ADS-B DIY Antenna

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jepolch

Active Member
the 90* ones? I use the other end of the pivot point on my wire cutters, the gap in between the handles is ever so slightly smaller than the copper wire radius, so I can use it as a kind of miniature vice/vise (the big heavy things you can clamp stuff in). and just bend it by hand in one fluid go, afterwards I applysome pressure on both sides of the bend (if there is enough space) to make them even more straight/square. Ill post some pics/sketches tomorrow, for now its time to sleep ;)
Good idea. When I made my Franklin I did all the bends in the vise. Looking forward to hearing how that one works out. :)
 

ab cd

Senior Member
I'll try and make the radial, and see how it works on my trianglespider!

ETA:
I'm also thinking of trying slightly different triangle radials, currently I have them folded in triangle shape, but the end is insulated from the rest, I.E. it should work as a 3/4L radial. Im planning on making a second set of triangle radials where the end IS connected to the start to make a kind of butterfly-like connected 1/4L dipole with a slightly larger BW.

Once more, new antenna build, swapping it right now :D
View attachment 1574

ETA2: first results with the triangle radials are a bit crappy, so switching to 1/4L 45* radials right now.
Your rightangle wire bends and straightness of wire are amazing. You are very crafty!

What is the total length of wire in the phasing stubs?

Important: Total length of wire in phasing stub = ½ wavelength = 138 mm.
(1) Straight stub = 66mm+6mm+66mm=138mm
(2) Zigzag stub = 32mm+5mm+64mm+5mm+32mm=138mm

Stub gap (center-to-center distance between horizontal wires of stub) is NOT critical. Can be 6mm +/- few mm, but then length of horizontal portions to be adjusted to make total length of wire in stub = 138 mm (½ wavelength).
 

giacomo1989

Member
I'll try and make the radial, and see how it works on my trianglespider!

ETA:
I'm also thinking of trying slightly different triangle radials, currently I have them folded in triangle shape, but the end is insulated from the rest, I.E. it should work as a 3/4L radial. Im planning on making a second set of triangle radials where the end IS connected to the start to make a kind of butterfly-like connected 1/4L dipole with a slightly larger BW.

Once more, new antenna build, swapping it right now :D
View attachment 1574

ETA2: first results with the triangle radials are a bit crappy, so switching to 1/4L 45* radials right now.

That copper looks great. How can you handle it so precisely?
 

jepolch

Active Member
Wow jepolch! I never new you are so good in craft. Great!
Thanks! I haven't made any models out of paper (card stock) in a while. My hands aren't as steady as they used to be. But I have one printed out that I'm going to try and see how well I can do.
 

ab cd

Senior Member
Thanks! I haven't made any models out of paper (card stock) in a while. My hands aren't as steady as they used to be. But I have one printed out that I'm going to try and see how well I can do.
Typo: my mistake - "new" instead of "knew"
 
Wow jepolch! I never knew you are so good in crafting things. Great!

Agreed, Amazing skills jepolch !
I have a question though from your great photo set.
Is that a cosmonaut hamster tucked up inside the capsule ?
I am sure I can see his eye squashed up against the plexiglass in one of the outdoor shots on the pad.
Perhaps he was just getting a feel for his ship before the big day. Just livin the dream !
Hes got the right stuff for sure ! :)
 
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jepolch

Active Member
Agreed, Amazing skills jepolch !
I have a question though from your great photo set.
Is that a cosmonaut hamster tucked up inside the capsule ?
I am sure I can see his eye squashed up against the plexiglass in one of the outdoor shots on the pad.
Perhaps he was just getting a feel for his ship before the big day. Just livin the dream !
Hes got the right stuff for sure ! :)
Dang! That was my secret! I didn't think anyone would find out. I should have known someone in this forum would outsmart me! :eek:
 

xforce30164

Active Member
Your rightangle wire bends and straightness of wire are amazing. You are very crafty!

What is the total length of wire in the phasing stubs?

Important: Total length of wire in phasing stub = ½ wavelength = 138 mm.
(1) Straight stub = 66mm+6mm+66mm=138mm
(2) Zigzag stub = 32mm+5mm+64mm+5mm+32mm=138mm

Stub gap (center-to-center distance between horizontal wires of stub) is NOT critical. Can be 6mm +/- few mm, but then length of horizontal portions to be adjusted to make total length of wire in stub = 138 mm (½ wavelength).

Thanks! I try to be precise :D.
IMG_20150408_101222.jpg



That copper looks great. How can you handle it so precisely?
Here's what I use most of the time to bend it:
IMG_20150408_101153.jpg

IMG_20150408_101202.jpg


You can also see what I meant with how I use the "other side" of my wire-cutter tool to bend the wires, (wire not bended here though but you get the idea ;) )

ETA: I Might have a second go at the smaller prototype with franklin stub (the more Z-like stub) as it seems a tad too long, the other frankenspider seems to perform better than the new one. (which has 140mm of wire in the matching section, so that is a lot closer to the 138mm)
 
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The craftsmanship is amazing both on the paper models jp, and the wire bending xforce.
I see the written work has improved significantly since the mention of 200 lines !
 

borchi

New Member
Hallo,

after reading this very cool thread i build a cantenna and connected it to my Raspberry Pi / DVB-T stick combo.
It works fine on my first try, placed inside, no amplyfier. At the moment traffic is very low here, but i got a max range of about 110 nm.
 

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ab cd

Senior Member
Hallo,

after reading this very cool thread i build a cantenna and connected it to my Raspberry Pi / DVB-T stick combo.
It works fine on my first try, placed inside, no amplyfier. At the moment traffic is very low here, but i got a max range of about 110 nm.
Willkommen an bord!
Antenne mit schönen Blumen!


Welcome aboard!
Antenna with nice flowers!

When you move your antenna outside (or better on roof), your range will greatly improve in all directions.

Adding an amplifier will increase the range by another 50 to 100 nm.
 
Hallo,

after reading this very cool thread i build a cantenna and connected it to my Raspberry Pi / DVB-T stick combo.
It works fine on my first try, placed inside, no amplyfier. At the moment traffic is very low here, but i got a max range of about 110 nm.

Hallo Borchi,
Welcome to you
Very nice antenna holder, I like this !;)

Perhaps you would get more planes by taking the small conversion lead away from your system,
you would need this component to do this

http://www.ebay.co.uk/itm/161102747637?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Sie könnte vielleicht bekommen mehr Flüge , wenn Sie diese component.This direkte Verbindung mit dvb- t machen.
Das kurze Kabel schlechter Qualität manchmal. Kleine Veränderungen können große Verbesserungen , um den Empfang von Flügen zu machen.



A spider antenna umbrella would look very good with your candle lady antenna stand :)
 

ab cd

Senior Member
@radiostationx:
@borchi:
In my opinion, the F to mcx adapter cable used by borchi is better option than a solid F to mcx adaptor because:
1) The RG6 coax is stiffer & heavier than the thin flexible adapter cable pigtail now used by borchi. Using solid adapter will result in undue mechanical force of heavy RG6 coax transferred to the female mcx socket of DVB-dongle, and damage it in due course. The thin flexible pigtail acts as buffer for mechanical forces.


2) The length of thin flexible coax of borchi's adapter pigtail is so short that any losses introduced by it will be negligible.


F to mcx pigtail.jpg
.
F to mcx adaptor.jpg
 
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ab cd

Senior Member
Thanks! I try to be precise :D.
IMG_20150408_101222.jpg




Here's what I use most of the time to bend it:
IMG_20150408_101153.jpg

IMG_20150408_101202.jpg


You can also see what I meant with how I use the "other side" of my wire-cutter tool to bend the wires, (wire not bended here though but you get the idea ;) )

ETA: I Might have a second go at the smaller prototype with franklin stub (the more Z-like stub) as it seems a tad too long, the other frankenspider seems to perform better than the new one. (which has 140mm of wire in the matching section, so that is a lot closer to the 138mm)
An easier way to get accuracy is to measure & mark on wire the points of bends while the whole wire is still straight, BEFORE starting any bending & cutting.

For example, for straight stub franko-spider, marking can be done on straight wire as follows:

STEP 1:
Point A - top of wire
Point B - 138mm from A
Point C - 66mm from B
Point D - 6mm from C
Point E - 66mm from D
Point F -69mm from E
Point G - 10mm from F (surplus)

STEP 2:
Make 90* bends at already marked points B, C, D, & E.

STEP 3:
Trim length at bottom according to SO239 to make finished height of lower-most section = 69mm.
 
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