ADS-B DIY Antenna

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xforce30164

xforce30164

Active Member
radiostationx said:
Hi xforce,
In short..It looks like an SMD, In the few meetings we have had in the last 15 yrs or so,I cannot say we (Myself and SMDs) "get along".:mad: I am not equiped with boinic sight..Over and out !
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That's true, I never used them before, and not sure If I will be using this one anytime soon :p first enough other things to try and experiment with!

ETA:
When I'm back in Eindhoven, first thing I'll do is replace the ebay-antenna with the spider antenna. when I switched them on 1-4 (from spider to ebay antenna) I went from 331k messages to around 100k messages currently with the ebay antenna.
antenna_swap.png
 
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jepolch

jepolch

Active Member
radiostationx said:
1/4 wave 8 leg ground plane F connector Spider Experiment.

4 horizontal + 4 @ 45/60 deg. Centre element from some stripped down Webro WF100 coax core + dielectric.
A very apt backdrop in the photo too ! ;)

A bit too extravagant on materials here but what the heck, I pulled out all the stops here and threw caution to the wind.
I used one of my brand new F connectors.:)

From all the stuff on this thread, I bet some savvy people could flip a nice profit on fleabay or suchlike.
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I'm actually running that exact (well, as close as I can to exact) configuration on one of my spiders. 4X90* and 4X45*. I didn't see any change at all compared to 8X45*. That's my second spider that's always 15-20% than my better spider. I moved the radials to that configuration to see if it would help or hurt. No change.

Edit: Yours was cheaper and easier to make than mine. :)
 
jepolch

jepolch

Active Member
I didn't take a picture after I modified the spider with 4 horizontal radials, but it's the one on the right in this picture. Also, another 8-legged spider that I didn't make, but who appeared in my yard. ;)
 

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ab cd

ab cd

Senior Member
jepolch said:
I didn't take a picture after I modified the spider with 4 horizontal radials, but it's the one on the right in this picture. Also, another 8-legged spider that I didn't make, but who appeared in my yard. ;)
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The "microscopic" inspection of garden spider revealed it is 6-legged, not 8-Legged: 3 legs on right-side & 3 legs on left-side.
A beautiful creature - reminds the greatness of The Creator!
 
jepolch

jepolch

Active Member
ab cd said:
The "microscopic" inspection of garden spider revealed it is 6-legged, not 8-Legged: 3 legs on right-side & 3 legs on left-side.
A beautiful creature - reminds the greatness of The Creator!
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We get some big spiders here. Never saw one that color before. She was made up for Halloween. :)
 
jepolch

jepolch

Active Member
I don't know if you guys read the FlightAware forum, but a while back a guy was talking about using a satellite diplexer as a high pass filter. I bought two of them and have been using one one one of my spiders while watching the other antenna to see how they compare. I have the filter on my better performing spider. You may remember that I said the "worse" antenna was about 15% worse than the better one. Since I installed the filter on the better one, the "worse" one is now 20% worse. Coincidence? I don't know. All I know is that the better one seems to have improved over the worse one and it certainly hasn't hurt the better one. Hey, if you're looking for a cheap high pass filter, try a couple of these. Your results might be even better than mine. I live out in the country and don't have an overwhelming amount of GSM noise - although there is some. I got TWO of these for $5 on Amazon. http://smile.amazon.com/gp/product/B00684D77A
 
giacomo1989

giacomo1989

Member
jepolch said:
I don't know if you guys read the FlightAware forum, but a while back a guy was talking about using a satellite diplexer as a high pass filter. I bought two of them and have been using one one one of my spiders while watching the other antenna to see how they compare. I have the filter on my better performing spider. You may remember that I said the "worse" antenna was about 15% worse than the better one. Since I installed the filter on the better one, the "worse" one is now 20% worse. Coincidence? I don't know. All I know is that the better one seems to have improved over the worse one and it certainly hasn't hurt the better one. Hey, if you're looking for a cheap high pass filter, try a couple of these. Your results might be even better than mine. I live out in the country and don't have an overwhelming amount of GSM noise - although there is some. I got TWO of these for $5 on Amazon. http://smile.amazon.com/gp/product/B00684D77A
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With mine I still get gsm signals which are over 950 Mhz but I've to say that my noise
floor in the adsb band is very low in amplitude .

I've mounted it 2 meters far from the dongle and I still have some FM power cause the cable acts as an antenna!

I've also closed terrestial input with a cap and a 100 ohm resistance which is better (hope) than living it opened!
IMG-20150404-WA0005.jpg
 
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jepolch

jepolch

Active Member
giacomo1989 said:
With mine I still get gsm signals which are over 950 Mhz but I've to say that my noise
floor in the adsb band is very low in amplitude .

I've mounted it 2 meters far from the dongle and I still have some FM power cause the cable acts as an antenna!

I've also closed terrestial input with a cap and a 100 ohm resistance which is etter (hope) than living it opened!
View attachment 1566
Click to expand...
When you said "I've mounted it" do you mean a filter or diplexer?
 
xforce30164

xforce30164

Active Member
jepolch said:
It certainly looks good. How does it compare to a conventional spider?
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It seems to catch more planes, and get slightly higher msg rate, but need to do some more testing.

I also tried the 5/8L active + 4 5/8L radials, didn't work, (too much noise i guess), 5/8L active with 4* 1/4L radials didn't work either, back to 1/4L + 4*1/4L, working nice again. (Also @jepolch, your trick of twisting the wire really helps stiffen it up a touch and straighen it out, before I was rotating it and sliding side of the grip of my wire-cutter along it to straigthen it, having mis-interpreted it, but now I just grabbed one end of the copper wire with pliers, twisted the other end with a power-drill/cordless screwdriver combo and it works like a charm!)

ETA: I've moved the ebay-bought antenna up slightly, number of planes and messages increased noticably, now I'll need to wait and see in the next few days if it is a significant change overal (and not just that it was busier than normal with airplanes when I moved the antenna).

ATM i'm getting the following:
Ebay Antenna: 43Planes 260MSg/sec
1/4L twisted Spider: 31 planes 75Msg/sec
Triangle Spider: 39 planes 220/sec

the ebay antenna is higher than the other two though.

ETA: getting busy, trianglespider picked up 50 planes @ 280msgs/sec just now,
ebay antenna is also around 50 planes on roughly 300 msgs
 
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jepolch

jepolch

Active Member
xforce30164 said:
It seems to catch more planes, and get slightly higher msg rate, but need to do some more testing.

I also tried the 5/8L active + 4 5/8L radials, didn't work, (too much noise i guess), 5/8L active with 4* 1/4L radials didn't work either, back to 1/4L + 4*1/4L, working nice again. (Also @jepolch, your trick of twisting the wire really helps stiffen it up a touch and straighen it out, before I was rotating it and sliding side of the grip of my wire-cutter along it to straigthen it, having mis-interpreted it, but now I just grabbed one end of the copper wire with pliers, twisted the other end with a power-drill/cordless screwdriver combo and it works like a charm!)

ETA: I've moved the ebay-bought antenna up slightly, number of planes and messages increased noticably, now I'll need to wait and see in the next few days if it is a significant change overal (and not just that it was busier than normal with airplanes when I moved the antenna).

ATM i'm getting the following:
Ebay Antenna: 43Planes 260MSg/sec
1/4L twisted Spider: 31 planes 75Msg/sec
Triangle Spider: 39 planes 220/sec

the ebay antenna is higher than the other two though.

ETA: getting busy, trianglespider picked up 50 planes @ 280msgs/sec just now,
ebay antenna is also around 50 planes on roughly 300 msgs
Click to expand...
Wow, great. I may try one of those triangle spiders. :)
 
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