My Attempt at a $115 ADS-B Receiver Build for Foreflight

Had the same issue. But I pulled the connector out with a pair of pliers. Hopefully, I didn't cause any disconnection.

Scrabo said:
Is it just me but how the hell is the metal antenna meant to screw on to this !!!
Click to expand...
 
Anyone else having intermittent traffic, even when at least 1 tower is reachable? Version 3 of the code, original build of hardware
 
ja_user said:
Anyone else having intermittent traffic, even when at least 1 tower is reachable? Version 3 of the code, original build of hardware
Click to expand...


Unless you're in an ADS-B out equipped aircraft, traffic will be intermittent.


Sent from my iPhone using Tapatalk
 
ksp_530 said:
Had the same issue. But I pulled the connector out with a pair of pliers. Hopefully, I didn't cause any disconnection.
Click to expand...


Just got the replacement this morning and it was better. They certainly don't give you too many threads to play with !!
 
RotorDude said:
There is a new thread on reddit discussing power supply issues. It's clear that USB power cables are the main potential culprit. Even a perfect USB supply that can deliver mega-amps at 5V would not help if your cable/connector impedance is too high, as it would be for the cheaper brands. The solution is to use high quality USB power cables and connectors, as short as possible (every inch counts!).
Click to expand...


Going to try a new power cable....
 
When I see things like ..." modified v0.1r3 image with dump1090 enabled and max_usb_current=1 )" - are these folks just changing a file on the SD card or is this a source code change and recompile ? Is dump1090 on the standard R3 image ?

This stuff is all new to me.
 
Scrabo said:
When I see things like ..." modified v0.1r3 image with dump1090 enabled and max_usb_current=1 )" - are these folks just changing a file on the SD card or is this a source code change and recompile ? Is dump1090 on the standard R3 image ?

This stuff is all new to me.
Click to expand...

I think there is a way to edit just a text file, but it might be easier to try the new image (still experimental), which has this plus other fixes.
 
Scrabo said:
Just got the replacement this morning and it was better. They certainly don't give you too many threads to play with !!
Click to expand...

lucky_zps8972c858.jpg


Tomorrow for me. Got the GPS / AHRS chip on the way from Taiwan as well in anticipation of better things!
 
My GPS/AHRS chip arrived today.
(and will sit untouched for at least a couple weeks)
 
dans2992 said:
Unless you're in an ADS-B out equipped aircraft, traffic will be intermittent.


Sent from my iPhone using Tapatalk
Click to expand...

Of course, but not off one minute and one the next for large areas. Today all traffic was at my altitude, it didn't matter if I was on the ground or flying, all traffic was always at my level.... Moving the antenna a little did help considerably with the coverage.

Radar coverage also came and went, but less so than traffic.
 
Hate all the "UUU" & "eee" displayed in WingX

I know it means 'u' is for TIS-B + UAT traffic. 'e' is for 1090ES traffic. It'll fill in a 'u' or an 'e' for each packet it receives, up to 8 characters. If the tail number is available, it will place it in the front up of the tail up to 8 characters. So you'll see flights like eDAL1234, eeeUA221.

Apparently you can remove them see https://github.com/cyoung/stratux/issues/18 but it sounds like editing files and recompile the source.... dont know if I want to go there just yet !!
 

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OK, gang. I admit to being totally ignorant of the ins and outs of ADSB receivers. I ain't too bad at audio/RF/uWave circuit design but competence in one field does not guarantee competence in something you've never dicked with (excuse me, heuristically experimented) with.

So, having read this thread from cover to cover, I'm still totally ignorant of the current state of the art and understanding what you all are achieving. Is there a "Compleat Dummies Guide To This THread" posted somewhere?

Make you a deal. If somebody can gently lead me into the understanding of this subject, I'll give you detailed plans for the best damned antenna in the world to make this sucker jump tall buildings in a single bound.

As we say, some people learn by reading. Some learn by watching. Some just have to pee on the electric fence for themselves.

Thanks,

Jim
 
Mike5250 said:
What antenna is that?
Click to expand...

Would like to know as well.... was thinking of using the antennas from a non-working Skyradar unit, with the SMA/MCX from Amazon.

By non-working - mean it was driven over !!!
 
weirdjim said:
OK, gang. I admit to being totally ignorant of the ins and outs of ADSB receivers. I ain't too bad at audio/RF/uWave circuit design but competence in one field does not guarantee competence in something you've never dicked with (excuse me, heuristically experimented) with.

So, having read this thread from cover to cover, I'm still totally ignorant of the current state of the art and understanding what you all are achieving. Is there a "Compleat Dummies Guide To This THread" posted somewhere?

Make you a deal. If somebody can gently lead me into the understanding of this subject, I'll give you detailed plans for the best damned antenna in the world to make this sucker jump tall buildings in a single bound.

As we say, some people learn by reading. Some learn by watching. Some just have to pee on the electric fence for themselves.

Thanks,

Jim
Click to expand...

Short story:

Take a Raspberri Pi (small board that can run Linux and has SD storage), add a USB software radio receiver to it, and a wifi usb dongle.

The end result is you have a computer that is capable of receiving ADS-B data and is also capable of making a wireless network to shove the data into the aviation applications. Of course this takes software to accomplish, which is open source and under active development.

This means, for like a hundred bucks, you can now get free NEXRAD radar data, weather data, and limited traffic data into Foreflight in flight.

Folks are experimenting with adding a GPS receiver and "solid state gyro" so that the AHRS type features in apps such as Foreflight will work.

I'm working on getting a case design out the door that will encase all the hardware nicely. The real need for the project at this point is figuring out how the hell to build a nice antenna inside such a case like the Stratus already has.

Raspberri Pi:
http://www.amazon.com/gp/product/B00P2UOU72?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Software radio receiver:
http://www.amazon.com/gp/product/B00P2UOU72?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Software:
https://github.com/cyoung/stratux

Lots of discussion about it:
https://www.reddit.com/r/stratux
 
jesse said:
Short story:

I'm working on getting a case design out the door that will encase all the hardware nicely. The real need for the project at this point is figuring out how the hell to build a nice antenna inside such a case like the Stratus already has.
Click to expand...

Hey, nice upgrade thought. I'd be happy to beta test that as well!! :yes:
 
jesse said:
Short story:

Take a Raspberri Pi (small board that can run Linux and has SD storage), add a USB software radio receiver to it, and a wifi usb dongle.

The end result is you have a computer that is capable of receiving ADS-B data and is also capable of making a wireless network to shove the data into the aviation applications. Of course this takes software to accomplish, which is open source and under active development.

This means, for like a hundred bucks, you can now get free NEXRAD radar data, weather data, and limited traffic data into Foreflight in flight.

Folks are experimenting with adding a GPS receiver and "solid state gyro" so that the AHRS type features in apps such as Foreflight will work.

I'm working on getting a case design out the door that will encase all the hardware nicely. The real need for the project at this point is figuring out how the hell to build a nice antenna inside such a case like the Stratus already has.

Raspberri Pi:
http://www.amazon.com/gp/product/B00P2UOU72?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Software radio receiver:
http://www.amazon.com/gp/product/B00P2UOU72?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Software:
https://github.com/cyoung/stratux

Lots of discussion about it:
https://www.reddit.com/r/stratux
Click to expand...

Wrong link for the Pi: here is the kit from Amazon:
http://www.amazon.com/Adapter-20-Guide-Clear-Case-Power-Supply-Kingston-Adapter-HDMI/dp/B00MV6TAJI
 
jesse said:
Short story:

Folks are experimenting with adding a GPS receiver and "solid state gyro" so that the AHRS type features in apps such as Foreflight will work.

I'm working on getting a case design out the door that will encase all the hardware nicely. The real need for the project at this point is figuring out how the hell to build a nice antenna inside such a case like the Stratus already has.
Click to expand...

Perfect, exactly what I was looking for. The Cliff's Notes version.

Antennas R Us. Describe the case. Is the signal polarized vertical, horizontal, or circular (RH or LH)?

Is this box meant for permanent installation in the aircraft or portable? If permanent, why not just use a transponder ("bb nose") external antenna?

Jim
 
Last edited:
RotorDude said:
Antenna:
http://www.rfsupplier.com/antenna-978mhz3dbi-plug-straight-radio-p-2658.html

90 degree adapter:
http://www.amazon.com/gp/product/B00V0Y4WDQ?ref_=cm_sw_r_awd_aeY5vbK2K1T8C

(Per this thread on /r/stratux)
Click to expand...


You do realize that if they are only getting 30 MHz bandwidth at a gig, all that is inside that black radome is a piece of # 14 wire stripped from a hunk of Romex? And soldered to a regular old SMA/OSM connector available for a couple of bucks? Same for the right angle adapter.

Jim
 
Scrabo said:
Is there one for 1090 ?
Click to expand...

According to 'lastdeadmouse' here, he is using a single 978 antenna in his devbox with a duplexer for the 1090, which he says is easier to pick up (and presumably less critical antenna-wise).
 
weirdjim said:
You do realize that if they are only getting 30 MHz bandwidth at a gig, all that is inside that black radome is a piece of # 14 wire stripped from a hunk of Romex? And soldered to a regular old SMA/OSM connector available for a couple of bucks? Same for the right angle adapter.

Jim
Click to expand...

Yes, there are rtl-sdr adsb DIY sites that consider it a sacrilege to buy an off the shelf antenna and have lots of DIY instructions for the solder-happy crowd. Kind of like putting the egg into a Betty Crocker cake mix. :)
 
RotorDude said:
Yes, there are rtl-sdr adsb DIY sites :)
Click to expand...

Do me a favor. Until I get spun up on this stuff, rtl-sdr is unreadable. rtl to me is "resistor-transistor logic", the first family of digital logic that Fairchild came out with in the mid-60s. sdr is a shottky diode rectifier. Somehow I don't think that is what you meant.

DIY is pretty prevalent. At least in the crowd I hang out with.

However, nobody has answered me yet the polarization of what you are trying to hear.

Jim
 
I ordered my parts at 11pm on Monday night on Amazon with 2 day free shipping. Parts should be here tonight, and will be flying by Friday. Hope it works! :)
 
weirdjim said:
Do me a favor. Until I get spun up on this stuff, rtl-sdr is unreadable. rtl to me is "resistor-transistor logic", the first family of digital logic that Fairchild came out with in the mid-60s. sdr is a shottky diode rectifier. Somehow I don't think that is what you meant.

DIY is pretty prevalent. At least in the crowd I hang out with.

However, nobody has answered me yet the polarization of what you are trying to hear.

Jim
Click to expand...

RTL = Realtek
SDR = Software Defined Radio
Here is one of the sites: http://www.rtl-sdr.com/

The combination of the RTL device and SDR technology makes this low cost DIY ADSB possible.

The cool thing about SDR is that using this technology and a fast processor you can emulate many radio designs using pure software.
 
weirdjim said:
Do me a favor. Until I get spun up on this stuff, rtl-sdr is unreadable. rtl to me is "resistor-transistor logic", the first family of digital logic that Fairchild came out with in the mid-60s. sdr is a shottky diode rectifier. Somehow I don't think that is what you meant.

DIY is pretty prevalent. At least in the crowd I hang out with.

However, nobody has answered me yet the polarization of what you are trying to hear.

Jim
Click to expand...

Jim,

Take a look at these links:
http://www.sprut.de/electronic/pic/projekte/adsb/adsb_en.html
http://www.rtl-sdr.com/adsb-aircraft-radar-with-rtl-sdr/

Antenna

The transponder signals are vertical polarized. A vertical polarized antenna tuned to 1090 MHz is required to receive this signals. The simplest solution is a vertical wire or metal stick of 13 cm length , this is the half wavelength of the 1090 MHz signal. Such an antenna is an electric dipole and receives signals from all directions.

To improve the antennas sensitivity multiple electric dipoles can be combined. But if they are placed side by side, then the antenna would not be an omnidirectional antenna anymore. Consequently the individual dipoles have to be placed about each other. Finally the dipoles have to be interconnected, but upper and lower end of each dipole oscillate with 180 degree phase shift. To connect them 130mm long horizontal loops have to be used. They work as 180 degree phase shifter.

Dipoles and loops should be bended from one long piece of wire. Its diameter should be large enough for the necessary stability.. The lowest point of this dipole-group has to be connected to the middle wire of an 50-ohms coaxial cable.

Now we need a "dummy-ground", that has to be connected to the shield of the coaxial cable. A round piece of sheet metal (13 cm radius) would be great, but some radial wires can be used instead. At least 4 wires (90 degree interspaced) should be used (groundplane-antenna). "Dummy-ground" and dipole don't have to touch each other!

This is just a basic design. The impedance of the antenna is not matching the impedance of the cable (but can be modified by bending the "dummy-ground"-wires downwards. Longer or shorter connection loops between the dipoles can change the elevation angle of the antenna ....... Antenna design requires knowledge, experience and luck.
Click to expand...
 
Scrabo said:
Would like to know as well.... was thinking of using the antennas from a non-working Skyradar unit, with the SMA/MCX from Amazon.

By non-working - mean it was driven over !!!
Click to expand...

SMA is easy, no adapter needed: http://www.amazon.com/RTL-SDR-Blog-...UTF8&qid=1441225741&sr=8-2&keywords=sma+820T2

Took me longer to get the SD card loaded than it took to get the whole rig running. Probably 30 minutes, and some of that was comparing the old 820T receiver to the 820T2 receiver
 
ElPaso Pilot said:
Jim,

Take a look at these links:
http://www.sprut.de/electronic/pic/projekte/adsb/adsb_en.html
http://www.rtl-sdr.com/adsb-aircraft-radar-with-rtl-sdr/
Click to expand...

Ok, and I did, and there is a lot of verbiage to wade through. I now know that the signal is vertically polarized, so now the question arises ... why are a lot of the folks saying that a 5" antenna is desirable when that is nearly half-wave with antenna wire of any reasonable diameter. 2.5" is quarter wave, which as a ground plane antenna is resonant at 1090 MHz. What's the deal with that?

Jim
 
weirdjim said:
Ok, and I did, and there is a lot of verbiage to wade through. I now know that the signal is vertically polarized, so now the question arises ... why are a lot of the folks saying that a 5" antenna is desirable when that is nearly half-wave with antenna wire of any reasonable diameter. 2.5" is quarter wave, which as a ground plane antenna is resonant at 1090 MHz. What's the deal with that?

Jim
Click to expand...

Couple of points. First, you may want to receive both 1090 as well as 978 MHz, for dual band operation. (Single band may reduce the traffic you receive by a half or more.)
Therefore, optimizing the antenna for either frequency may reduce performance in dual band mode.
Second, for quarter wave you'll need (as you say) a ground plane, which may not be readily available in many installations, so half wave to straddle both freqs at around 5.75" (see discussion here) may be the best compromise.
 
RotorDude said:
Couple of points. First, you may want to receive both 1090 as well as 978 MHz, for dual band operation. (Single band may reduce the traffic you receive by a half or more.)
Therefore, optimizing the antenna for either frequency may reduce performance in dual band mode.
Second, for quarter wave you'll need (as you say) a ground plane, which may not be readily available in many installations, so half wave to straddle both freqs at around 5.75" (see discussion here) may be the best compromise.
Click to expand...

Thanks. As usual, there is way too much misinformation on forums as usable information. A half wave in space is antiresonant at the operating frequency. A half wave against a coaxial cable 90° "ground" for the other half of the antenna is also antiresonant.

Bandwidth of antennas is dependent on one primary factor ... the "fatness" of the antenna. The fatter the antenna, the broader the bandwidth. Now to straddle 978 to 1090 is a fractional bandwidth of about 11%, which at this frequency you can easily achieve with an antenna a quarter-inch in diameter or so. You can do it moderately with a #8 fat copper wire if you wish.

Simply saying that a half-wave antenna "straddles" both of the frequencies is absolute hogwash. Halfwave antennas are antiresonant no matter HOW you load them UNLESS you split them in the middle and provide some sort of balancing mechanism ("balun") to make them work 180° out of phase.

What I'm seeing here is what I saw back in the early '60s with the trucker CB craze on usenet telling truckers about antennas that could work Alaska from Florida any time of the day or night.

Only if said trucker was working a 10 kilowatt linear into a 25 dB Yagi antenna, and then not always. It was your girlfriend's hairdresser's boyfriend's aunt Josie's husband Ferd that cobbled something like this up his basement and it worked ... ONCE.

Jim
 
weirdjim said:
[snip]
What I'm seeing here is what I saw back in the early '60s with the trucker CB craze on usenet telling truckers about antennas that could work Alaska from Florida any time of the day or night.

Only if said trucker was working a 10 kilowatt linear into a 25 dB Yagi antenna, and then not always. It was your girlfriend's hairdresser's boyfriend's aunt Josie's husband Ferd that cobbled something like this up his basement and it worked ... ONCE.

Jim
Click to expand...

Oh man! I remember those days. I worked with a (smart) CB hacker. I heard earfuls. I know enough to know I don't know diddly about how antennas actually work.

John
 
weirdjim said:
Thanks. As usual, there is way too much misinformation on forums as usable information. A half wave in space is antiresonant at the operating frequency. A half wave against a coaxial cable 90° "ground" for the other half of the antenna is also antiresonant.

Bandwidth of antennas is dependent on one primary factor ... the "fatness" of the antenna. The fatter the antenna, the broader the bandwidth. Now to straddle 978 to 1090 is a fractional bandwidth of about 11%, which at this frequency you can easily achieve with an antenna a quarter-inch in diameter or so. You can do it moderately with a #8 fat copper wire if you wish.

Simply saying that a half-wave antenna "straddles" both of the frequencies is absolute hogwash. Halfwave antennas are antiresonant no matter HOW you load them UNLESS you split them in the middle and provide some sort of balancing mechanism ("balun") to make them work 180° out of phase.

What I'm seeing here is what I saw back in the early '60s with the trucker CB craze on usenet telling truckers about antennas that could work Alaska from Florida any time of the day or night.

Only if said trucker was working a 10 kilowatt linear into a 25 dB Yagi antenna, and then not always. It was your girlfriend's hairdresser's boyfriend's aunt Josie's husband Ferd that cobbled something like this up his basement and it worked ... ONCE.

Jim
Click to expand...


So, are you going to offer to partner up with Jesse and design the best darn antenna we ever saw? ;)
 
weirdjim said:
Thanks. As usual, there is way too much misinformation on forums as usable information. A half wave in space is antiresonant at the operating frequency. A half wave against a coaxial cable 90° "ground" for the other half of the antenna is also antiresonant.

Bandwidth of antennas is dependent on one primary factor ... the "fatness" of the antenna. The fatter the antenna, the broader the bandwidth. Now to straddle 978 to 1090 is a fractional bandwidth of about 11%, which at this frequency you can easily achieve with an antenna a quarter-inch in diameter or so. You can do it moderately with a #8 fat copper wire if you wish.

Simply saying that a half-wave antenna "straddles" both of the frequencies is absolute hogwash. Halfwave antennas are antiresonant no matter HOW you load them UNLESS you split them in the middle and provide some sort of balancing mechanism ("balun") to make them work 180° out of phase.

What I'm seeing here is what I saw back in the early '60s with the trucker CB craze on usenet telling truckers about antennas that could work Alaska from Florida any time of the day or night.

Only if said trucker was working a 10 kilowatt linear into a 25 dB Yagi antenna, and then not always. It was your girlfriend's hairdresser's boyfriend's aunt Josie's husband Ferd that cobbled something like this up his basement and it worked ... ONCE.

Jim
Click to expand...

I actually saw a CBer using a 5kw lean-ear back in the day.

Technically a half-wave antenna is resonant, and can be matched, but at impedance a that generally are difficult to match & fairly sensitive. It can be done, I've done it, at AM MW stations.There are a bunch of Halfwave AM broadcast antennas put there.

That said, I wouldn't do it at UHF, especially in an environment where the antenna and matching circuit can be used like a theremin.
 
Reporting zero altitude on wingx , known issue ???
 
Scrabo said:
Is it just me but how the hell is the metal antenna meant to screw on to this !!!
Click to expand...


Seen on rtl-sdr.com's website...

"International sales of these units with antennas from the Chinese warehouse are briefly suspended while we fix an issue with damage caused by rough international shipping. If your antennas arrived broken, or the screw on the base was pushed in during transit please contact us at rtlsdrblog@gmail.com and we will refund you the $5 cost of the antennas. Self repair info. Amazon and dongle only units are shipping normally."
 
RotorDude said:
Open source 3D printer instructions for a case for "Stratux" have been published.

http://www.thingiverse.com/thing:990127



Edit: this is for the single band version. The author is planning to release a dual band version soon, per this: https://www.reddit.com/r/stratux/comments/3ivmsf/3dprinted_case_initial_release_singleband_no/
Click to expand...


He's got two layers of the three layer "sandwich" done.

https://www.reddit.com/r/stratux/comments/3iwyya/3d_printable_dual_rtl_gps_case_work_in_progress/

Edit: This is for two SDR plus GPS module.
 
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