ADS-B DIY Antenna

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ab cd

Senior Member
I change it like this , no need for reboot and "dpkg-reconfigure"

Editing dump1090-mutability configuration

Code:
sudo nano /etc/default/dump1090-mutability
look for Gain setting section and change it

# RTLSDR gain in dB.
# If set to "max" (the default) the maximum supported gain is used.
# If set to "agc", the tuner AGC is used to set the gain.
GAIN="agc"

Save file CTRL+O
Enter and exit CRTL+X

Reload config

Code:
sudo /etc/init.d/dump1090-mutability force-reload
or
Code:
 sudo /etc/init.d/dump1090-mutability restart

[ ok ] Restarting dump1090-mutability daemon: dump1090-mutability.

Thanks, your's is easier method than what I did.
 
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xforce30164

Active Member
I just noticed something funny with the metric setting on dump1090 and flightaware. if you for example look at the tracklog of this flight (around 10:23/24 the speed suddenly jumps a lot higher, which is when the aircraft was received by my receiver.),
I think it has to do that the metric speed is parsed as being imperial and that results into a too high result.

track2.png

[time] [lat / lon] [track] [knots] [km/h] [altitude]
track1.png
 

xforce30164

Active Member
http://www.ebay.com/itm/ADS-B-omni-...621?pt=LH_DefaultDomain_0&hash=item2c9779db3d
I would say so far it is picking up more planes then my 8 Legger antenna. From when i looked to see how many planes I was picking up before I changed it out to this antenna. It would be a easy 40 more planes total or more. So It is helping so far. I will see what my stats show. I put it in the same place as the 8 Legger.
Just a quick question about the antenna, I measured mine with an ohm-meter and it showed about 4 ohms, so it is a dc-grounded antenna then. but when I connect it to my dongle (just quick test with coax screwed tight by the nut and centerconductor held in place, I get close to zero messages. it seems like my current dongle doesn't like DC-shorted antennas? Any ideas on why this is happening? (or anyone else any idea?)

also, do you have your antenna connect straight to your dongle or with an amplifier in between?
 

obj

New Member
I just noticed something funny with the metric setting on dump1090 and flightaware. if you for example look at the tracklog of this flight (around 10:23/24 the speed suddenly jumps a lot higher, which is when the aircraft was received by my receiver.),
I think it has to do that the metric speed is parsed as being imperial and that results into a too high result.

View attachment 1226
[time] [lat / lon] [track] [knots] [km/h] [altitude]
View attachment 1227
All speeds in the messages themselves are in imperial, and the data fed to FlightAware is in imperial, so I doubt this is it. (And if it was, I'd expect it to happen consistently for every aircraft you see..)

However note that speeds can be either airspeed or ground speed; the data fed to FlightAware doesn't distinguish the two (though the underlying messages do). If the aircraft changed the report type briefly (e.g. GPS problems) then that might explain it.

(edit: Though that _is_ about a factor of 1.8 you've got there. Huh. Odd.)
 

xforce30164

Active Member
All speeds in the messages themselves are in imperial, and the data fed to FlightAware is in imperial, so I doubt this is it. (And if it was, I'd expect it to happen consistently for every aircraft you see..)

However note that speeds can be either airspeed or ground speed; the data fed to FlightAware doesn't distinguish the two (though the underlying messages do). If the aircraft changed the report type briefly (e.g. GPS problems) then that might explain it.

(edit: Though that _is_ about a factor of 1.8 you've got there. Huh. Odd.)
Hmhm, I'll send an email to flightaware if I can find the correct support/technical-email address and see if they have any idea. I got triggered by the 1.8 factor aswell, if you look at the reports before and after my two reports the knots and kph speeds match quite close.
 

jepolch

Active Member
I wrote to Pinkfroot to let them know about he high CPU load on the Pi when running their feeder software. Here's the response I got.

Thank you for sharing your findings.

We've been running some tests here and agree with you!

We are now working on a new client!
As soon as this is ready I'll send it over.

Thanks as always for sharing.
 

ab cd

Senior Member
I wrote to Pinkfroot to let them know about he high CPU load on the Pi when running their feeder software. Here's the response I got.

Thank you for sharing your findings.

We've been running some tests here and agree with you!

We are now working on a new client!
As soon as this is ready I'll send it over.

Thanks as always for sharing.
I also got their reply :

From: Pinkfroot (support@pinkfroot.com)
Sent: Fri 2/27/15 8:20 AM
To: abcdXXXXXXXXX

Hi ab cd,
Thank you for this feedback.
We have been testing and agree with your findings.
We will work on a new client.
As soon as this is ready I'll get it over to you.

With thanks and best regards,
Mark


>>On Tue, 24 Feb at 5:53 pm , ab cd <abcdXXXXXXXX> wrote:
>>Hi Mark!
>>I have been checking my Raspberry Pi's CPU usage for last few days and found "node" is one of the top user of CPU.
>>Since "node" is exclusively used by PFClient, and poses a heavy burden on CPU, I feel you need to reconsider using it by your data feeder.
>>Here are figures from my last check about 15 minutes ago:
>>CPU USAGE
>>node = 35.7%
>>dump1090 = 34.1%
>>piaware = 1.3 %
>>fr24feed = 1.0 %

>>(Please see screenshot below)
>>Regards
>>ab cd


RPi_CPU_usage.PNG


 
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ab cd

Senior Member
WANT AN EASY-TO-MAKE INDOOR ANTENNA BETTER THAN DONGLE's STOCK ANTENNA?

Here comes the PlateTenna

Collect the Stuff
Tip:
(1) For RG6 coax lengths in excess of 5m/15ft, coax attenuation will be high, and an amplifier may become necessary.
(2) Even with short lengths of Coax, use of amplifier increases plane count & range.

F to MCX Pigtail+RG6 Coax.PNG DSC03542-R.JPG

Assemble the Platenna
The whip at top is ¼ wavelength (68mm)

DSC03544-R.JPG DSC03545-R.JPG

Trial Run/Performance:
Range Rings are 50nm apart. The outermost ring has a radius of 300nm

DSC03547-R.JPG Platetenna 72 hrs run 27 Feb 2015.PNG
 
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DougJohnson

New Member
Here comes the PlateTenna
Here's my latest antenna experiment. A Franklin based on this: http://www.tech-software.net/1090_ant_02.JPG

It's our old standby, 12 gauge copper wire on a SO-239 attached to 10" pie pan. The holes in the pie pan are to reduce the wind load. I'm only 24 hours into testing it, but it seems to be worse than the spider. I'll post a full report after 48 hours of running.

In theory, it should be about 4.8 db better than the spider, but so far, it doesn't look like it. I made it very carefully, measuring lengths with a caliper. Sigh.

-- Doug
 

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ab cd

Senior Member
Here's my latest antenna experiment. A Franklin based on this: http://www.tech-software.net/1090_ant_02.JPG

It's our old standby, 12 gauge copper wire on a SO-239 attached to 10" pie pan. The holes in the pie pan are to reduce the wind load. I'm only 24 hours into testing it, but it seems to be worse than the spider. I'll post a full report after 48 hours of running.

In theory, it should be about 4.8 db better than the spider, but so far, it doesn't look like it. I made it very carefully, measuring lengths with a caliper. Sigh.

-- Doug
(1) Sigh... You are knocked down by a Collinear as is common experience!
(2) Your antenna is Coiled Collinear, NOT Franklin Collinear (Franklin has hairpins, not coils).
 

DougJohnson

New Member
(1) Sigh... You are knocked down by a Collinear as is common experience!
They look so easy. This is my second so-so collinear. I did an 8 segment out of RG-6. It was better than the little stub included with the dongle, but not nearly as good as the spider. I've got some RG-58 I might try if I want to keep beating my head against the wall.

(2) Your antenna is Coiled Collinear, NOT Franklin Collinear (Franklin has hairpins, not coils).
You're right. Thanks.
-- Doug
 

Sjacket99

Member
Just a quick question about the antenna, I measured mine with an ohm-meter and it showed about 4 ohms, so it is a dc-grounded antenna then. but when I connect it to my dongle (just quick test with coax screwed tight by the nut and centerconductor held in place, I get close to zero messages. it seems like my current dongle doesn't like DC-shorted antennas? Any ideas on why this is happening? (or anyone else any idea?)

also, do you have your antenna connect straight to your dongle or with an amplifier in between?

I am using this dongle with the eBay antenna.. http://amzn.com/B00P2UOU72
I never ran a amp or anything yet with any antenna. When I replaced my 8 Legger spider antenna with this antenna from eBay I got a instant 40-60 more planes being tracked from what I was getting at the time. So it is helping me out pretty good.

If you look at the picture I added from date 2/15 to 2/24 thats from the 8 Legger and from 2/25 and on is from the antenna from eBay.. I put the new antenna from eBay in the same place with the same cable and dongle..
 

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bramj

Member
Last week i used the franklin-antenna inside , yesterday i placed it outside ...
Max range without amplifier 184nm, at peak moments over 1100 mesg/sec

FullSizeRender.jpg


Nice increase in hits and positions

Screen Shot 2015-02-28 at 08.15.37.png


Screen Shot 2015-02-28 at 08.15.14.png


Screen Shot 2015-02-28 at 08.09.32.png


Screen Shot 2015-02-27 at 18.50.04.png
 
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ab cd

Senior Member
Last week i used the franklin-antenna inside , yesterday i placed it outside ...
Max range without amplifier 184nm, at peak moments over 1100 mesg/sec

View attachment 1240

Nice increase in hits and positions

View attachment 1243

View attachment 1244

View attachment 1241

View attachment 1242
Congratulations! Great Range without amplifier.
Of all the Collinears, Franklin is the least tricky. The main difficult dimension is the gap between two parallel wires of stub (hairpin), which though narrow, is not so difficult to achieve.
 

DougJohnson

New Member
Last week i used the franklin-antenna inside , yesterday i placed it outside ...
Max range without amplifier 184nm, at peak moments over 1100 mesg/sec
Could you describe how you have it hooked up? Do you, or anyone, know the impedance of the antenna?
Thanks,
Doug
 

jepolch

Active Member
Here's my latest antenna experiment. A Franklin based on this: http://www.tech-software.net/1090_ant_02.JPG

It's our old standby, 12 gauge copper wire on a SO-239 attached to 10" pie pan. The holes in the pie pan are to reduce the wind load. I'm only 24 hours into testing it, but it seems to be worse than the spider. I'll post a full report after 48 hours of running.

In theory, it should be about 4.8 db better than the spider, but so far, it doesn't look like it. I made it very carefully, measuring lengths with a caliper. Sigh.

-- Doug
I had the same issue. I thought I had cut it precisely, but apparently not.
 

jepolch

Active Member
For some reason I don't seem to be getting updates from the forum anymore. I checked it and found you guys had been chatting away for a couple of days and I wasn't notified. :( I made this filter and have been experimenting with it. It works, but it's hard to know how well. It's shorted, so I can't put it on either of my antennas at this time. When the snow clears off the roof I'll put it up, but I need to add a DC blocker after the amp and then connect the filter to the antenna. Plans are here: http://www.w6pql.com/microwave_filters.htm
 

Attachments

Sjacket99

Member
For some reason I don't seem to be getting updates from the forum anymore. I checked it and found you guys had been chatting away for a couple of days and I wasn't notified. :( I made this filter and have been experimenting with it. It works, but it's hard to know how well. It's shorted, so I can't put it on either of my antennas at this time. When the snow clears off the roof I'll put it up, but I need to add a DC blocker after the amp and then connect the filter to the antenna. Plans are here: http://www.w6pql.com/microwave_filters.htm

Nice.. Good job..
 
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