ADS-B DIY Antenna

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airbus340

New Member
One thing tho that is a lot different with the plate antenna compared to all other homebrew is that is it giving me much better signal strength.
Dump1090 show 20-50 with all other antennas but the plate antenna is up to 170 on some planes. :)

But the message rate is still low, VRS show about 10 per update on the numbers and with the stacked dipole I get 30 numbers between every update. (1 second between the updates I think)
 

ab cd

Senior Member
Thank you, then I have measured correctly. Yes, they are electrically connected as the Belling Lee is flat from where the cable connects, so the flat part is what the plate is resting on.
Good. Here is another photo for whip dimensions of the Belling Lee
Belling Lee Whip.PNG

Info for North American members:
The Belling-Lee connector, known commonly as TV aerial plug, TV antenna connector or simply an antenna plug, is the traditional RF connector for European and Australian TV sets and FM / DAB-radio receivers that connects them to a terrestrial VHF/UHF roof antenna. It was Invented at Belling & Lee Ltd in Enfield, United Kingdom around 1922 at the time of the first BBC broadcasts
 
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jepolch

Active Member
Thanks for the tip.
You were right that with a diplexer it didn't work.
But I found a 2 way splitter with power pass on both ports, 5-2500MHz, and it seems to work. Without amp my antenna was picking 0 planes, but when I put amp, instantly picked a plane and dump1090-muta show's RSSI around -3, so it clearly works somehow. (That's the only plane in possible range here)

It's pretty silent planewise around here so I can't really say how much it will improve my range yet. We'll see..

Photo of the splitter and amp attached.
Have you looked at your area using the main PlaneFinder or FlightRadar24 site to see how many planes they show? If they show more than you are seeing, then you know your goal.
 

juha

New Member
Have you looked at your area using the main PlaneFinder or FlightRadar24 site to see how many planes they show? If they show more than you are seeing, then you know your goal.

I have. My location currently is very much blocked, antenna is in my balcony which is facing south, and there's trees just front so I can't really see much sky. That's why my max range is without amp 100nm, with amp & two way splitter 140nm. With LNA4ALL (which got burned somehow, waiting for new MMIC component from adam) I got about 220nm.
After I'm satisfied with my antenna and configuration, I'm going to move my feeder to another location which has unobstructed view to all directions.

I'm going to try ab cd's homebrew injector tomorrow, unfortunately the shop is closed for today so can't get the components today.
 

ab cd

Senior Member
I am now trying a plate antenna ........... The Belling Lee is about 10mm high I think.
One thing tho that is a lot different with the plate antenna compared to all other homebrew is that is it giving me much better signal strength.
Dump1090 show 20-50 with all other antennas but the plate antenna is up to 170 on some planes. :)

But the message rate is still low, VRS show about 10 per update on the numbers and with the stacked dipole I get 30 numbers between every update. (1 second between the updates I think)
Try these while the plate antenna is still in balcony at your arms reach - no roof climbing.
(1) Lower the Belling Lee as much as you conveniently can, so that the start point of whip comes nearer to the Plate, and check whether or not it improves reception.
(2) Trim the Whip, 2 mm at a time, 3 or 4 times. Check reception after each trimming.
 

ab cd

Senior Member
Testing 12 elements coax colinear :)

180 nm

View attachment 1912


PH-lab - http://nl.wikipedia.org/wiki/PH-LAB

Fly's nice circle around schiphol Airport.:)

View attachment 1911

View attachment 1913
1000 msg/sec wow!
My system's peak is around 350 msgs/sec, but my max range is good - 450 kms/250 nm.
My System: cantenna or spider or platetenna, no amplifier, 12 ft/4 m coax between antenna & DVB-T dongle.

EDIT:
Added Max Range & Msg/sec curves...Current antenna is 4-legged Spider.

dump1090-rpi-range-24h-07May.png


dump1090-rpi-rate-24h-07May.png


dump1090-rpi-acs-24h-07May.png

 
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jepolch

Active Member

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jepolch

Active Member
This is a long shot, I know, but maybe someone can help with this. I'm running Rpimonitor and I converted the temperature to F. Now the temp is displayed to four decimal places. That's kinda overkill! Can anyone tell me what I need to do to modify this configuration to show no decimal places, just the number to the lest of the decimal? Code is attached.
Code:
########################################################################
# Extract CPU Temperature information
#  Page: 1
#  Information               Status     Statistics
#  - cpu temperature         - yes      - yes
########################################################################
dynamic.12.name=soc_temp
dynamic.12.source=/sys/devices/virtual/thermal/thermal_zone0/temp
dynamic.12.regexp=(.*)
dynamic.12.postprocess=sprintf("%.0f",$1/1000)*1.8+32
dynamic.12.rrd=GAUGE

web.status.1.content.4.name=Temperature
web.status.1.content.4.icon=cpu_temp.png
web.status.1.content.4.line.1=JustGageBar("Temperature", "°F", 90, data.soc_temp, 180, 100, 80)

web.statistics.1.content.8.name=Temperature
web.statistics.1.content.8.graph.1=soc_temp
web.statistics.1.content.8.ds_graph_options.soc_temp.label=Core temperature (°F)

Edit: I located the answer to my question. For anyone interested in trying this I changed the line of code above to one that sometimes shows only the temp or sometimes the temp with 1 decimal. I don't know why it doesn't strictly obey the rules. I tried to bolden the type of the changed lines, but "code" won't let me do that. This is the line:
dynamic.12.postprocess=sprintf("%.0f",$1/1000)*1.8+32
 

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loplo

New Member
I don't want to be rude, but what about opening a specific thread for this?
It has absolutely nothing to do with the antenna and with this topic.
Lee told us to keep on-topic.
 

ab cd

Senior Member
Below are two graphs over exactly same period
(1) 24 hrs message rate
(2) 24 hrs CPU usage
The message rate is fluctuating considerably, nealy zero at start of graph (left), high for major portion, then again nearly zero at end at right side.

The CPU usage by demodulator (dump1090-mut) is constant throughout the period.

Question:
When the message rate is nearly zero (left and right of graph), what for dump1090-mutability continues to use same amount of CPU as it uses during peak message rate?

08may-dump1090-rpi-rate-24h.png


08may-dump1090-rpi-cpu-24h.png


 

caius

Member
It still has to examine the radio signal to see whether what it is seeing is a valid signal, whether one is there or not. Random noise will produce what looks like message preambles which it then has to assess to see if they are really messages.
 

jepolch

Active Member
Wow! I'm jealous. :D We have maybe a half-dozen airports in the US which are as busy as Schiphol. They are spread across the country.
 

ab cd

Senior Member
My RPi B+ with fresh install of software (Raspbian Wheezy+dump1090-mutability+collectd rrd) has completed 2 days crash-free run. I have not installed any data feeder software. I will keep it running for one week like this.

Actually I am suspecting dump1090-mutability's crashes are caused by one of the data feeders, particularly FR24 feeder. The FR24 feeder installation .deb file includes dump1090 Malcolm Robb version. I am suspecting that when FR24 installer runs, its dump1090 component affects dump1090-mutability, and then dump1090-mutability starts crashing. If the RPi without data feeders does not crash for one week, I will install FR24 data feeder, and then run the RPi for few days to see what happens.

Has anyone of you installed FR24 feeder AFTER installing dump1090-mutability?
 

jepolch

Active Member
My RPi B+ with fresh install of software (Raspbian Wheezy+dump1090-mutability+collectd rrd) has completed 2 days crash-free run. I have not installed any data feeder software. I will keep it running for one week like this.

Actually I am suspecting dump1090-mutability's crashes are caused by one of the data feeders, particularly FR24 feeder. The FR24 feeder installation .deb file includes dump1090 Malcolm Robb version. I am suspecting that when FR24 installer runs, its dump1090 component affects dump1090-mutability, and then dump1090-mutability starts crashing. If the RPi without data feeders does not crash for one week, I will install FR24 data feeder, and then run the RPi for few days to see what happens.

Has anyone of you installed FR24 feeder AFTER installing dump1090-mutability?
Yes, I've been running a Pi 2 since April 11 with the following:

Wheezy
Piaware
FR24feed (installed by deb)
Pfclient
Dump1090-mutability

I haven't had any problems with dump-mut crashing. I just looked on my Pi 2 and in /etc/init.d there is no script that can start up the copies of dump1090 that get installed in /usr/lib/fr24. There are actually two of them - dump1090 and mr-dump1090. Neither one of them has ever started.

When I installed FR24feed from the deb file it asked which version of dump1090 I was using. I answered Malcolm Robb dump1090.
 
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