Radarspotting

DIY V-STUB ANTENNA MADE OF COAX

DIY V-Stub Antenna made of RG-6 coax. It can be made with any type of coax rated for 1 GHz or higher.

NOTE:
(1) On top, the small sliding piece of wire (with core insulation to hold the sliding wire in place) is for conveniently adjusting the length of top wire for best MESSAGE RATE (if no swr meter is available) or minimum SWR, if SWR meter is available.

(2) Being mechanically weak and prone to ingress of moisture inside the Coax, this antenna is NOT suitable for outdoor installation. It is intended for indoor installation near a window or in a balcony. Please see snapshot-2 below.




SNAPSHOT-1: ANTENNA CLOSEUP
(https://i.postimg.cc/d37xxmqF/V-Stub-top.png)
(https://i.postimg.cc/KjdHSkzM/V-Stub-bottom.png)



SNAPSHOT-2: INDOOR INSTALLATION
(https://i.postimg.cc/3NYcK4Q4/V-Stub-Indoor-800x800.jpg)



Pigtail required to connect RG-6 coax to Radarbox Flightstick or FlightAware Pro Stick
30 / 50 / 60 cm, F-female to SMA-male pigtail RG316 / RG58 / RG174

(https://i.postimg.cc/9QGFkyMy/V-Stub-pigtail-RG316.jpg)

OR

(https://i.postimg.cc/tgpCG7Zw/V-Stub-pigtail-RG174.png)


COMPUTER SIMULATION RESULTS

Diagram 1 of 5: Geometry
(https://i.postimg.cc/dQXXTXBV/V-Stub-Geomery.png)



Diagram 2 of 5: GAIN & Radiation Pattern
(https://i.postimg.cc/VLCh9RGB/V-Stub-Gain-and-Pattern.png)



Diagram 3 of 5: SWR
(https://i.postimg.cc/BnfVmKRW/V-Stub-SWR.png)



Diagram 4 of 5: 3-D Radiation Pattern
(https://i.postimg.cc/3wKbTHKn/V-Stub-3-D-Pattern.png)



Diagram 5 of 5: Current+Phase
(https://i.postimg.cc/KYJpcsjF/V-Stub-Current-Phase.png)

BUILD FOR OUTDOOR INSTALLATION


For a stronger build, suitable for outdoor installation
(1) Use N-connector or SO239 connector.
(2) Use whip and radials made of 2mm or 2.5 mm dia wire. 
Please see photos below.



(https://i.postimg.cc/BQwVY89q/SO239-groundplane-A.jpg)



(https://i.postimg.cc/JhjYzPyn/so239-groundplane-B.jpg)



(https://i.postimg.cc/Qtb6pCJZ/so239-groundplane-C.jpg)


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