Three Easy DIY Antennas for Beginners

NOTE: Those who dont want to make a DIY antenna, can order Flightaware’s antenna from Amazon
http://www.amazon.com/gp/product/B00WZL6WPO

STARTER
When DVB-T Dongle is purchased, a whip antenna is supplied with it. Every beginner uses this whip in his starter setup.
Improve the performance of this whip antenna by three simple steps given below:
(1) Whip is too long for 1090 MHz. Cut it to 67mm.
(2) Magnetic base provides an insufficient ground-plane. Enlarge ground-plane by placing the whip over a Metallic Can/Box/Plate. An added advantage of placing whip over an iron/steel can is that whip’s magnetic base will cling to the can and keep the whip stable & upright.
(3) Signal is weak indoors. Place whip near a window or in attic to get maximum signal.


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NEXT STEP
Once your setup is up and running, you will be happy, but soon after you will want to increase your range. You can then try some easy and sure antenna, like Spider & Cantena. In next two posts below, there are “how to make” instructions for Spider & Cantenna.

VENTURING BEYOND…
Next step may be to venture through alluring coaxial antennas (coaxial cillinear, popularly known as coco, franklin, wire collinear with coils). These antennas are very alluring, as these are easy to make, and all postings on internet & youtube claim high gain excellent antenna. The problem shows up when these antennas are put to service, and give poor perfamance. Collinears are very hard to get right, and except for few lucky ones, most DIY collinear makers end up with a poor performing antenna.
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**3 EASY ANTENNAS FOR BEGINNERS
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The main disadvantages of stock antenna supplied with DVB-T USB Dongle are:
Problem (1): It has a very short lead. Due to this, in most cases the antenna cannot be placed at an optimum location.
Problem (2): The stock antenna is not optimized for 1090 Mhz.

SOLUTION FOR PROBLEM (1):
The short cable length can be overcome by connecting a MCX to F pigtail to the DVB-T USB Dongle, and connecting to the pigtail, the required length of commonly available RG6 cable with a DIY antenna at other end of RG6 cable.


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

SOLUTION FOR PROBLEM (2):
The non optimized antenna can be replaced by a DIY antenna which has a ¼ wavelength vertical whip connected to core of coax cable, and a ground plane connected to shield of coax. The ground plane can be formed by a disc, a number of horizontal radials, a number of slanting radials, or a food/drink can.

Below are 3 different easy antennas for beginners: Spider, Platenna, & Cantenna.
These all have a ¼ wavelength vertical whip connected to core of Coax cable, but use different methods of providing ground plane connected to shield of coax.

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EASY ANTENNA # 1 : SPIDER

Parts Required:

  1. SO-239 Connector
    https://farm8.staticflickr.com/7606/16757306295_5a20bc2d3b_q.jpg

  2. PL-259 UHF to F adapter (to connect RG6 coax to SO-239 Connector)
    https://farm9.staticflickr.com/8742/16574698267_baea252207_q.jpg

  3. Copper wire pieces 10 cm long - 5 pieces for 4 Leg Spider, 9 pieces for 8 Leg Spider.

  4. Small Nuts & bolts 4 pieces for fixing wires at 4 corners of SO239 adapter

Schematic & Dimensions

Finished Antenna 4 Legs (Does not require soldering)
Built by jepolch
http://forum.planefinder.net/threads/ads-b-diy-antenna.23/page-31

Finished Antenna 4 Legs (Does not require soldering)
Built by beckerm13 http://discussions.flightaware.com/post153170.html#p153170

Finished Antenna 8 Legs (Requires Soldering - Performs better than 4 Legs)
Built by autok
http://www.atouk.com/wordpress/?page_id=237

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EASY ANTENNA #2 : CANTENNA

Please see below photos, showing construction details.

**Completed Cantenna

Designed & Built by Author of this post (abcd567)**


The whip at top is ¼ wavelength i.e. 69mm (see dimension drawing below)
The whip is core wire of coax cable.
It can be bare copper wire OR copper wire + core insulation.
Shield (braid+foil) MUST be removed from the whip.

Image 1 of 4 : Construction Details 1

Image 2 of 4 : Construction Details 2

Image 3 of 4 : Construction Details 3

Image 4 of 4 : Fully Assembled

DIMENSIONS
Sketch 1 of 2: Pepsi Can Dimensions

Sketch 2 of 2: Whip Measurements.
Any one of the two connectors shown in the sketch below can be used


Details of whip, if insulated whip is used. The whip can also be un insulated bare copper wire like core wire of coax

Test Setup for CANTENNA

Picture 1 of 2

Image 2 of 2 : VRS Coverage
The range rings are 50 nm apart, the outermost blue ring is 300 nm from the receiver.

Cantennas using other types of cans:

Built by giacomo1989 http://forum.planefinder.net/threads/ads-b-diy-antenna.23/page-25#post-1530


Built by jepolch http://forum.planefinder.net/threads/ads-b-diy-antenna.23/page-74#post-2607

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EASY ANTENNA # 3 : PLATENNA
POST DELETED. NOT AS GOOD AS CANTENNA AND SPIDER

Lots of people talk about building CoCo (Collinear antennas made from co-axial cable) - yes they are cheap to make, but it is also very easy to make a bad coco that doesn’t work well.

Essentially ADS-B is line of sight, the maximum range is to the horizon, and one of the simple antennas above will get you most of the way there.

You can check your antenna performance by going to web site heywhatsthat.com/ do a new panorama Mark your exact antenna location and enter it’s height above the ground. The backend will calculate your horizon taking into account earth curvature, mountains, hils etc. On the map that is produced select ‘In the Air’ then zoom out 'till the map is probably 1000km wide (closer you won’t see the range rings since they’ll be outside the map segment you’re viewing). now in the bottom of the map say you want an outer ring at 40,000 feet … that will be about as far as you will see. If the horizon is over the ocean you seem to get a better range ???

How what is that will not take into account the shading of the signals that is caused by surrounding buildings, bags of water (also called trees), placing the antenna under something that cuts down the signal (like roof tiles or a long downlead), etc.

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With the antennas above, if putting them outside - seal the base of the top spike with a blob of silicon caulk.

consider spraying the assembly with a spray lacquer to prevent corrosion.

Nice Antennas.

This is my construction http://blog.wenzlaff.de/?p=4668 (in german).

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DIY QUICK SPIDER - No Soldering Required, No SO239 Connector Required

Maximum Range Curve By VRS
HARDWARE: Quick Spider >> 12 ft / 4 m RG6 Coax >> Generic DVB-T (black) >> Orange Pi PC


Trial Run - Indoor Near Large Window

HOW TO MAKE

Please see these posts also for previous Versions:
(1) May 2015
(2) September 2016

STEP 1 - Stuff Required

STEP 2 - Cut Coax Into Required Pieces

STEP 3 - Remove braid & Insulation

STEP 4 - Bend Wires

STEP 5 - Assemble Radials

STEP 6 - Bend Down Radials 45 Degrees


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STEP 7 - ENHANCEMENT FOR OUTDOOR USE

  1. Apply a rapid setting (5 minutes) sealant like 2-part epoxy, or silicone, or hot melt glue, or similar at the point where radials enter the outer jacket of coax.

  2. After installation. wrap the F-connector in tape to prevent moisture ingress. You may also use outdoor type F connector which are water resistant

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holy capslock batman.

maybe it’s time we had a sub-forum on how to build antennas?

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For the panel mount connector Spider antennas, use an N connector if you have a choice. I’m a single data point, but I’ve made several with N and UHF (SO-239) and the N connector versions provide more position tracks. YMMV, but it stands to reason since UHF connectors are only intended for <300MHz.

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EASY SIX LEG GROUNDPLANE / SPIDER ANTENNA
**USES ONLY ONE F-TYPE COAX CONNECTOR (With Nut & Washer)


No soldering required.
No special connectors (like SO-239, BNC or N connectors) required.

FINISHED LENGTHS
WHIP: From top of F-connector to top of whip = 69 mm

RADIALS: From Point of bending down to tip of radial = 69 mm

RADIALS BENDING DOWN: About 45 degrees below horizontal

WIRE DIA: Flexible. In this demo core wire of RG6 coax cable is used which has a dia of 1 mm (18 AWG), but wires with bigger dia can as well be used.

STEP-1

STEP-2

STEP-3

ON TRIAL RUN

DIRECTLY BUILT ON AN AMPLIFIER, INSTEAD OF F-CONNECTOR**

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SIMULATION OF 2 DIY ANTENNAS

Simulation 1 of 2: SPIDER (8 Legged )
Gain = 1.7 dBi
SWR (75 ohms) = 1.3


Simulation 2 of 2: CANTENNA
**Gain = 1.9 dBi
SWR (75 ohms) = 1.5
**


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Can this me made a sticky, so it stays near the top for the newcomers to find easily?
…Tom

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Done. Can you also link to FA’s antenna? amazon.com/gp/product/B00WZL6WPO

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Thanks.
Link to FA’s antenna added. Please see first post of this thread, below the heading.

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Thank you.

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Good DIY choice - Franklin antenna. Solid copper wire 3 or 4mm about 1m long without insulation needed.
http://adsbradar.ru/sites/default/files/i/franklin_0.JPG
Half-wave vibrators (pieces of 133mm (5.24inch)) should be strictly in one line.
http://adsbradar.ru/sites/default/files/i/franklin3.png
The estimated gain of 3.2db. This antenna works on my radar http://alexhash.noip.me:8080
http://adsbradar.ru/antenna-franklin-1090mhz

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For those of you nervous to cut a soda can or don’t have the tools I have found that a Bush’s 8.3oz baked beans can is just over 70mm long.
The can has a pull off lid and so therefore saves you cutting the can.
All you have to do is drill a hole in the center of the closed end to mount the antenna.

Made one of these tonight and will let it run a few days.

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In my Cantenna, I use an insulated whip (core wire of RG6 coax with core’s insulation). The length of whip was 69 mm. Few days ago I cut 3 mm off the top of whip, making it 66 mm long. I noticed not very big, but noticeable improvement in performance.

With bare copper wire whip, a lesser chop-off may be required, say 1 or 2 mm instead of 3 mm (making whip 68 or 67 mm long). I have yet to try the chopped-off bare wire whip.

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Scissors will usually do a light aluminium drinks can - just punch the narrower blade through lower than you need an spiral up.

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