FlightAware Discussions

How do I know if my PiAware is working optimally?


#1

I just started my PiAware Site 91665 – KSTS with a
. Raspberry Pi 3
. FlightAware Pro Stick Plus ADS-B USB Receiver Built-in Filter
. 1090Mhz Antenna MCX Plug Connector 2.5dbi gains ADS-B Aerial with Magnet Base RG174 1M+MCX Female to SMA male Adapter Connector
. Miuzei Raspberry Pi 3 B+ Case Fan, Heat Sinks, 2.5A Power Supply ON Off Switch, Open-Air Cooling Case

For the first day or two, I had the antenna lying flat on a shelf.
Should I cut the antenna to 87 mm? That seems like a “no turning back” thing to do.

I have a skylight in my office, so I stuck a piece of L-shaped steel to the wall of the skylight opening, up high, so the antenna is upright, but against one wall.

How do I tell if this is a decent orientation for the antenna?
My Stats page shows between two and five “Flights … from this feeder” during the day. Not much going on around here at night.
If I look at a flight log, there is usually only one entry with my name on it. I have plotted the GPS locations, and they seem diverse, mostly to the east of me, but a few to the west.

SkyView shows some planes in my area. Are those planes I can see, or planes in my area?

My Aircraft Reported looked better in the days when the antenna was lying flat, five feet off the floor.
Now that it is upright, 10 feet off the floor, the total flight count has dropped, but, I don’t know if that is representative.

image

– Clarence


#2

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(1) It should be cut to 67 mm, not 87 mm.

(2) No need to cut the antenna. Unscrew the whip from base, and use steel tie wire OR a thin wire from old/scrap network or telephone cable as whip :slight_smile: The vertical length 67 mm, plus some quantity to wind few turns on the screw on base.

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Steel%20tie%20wire

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Network%20cable


#3

These antennae are terrible and you have it inside where most of the signal is absorbed in the building walls and roof.

Compare each of the graphs and tables on your Stats page https://flightaware.com/adsb/stats/user/ClarenceDold with https://flightaware.com/adsb/stats/user/av8rdav who is located 6 miles from you.

His Flights with Positions From This Feeder is full (20 aircraft) whilst yours has only 4.

He might be perfectly sited on a hill top with his antenna having a clear view to the horizon but it is unlikely only 6 miles from you.

It is most likely he ahs an antenna that is significantly better than the cheap mag based antenna that come with the dongle.

It is also likely that his antenna is mounted higher and outside where the signals do not have to pass through walls.

There are numerous discussions here about using http://heywhatsthat.com/ to estimate how far you should see aircraft from your position at 30,000 or 40,000 feet.

There are also many discussions on the best antenna to use.

I get maximum range with a home made Coaxial Collinear Dipole antenna or a Flightaware prebuilt antenna. (Amazon).

The Coaxial Collinear is difficult to make but very cheap.

If you just want it to work I would recommend spending the $40 and getting the Flightaware antenna and mounting it in clear outside.

S.


#4

That antenna comes ready to go for 1090MHz, don’t cut it. I had one on a windowsill, it worked great, pulled in aircraft up to 100NM away no problems, sometimes a bit over that. I mounted it upright on a small tin and that improved its performance a lot. You can see how it looked in this post.


#5

if 8v8rdav is where it says it is, it’s in a nice flat plain. I am closer to the hills, and I have a row of redwood trees to the north.
Another that is nearby would be rseghieri. Also more open terrain, but stats that are close to mine.

Nice thought about using the nearbys as a guide.
I expected North Coast Aviation to be better, being “in the biz”. I guess the public exposed location is truncated, because that site would presumably at the airport, and the "location " is near the airport.

Too bad there’s no antenna and site info in the station information.

I made colinear antennas and some cantennas when WiFi first came out.
I might buy a FlightAware antenna. First, I might just try this one out through the skylight hatch.


#6

Yes, that is great.

Even better.

However the OP asked How do I know if my PiAware is working optimally?

If you compare your stats with This station 7 miles from you you will see that there is the possibility of very, very significant improvement potential for your receiver.

S


#7

:grinning: That would make life much too easy to compare.

That’s the idea! It is an excellent method for gauging how well you are doing. When the bug really bites you will do what many others do and have two complete identical receivers. One you keep as a reference and do all your mods on a second one. Run two versions on Skyview side by side and then judge in real time if your single modification improved things …or not.

That will make it better but it will be best for what it is if it is mounted on a metal groundplane of some sort and the radiator is vertical.

That will certainly save you a lot of grief.

There are many threads you should also read about minimizing losses in your coax and connectors and adaptors.

The Pro Stick Plus has both amplifier and band pass filter and should be very good until you can establish there is a problem.

S


#8

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Check what maximum range you can get

What is the Maximum Range I can Get?

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#9

The cable of that antenna alone is atrocious. I think i bought one of them too advertised for 1090 MHz but making it a true quarter wave stub still increased it’s performance.

For the beginning you can try a can or other metal surface below the antenna. (that’s what the magnetic mount is for)

Depending on what is in that ceiling the skylight stops reception very well in all directions.
The antenna should have line of sight to the airplanes just like when you try to spot them with your eyes. (Antenna can see further though ;))

If you have made antennas before why don’t you get some CFD200/LMR400 SMA terminated cable and cut off one end and make that end a quarter wave with radials.
(Spider with radials shoved into the outer conductor mesh)


#10

I’m going to say that is pretty representative.
I see a few planes out to the west over the ocean, but there isn’t that much traffic out that way.
I see about to the Golden Gate Bridge, some over the San Pablo Bay, the bulge in the water just above the San Francisco “dot”. I certainly cover all of the yellow outline, plus a little more. I was tracking a helicopter on Clear Lake, just outside the yellow due north.


#11

Looking at the Nearby list for SITE 91665 – KSTS ClarenceDold, to see how I compare, I see n112 listed three times, with “nearest airport” as three different airports, but the same location.
The flights seen are different, and none of the airports are “nearest”.
What’s going on there?


#12

The Nearest Airport can be entered manually and as far as I know have no affect on the data.

My Nearest Airport comes up automatically when I start a new receiver as the nearest to me hospital emergency helipad. Hardly an Airport. I had to look the location for YAFD. The next closest Airport is another hospital emergency helipad.

Different receivers at the same location invariable provide different results.

S


#13

I have that “center load” load antenna, 170mm.
I had an “individual” pie tin, with a 75mm base.
I cut the bottom out that, stuck the antenna to a piece of steel through the aluminum.
I don’t know that was any improvement at all.

It’s higher than before, a little farther out from the wall before, and has a ground plane.
Do i need the spider legs? Is the 75mm ground plane the wrong size?
I could use the full pie tin in either orientation, maybe slotting it for the mounting arm.


#14

There’s always a way to optimise one’s setup. I’m using a FlightAware antenna indoors. Mounting it outdoors high up would be a big improvement. In regards to the ADS-B whip antenna, to optimise it, don’t cut it, as that applies to generic DVB-T antennas and this is a pre-tuned ADS-B antenna, and mount it upright on a groundplane, not have it lying flat on a shelf. Those two things will help a lot.


#15

As I looked at this picture, I started thinking about minimum bend radius.
The excess cable is folded back on itself at the original shipping fold points, and not folded as tight as the original.
I opened those folds into a lazy bend, and I think my range is improved.
Looking at SkyView, I am consistently seeing some flights 80+ miles.
Looking at my statistics page, day by day, the change from no ground plane to a 75mm aluminum plate is obvious. I can’t see the effect of my unfolding, yet.
I notice that my 50-100 statistic is 10% of the <50. That was 3% with no ground plane.

Is 75mm enough of a ground plane? Is aluminum okay? As I was rummaging for the bracket, I spotted an old 10" steel saw blade :wink:

Sometimes I wish I had paid more attention to radio waves in USAF tech school, but I just maintained what was already there, and had no interest at all in tinkering or designing.

It would be handy if one could click on the flight of interest in the list at the right of SkyView, and have the info box pop up in the map on that flight, the way it does when you click on that aircraft.

It would also be handy if a particular track and aircraft listing would stay for a minute in different color indicating “lost”, so I could tell what the max range was in different directions.

I have one at 250+ miles.
The polar view is not strongest in the direction I would have expected.
The “clear view” in the skylight hatch is not the direction with the best distance.
It’s almost as if the wall/attic/roof have less impact than the two story house in the clear direction to the east, and the redwood trees to the north.

I’m loving this $30, so far.
Somebody gave me the Pi, and I couldn’t figure out what to do with it until piAware.


#16

Just a thought, but without magnetic attraction, will the aluminum really become part of the antenna [circuit]? I don’t know the answer, but I’m sure others here will. (I think your antenna is magnetic mount, right?)


#17

The magnet is just to hold it down, but is not part of the circuit.
It’s the close proximity that capacitivly couples the base with the ‘ground plane’. The magnet is just a convenient way to keep it ‘close’.


#18

I took out the ground plane and went for a six legged spider at 45 degrees.
I also reduced the aerial to 67mm.
My range typically shows 50-100 mile counts that are 18-20% of the <50 counts.
With the original antenna, with the ground plane, I was below 10%.


#19

Thanks for the explanation.


#20

The braid of coax is connected to the 1 inch (25mm) dia base plate. A small magnet of about 10mm dia is glued to the base plate. Please see photo below.

The base plate is the ground plane, and magnet keeps the antenna attached to a iron plate (like roof of a car or a food can), keeping it upright and firmly held in position.

The electrical connection between antenna’s base plate and the food can or car roof is not direct, as there is a black circular insulating tape over base plate. It is through the capacitance formed between base plate and food can which provides the electrical connection.