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Stratus wanna-be (Stratux)

emuyshondt said:
The datasheet for the Skyguard antenna is at https://www.linxtechnologies.com/resources/data-guides/ant-916-cw-hwr.pdf and says the antenna is recommended for 900 to 930 MHz. It has a pretty sharp VSWR curve that is at a minimum just below 916MHz. If tha antenna works well, the other one I posted should look even better. I haven't tried either, though, and Skyguard seems to get enough performance out of theirs.
Click to expand...

Let me know your findings between the two antennas
 
I ordered the stub antenna. I may also try the Linx Technology (Skyguard) later on. I actually ordered it from Skyguard, but they refunded my money yesterday and told me to go get it from DigiKey. I'm traveling for a few weeks so it will have to wait until after I get back and try things with the stuff I already got. I don't have any measurement equipment to give detailed answers, though.

I thought maybe there are some RF gurus here that might know the answer without me having to buy a lot of hardware.

One thing I will try is running two receivers 978 and 1090MHz), with a splitter and a single antenna. I have the parts to do that waiting for me.
 
More data....

While I would encourage others to experiment, I have been doing some test flights and am happy to report that science works and I am finding the best over all results with one antenna just under 3 in long feeding both SDR sticks.

This antenna consistently pulls in the same number of towers as the GDL sitting next to it on the dash, is compact, and seems to work pretty well on both bands.

I still get better reception on 978 with an extended antenna on my back porch, but I don't fly there very often, so I am gonna ask that people ignore my previous post (for those of you who don't ignore all of my posts already.....)


petehowell said:
I took a quick and dirty sample of 978 UAT data tonight using the IFLY data rate dialog. One tower only from the comfort of my back porch. The data seems to support what I saw in the plane today - that a longer antenna with length of ~7.75-8.25 inches from transition of plastic base to metal antenna provides a better data transfer rate.

Methodology - Antenna length was set and then data taken at 10 sec intervals for 4 intervals.

I'll try it again later - not intuitive at all...happy to be proven wrong

Stratux%252520Data%252520Rate.jpg


Stratux%252520Data%252520Rate%252520Graph.jpg
Click to expand...
 
petehowell said:
I am finding the best over all results with one antenna just under 3 in long feeding both SDR sticks.
Click to expand...

Pete, if you don't mind, would you post a picture of your antenna? Also, when you say "feeding both SDRs" would you share what you did to share the antenna?

Thanks for your contributions!
 
Sure thing!

I'll try to grab it at lunch and post some pics. My daughter dubbed it the "killer bee".


humptybump said:
Pete, if you don't mind, would you post a picture of your antenna? Also, when you say "feeding both SDRs" would you share what you did to share the antenna?

Thanks for your contributions!
Click to expand...
 
Killer Bee.....

humptybump said:
Your daughter should be in marketing :)
Click to expand...

Here you go!

IMG_20150915_105200273_HDR.jpg


Lunch time cell phone greatness!

IMG_20150915_105218590.jpg


Printed case from a clever Reddit guy. 2x $1.43 usb extensions. Velcro strap from the bottom of my desk drawer. Yes - those are Legos as spacers........ The antenna is from the $12 SDR stick chopped to ~3" with 2 cables run into the base and soldered. Will probably incorp a small fan at some point. Antenna might get a bit shorter, but works pretty well. (5 Towers at 1000AGL just north of Minne. and good ES coverage of the big boys upstairs)

Clearly, this design is an acquired taste. Proceed with your giggling - I can handle it! My wife says it needs a sign that says "NOT A BOMB!"
 
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petehowell said:
Here you go!

IMG_20150915_105200273_HDR.jpg


Lunch time cell phone greatness!

IMG_20150915_105218590.jpg


Printed case from a clever Reddit guy. 2x $1.43 usb extensions. Velcro strap from the bottom on my desk drawer. Yes - those are Legos as spacers........ The antenna is from the $12 SDR stick chopped to ~3" with 2 cables run into the base and soldered. Will probably incorp a small fan at some point. Antenna might get a bit shorter, but works pretty well. (5 Towers at 1000AGL just north of Minne. and good ES coverage of the big boys upstairs)

Clearly, this design is an acquired taste. Proceed with your giggling - I can handle it! My wife says it needs a sign that says "NOT A BOMB!"
Click to expand...

It doesnt have a red flashing light or countdown clock, no bleep bleep sounds so acording to my TV research... Its not a bomb
 
Yes Sir

Leland said:
Pete, when you see the "big boys upstairs", can you also see the little boys below them, when you are close enough?
Click to expand...

I am getting good coverage on 978 and 1090. WX data is streaming in, I see the local traffic nearby and airliners up top.

image-3.png
 
More fun!

Some people ask why a J-Pole.....I Ask, Why NOT!

Easy build and it rocked on 978Mhz! Some scrap plexi, copper tape and a little math! It opens up the possibility of a flexible antenna that could be incorporated into the canopy as well ......

IMG_6280.JPG


IMG_6282.JPG


More to come.....
 
petehowell said:
I am getting good coverage on 978 and 1090. WX data is streaming in, I see the local traffic nearby and airliners up top.
Click to expand...

But do you see all the local traffic when the airliners are overhead, or do you only see ADS-B Out equipped local traffic?
 
Forgot about that...

petehowell said:
Some people ask why a J-Pole.....I Ask, Why NOT!

Easy build and it rocked on 978Mhz! Some scrap plexi, copper tape and a little math! It opens up the possibility of a flexible antenna that could be incorporated into the canopy as well ......

IMG_6280.JPG


IMG_6282.JPG


More to come.....
Click to expand...

I said I had only played with end-fed half wave antennas at HF, but I forgot about my homebrew J-poles for 2m and 440 fast-scan TV. :eek:

Great idea! Just hate to see it attached to RG-174 or similar with losses of 1dB/inch :D at 900MHz. Well, maybe not quite that bad. Best to mount the receiver right at the antenna and ditch the feedline if you can.

Like I said, awesome geeky thread. Carry on.

-Stormy
 
ADS-B Out

Hi Leland,

I see all the traffic if it is in the system b/c I am ADS-B out equipped.

So I am seeing 978 out planes, 1090 out planes, and radar targets that are rebroadcast to me as an out equipped plane.

If I have misunderstood your question, let me know.

Leland said:
But do you see all the local traffic when the airliners are overhead, or do you only see ADS-B Out equipped local traffic?
Click to expand...
 
bad coax

Yes the coax is a joke - thus the small runs on "The Bee" blahahaha


Bill Boyd said:
I said I had only played with end-fed half wave antennas at HF, but I forgot about my homebrew J-poles for 2m and 440 fast-scan TV. :eek:

Great idea! Just hate to see it attached to RG-174 or similar with losses of 1dB/inch :D at 900MHz. Well, maybe not quite that bad. Best to mount the receiver right at the antenna and ditch the feedline if you can.

Like I said, awesome geeky thread. Carry on.

-Stormy
Click to expand...
 
J-Pole

Tested the Jpole vs the stock antenna tonight. Jpole pulls data from the 1 ground station from my back porch very well - the stock antenna did not at all. Looks to be promising for further development!

Screen cap video tells the story. Log files being analyzed.
 
yeah, you did

;)

humptybump said:
stormy, I used one of the online "calculators" and came up with about "0.35 dB" loss at 978Mhz for 12 inches of RG-174. Did I make a mistake?
Click to expand...

You missed my tongue-in-cheek. It's all good.

Point it, it works - and apparently, very well.
 
Stratux and Fltplan on Nexus

During my flight testing with Stratux using Fltplan GO on an Android Nexus I was disappointed to discover that the GPS function did not work any longer. I have been using FLtplan GO as a backup of my Skyview and I program all my flights in Skyview and Fltplan GO. All other functions of Stratux (Weather and Traffic) are working but when ADS-B is on my map is no more moving on Nexus.
Here is what support at Fltplan answered on this matter:

"This is because Stratux does not have built in GPS and at this time our app does not support separate ADS-B and GPS receivers.
We will be making changes to the programming in the next couple weeks so that you can separate the two out. ".

It looks like Fltplan is going to do something about it soon. I hope so else it would be a big incentive to switch to another application on a different type of tablet.
 
New beta version posted today..

Auto configure RY835AI GPS over serial port.
Added support for different GPS sentences.
 
I want to upgrade to one of the new beta releases, but the notes indicate that the logging is turned on and will fill up the memory card with data. Does anyone know how to turn off the logging? There was mention of a console, but I have never used a console for this program. I burned it to the SD card and it self boots on the Raspberry. Also happy to lock the card or create a partition as they suggeted, but don't know how to do that.

Thanks for any help you can offer.

Larry
 
Hi Larry - I've been playing around some with the beta builds, both from the image and building from source. I'm not as proficient as the people doing the coding, but as far as I can tell, the only way to turn the logging on or off at this point is when the software is compiled. Even with the logging on, though, it would still take the stratux several hours to accumulate a log large enough to fill up the micro SD card.

If you are able to connect a console (like Terminal in OS X) to the RPi with an ethernet cable, you can try logging in with something like "ssh [email protected]" (that's the default IP address, AFIK). The default password is raspberry. If you get logged in OK, you can try looking at the logs with "ls -al /var/log". You'd see a listing of the log files for the RPi, including a few for the stratux. You can try deleting the UAT log (the one that would grow the fastest with a single SDR antenna) with "sudo rm -f /var/log/stratux-uat.log". Then do "ls -al /var/log" to see if the UAT log has in fact gone away. You'd probably have to restart the Rpi to get stratux happily running and logging away again (restart it with "sudo shutdown -r 0"), but I'm not sure if it needs the restart.

As I said, I'm learning this as I go, so YMMV! I've started over from scratch on the SD card a few times while experimenting...!
 
NM Doug said:
Hi Larry - I've been playing around some with the beta builds, both from the image and building from source. I'm not as proficient as the people doing the coding, but as far as I can tell, the only way to turn the logging on or off at this point is when the software is compiled. Even with the logging on, though, it would still take the stratux several hours to accumulate a log large enough to fill up the micro SD card.

If you are able to connect a console (like Terminal in OS X) to the RPi with an ethernet cable, you can try logging in with something like "ssh [email protected]" (that's the default IP address, AFIK). The default password is raspberry. If you get logged in OK, you can try looking at the logs with "ls -al /var/log". You'd see a listing of the log files for the RPi, including a few for the stratux. You can try deleting the UAT log (the one that would grow the fastest with a single SDR antenna) with "sudo rm -f /var/log/stratux-uat.log". Then do "ls -al /var/log" to see if the UAT log has in fact gone away. You'd probably have to restart the Rpi to get stratux happily running and logging away again (restart it with "sudo shutdown -r 0"), but I'm not sure if it needs the restart.

As I said, I'm learning this as I go, so YMMV! I've started over from scratch on the SD card a few times while experimenting...!
Click to expand...

Thanks for the guidance Doug. I will try some of these suggestions. Do you know if the log deletes itself after shut down or will it keep collecting? If the latter, when the disk gets full, will Statux still run or does it need free space to do things? I don't get why the developers would turn this on, knowing that users will have to take proactive steps to keep the system running. That seems inconsistent with their philosophy on this project.

Larry
 
Minne to Madison Antenna Comparison

Had 3 hrs in the plane today to do comparisons. The J-pole always picked up more ground stations and traffic than the ~3" stub antenna, but is harder to package in the plane. When you are are 4500 ft, they both work pretty well.

I'l continue to experiment.......
 
humptybump said:
Hi Larry,

If you are comfortable with SSH to access the Raspberry Pi while it's running and if you can use "vi" or "nano" to edit the file /etc/stratux.conf then you can turn logging on/off that way without touching the code.

The content of the config file are shown in this other thread:

https://www.reddit.com/r/stratux/comments/3l84cm/calibrating_the_rtlsdr_dongle/

You want to set ReplayLog to false.
Click to expand...

Thanks Glen. I can figure out SSH, but I don't have a mac or linux, so not sure how to edit the file yet. Can I delete the log file via SSH? Also, can I edit the config file while the SD card is in my windows machine or is this config file programmatically create at run time?

Larry
 
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WingedFrog said:
During my flight testing with Stratux using Fltplan GO on an Android Nexus I was disappointed to discover that the GPS function did not work any longer. ...

Here is what support at Fltplan answered on this matter:

"This is because Stratux does not have built in GPS and at this time our app does not support separate ADS-B and GPS receivers.
We will be making changes to the programming in the next couple weeks so that you can separate the two out."
Click to expand...

Interesting, and good to know as I am running FltPlanGo on Android as well. It does make me wonder though: Could you plug in a GPS antenna to the Stratux and include the GPS data that way? One of the benefits of the Stratus/Dual/etc. units is that it's also a GPS, so you can ensure good signal regardless of where the tablet is in the cockpit... Maybe it's an option for Stratux?
 
Stratux has beta level support for GPS. As development continues, it will have full support for a GPS/AHRS module that adds about $45 to the cost. You can read about current beta testing experience over on the reddit subgroup.
 
Delta Pop & Stratux - Wow!

No surprise to many VAFers, but Don P's Delta Pop antenna is a big winner with Stratux! I made a quick and dirty 2X - MCX to BNC splitter cable by jamming 2 RG174 cables into an RG58 BNC. This can't be legal...... what the heck, give it a try!

Well, this is what I saw on the ground at KANE......No towers are available on the ground at KANE.....
Screenshot_2015-09-21-18-27-37.jpg


At 1000 AGL I had 5 towers and crazy data rates....
Screenshot_2015-09-21-18-34-43.jpg


A video of the action - sorry about the music - it was better than loud engine noise.

The stock antenna and the jpole work OK, but the Delta Pop is crazy good.
 
humptybump said:
Stratux has beta level support for GPS. As development continues, it will have full support for a GPS/AHRS module that adds about $45 to the cost. You can read about current beta testing experience over on the reddit subgroup.
Click to expand...
Well, alrighty then... Guess i'd better look at placing an order from Amazon... :)
 
is this the antenna you are referring to?
http://www.deltapopaviation.com/UAT_Antenna.html



petehowell said:
No surprise to many VAFers, but Don P's Delta Pop antenna is a big winner with Stratux! I made a quick and dirty 2X - MCX to BNC splitter cable by jamming 2 RG174 cables into an RG58 BNC. This can't be legal...... what the heck, give it a try!

Well, this is what I saw on the ground at KANE......No towers are available on the ground at KANE.....
Screenshot_2015-09-21-18-27-37.jpg


At 1000 AGL I had 5 towers and crazy data rates....
Screenshot_2015-09-21-18-34-43.jpg


A video of the action - sorry about the music - it was better than loud engine noise.

The stock antenna and the jpole work OK, but the Delta Pop is crazy good.
Click to expand...
 
New beta posted : v0.3b4



GPS message replay log.
UAT signal strength logging.
/var/log/stratux.log - added periodic status updates (CPU temp, GPS info, etc.)
Improved queue/memory management.
Go1.5.1 (dev).
 
My 3D Printed Stratux Case

I designed and printed my own totally self-contained Stratux case, simply plug in the micro-USB power cord and go flying.

My design has a cooling fan and I printed it with ABS plastic so it should survive summertime use on the glare-shield. A couple strips of velcro will hold it in place.

The reception is great, I was receiving 10 978Mhz towers and over 6,000 1090es messages while cruising at 1,000" AGL.

See more details in my Reddit post at Stratux Case.

More photos are at http://imgur.com/gallery/bS2gD/new.

And get my 3D STL files and build instructions at http://www.thingiverse.com/thing:1013857.

Now I need to tinker with a j-pole antenna design to incorporate into the case.

dK16BBb.jpg


EEw2wYK.jpg


35dbcOA.jpg

Notice - the portable battery on top of the box is not good for built-in GPS reception - this was a test flight of ADS-B reception only. It will be plugged into a 2.5A cigarette adapter plug for normal use.
 
Nice!

Sweet build, my friend. Don't hesitate to hit me up if I can help with the J-pole.

Tony Kirk said:
I designed and printed my own totally self-contained Stratux case, simply plug in the micro-USB power cord and go flying.

My design has a cooling fan and I printed it with ABS plastic so it should survive summertime use on the glare-shield. A couple strips of velcro will hold it in place.

The reception is great, I was receiving 10 978Mhz towers and over 6,000 1090es messages while cruising at 1,000" AGL.
Click to expand...
 
would a jpole antenna be better than the deltapop antenna?

Where would one mount the deltapop UAT? I would guess under the AC someplace as close to the receiver to avoid single loss as much as possible without interfering with under fuse mounted comm antennas..


petehowell said:
Sweet build, my friend. Don't hesitate to hit me up if I can help with the J-pole.
Click to expand...
 
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I found the Jpole better than the stock dongle antenna, but the delta pop with the airframe as ground plane was even better.

Not a lot of testing - YMMV.....


moll780 said:
would a jpole antenna be better than the deltapop antenna?

Where would one mount the deltapop UAT? I would guess under the AC someplace as close to the receiver to avoid single loss as much as possible without interfering with under fuse mounted comm antennas..
Click to expand...
 
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