Hey All,
New here to the aspect of something more that the “plug n play” mentality of ADS. I am looking to build a robust 1090 system. I have ordered the DPD 1090 antenna, and LMR 600 (yes, I know its overkill, but I have alot leftover from previous helium builds). I am looking into what the more premium dongle would be. I am really liking AirSpy. I will be running off of a PI4 8G, wired 2.5gb LAN.
Need help with maximum coverage and clear messages. What dongles would everyone recommend? Also like the Nooelec SAWbird+ ADS-B, for amp and filter. Please excuse my “noob-ness”. This will go in Monroe County, Pennsylvania, will be at approx 960’ from sea level 30’ off the ground.
TIA
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Have you looked at heywhatsthat.com? It’s a really good place to start because you can enter your exact location and elevation and it will create range rings at your maximum distance for selected altitudes. It takes geography into account, but not foliage or any man-made obstacles.
It won’t help with your hardware choices, but it can help set reasonable distance goals. Here’s an example of the rings from my station - orange is 10,000 feet and blue is 30,000.
It also helps to keep in mind that you can only “see” planes where they are. You might have a theoretical range of 250 miles in one direction, but you won’t ever hit that range if there aren’t planes there. I never see planes more than 50 miles off of the coast from my station, even though I should be good to almost 150 miles at altitude. There’s just nothing flying out there.
There are some tutorials on this site for creating the range rings - the website isn’t super intuitive. Or say something here and someone will guide you through it.
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Your system is better than mine! Also about 32’ AGL.
The gospel to me is, and always has been, the higher your antenna the better.
Not an electrical engineering person, but I would wager even a tuned random wire outside beats the attic. My problems are trees and a hard-to-get-to mast.
I really need to fix that.
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Greatly appreciate the advice. I have looked at that a bit, but you reminded me to go back and reanalyze. Ultimately looking at these rings I should be able to pick up: Newark Liberty (EWR), John F Kennedy (JFK), LaGuardia (LGA), Philadelphia (PHI), Baltimore BWI, Dulles (IAD) and maaaaaybe Boston (BOS). Want to make sure I capture as much as possible the right way. Which is why I am trying to build something a bit differently. Old system is on an pro stick plus and a 5.5 adsb antenna on LMR400
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This is obviously true, but depending on the obstructions you are trying to overcome, the reality is that it can become impossible to raise enough to make a measurable difference.
Using my station as an example again, my antenna is 3 feet above the roof peak of my 2-story home. It is also 3 feet above any of my neighbors’ homes. If I raised the antenna 10 feet, I would stil be below a few nearby trees (would have to go up probably 40 feet to clear them), and in most directions my other obstructions are at least 10s of miles away. I have some 4,000 foot mountains 40 miles to my east. With my “fulcrum” 40 miles away, raising my antenna by any reasonable amount won’t make a significant difference on the other end. I’m not sure if I am explaining that well, but it makes sense to me!
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It would be interesting to know what jbelvin’s view of the horizon is in a 360 degree span around the proposed 30 foot antenna. His position of 960’ above sea level may put him at an advantage, but possibly in only a few specific directions. Are you blessed with a hilltop location?
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The yellow ring is for aircraft at 10k ft, the blue ring for aircraft at 30k ft.
At least if you leave it at the default setting.
Thus listing airports is kinda misleading as that at least to me implies low level coverage 
Really i doubt you’re gonna see significant range improvement, maybe a bit.
Once you have a decent system which the above is, you only get minor improvements.
Switching to an airspy can bump up the position / message rate and makes it easier to receiver low flying close by and far away planes (dynamic range).
If the range is limited by terrain (your previous setup likely was), there really is no way to get around that.
So an airspy might to be able to get a bit more range but you can’t expect miracles.
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That’s basically what I was talking about - looks like you would need to go up another 30-40 feet (or more) to clear those trees on the left, and they are so close you would need to nearly match their height to gain any distance in that direction. With the trees to the right you might see some improvement with only maybe 10 feet. It’s all about reducing the angle from the antenna to the top of the obstruction(s).
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Yes, tnx, see my earlier post.
…fear of heights & lack of materials.
Chain link fence top rail pipe makes pretty good mast pipe for a light antenna like we use in this application. With all those trees for a wind break, I doubt you need wire tie offs for support there. Less detail to have to manage.
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Another 100 feet would be better. 
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Those aren’t guy wires. They’re two legs of an old 20m hf inverted “V” 1/4-wave dipole.
The wind has since taken care of those 
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Ah the inverted V. I have one of those positioned on my radio tower that I can raise and lower as the weather changes. Yes, they did look a bit slack for actually being guy wires. Does the wind blow in Schenectady?
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To be honest, It does not exactly blow in Schenectady, New York City Sucks. Just personal opinion, and yes, I have been there. Don’t get me started on Long Island…
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Once in a while it does. My rigging performance ain’t what it used to be.
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