out in a week.
Jon
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Your stats look great again.
You should have the best position report daily totals today for the last month.
Total A/C could be close with another hour to go, but you didnāt fix the antenna until after 23:59UTC so will need to wait until tomorrow night to get a full day of stats.
At the moment you are on track to have the best receiver in the area. Check it out in a week.
Yes, I am quite pleased with the way things look now. My plane and position counts are way up. Thursdays and Fridays are typically busy days in my area (80 miles NE of San Francisco). Before the antenna upgrade I would see right around 1600 aircraft per day on any given Thursday. Today, my first Thursday with the new antenna, I will see just over 1900 aircraft, nearly a 20% increase. Thatās pretty good considering I have done no real tweaking or optimization of my dump1090 settings.