Page 1 of 13 12311 ... LastLast
Results 1 to 10 of 130

Thread: 3 EASY ANTENNAS FOR BEGINNERS

  1. #1
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,750

    3 EASY ANTENNAS FOR BEGINNERS

    3 EASY ANTTENNAS FOR BEGINNERS

    The main disadvantages of stock antenna supplied with DVB-T USB Dongle are:

    (1) It has a very short lead. Due to this, in most cases the antenna cannot be placed at an optimum location.
    (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:
    (1) For RG6 coax lengths in excess of 5m/15ft, coax attenuation will be high, and an amplifier may become necessary.
    (2) 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
    Last edited by abcd567; 2015-12-02 at 04:10.

  2. #2
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,750
    EASY ANTENNA # 1 : SPIDER

    Parts Required:

    1. SO-239 Connector
    SO239 standard.jpg

    2. PL-259 UHF to F adapter (to connect RG6 coax to SO-239 Connector)
    PL259 - F to UHF adapter 2.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
    Spider Antenna SO239.PNG


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

    jepolch 4 legged spider.jpg


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

    atouk 8 legged spider.jpg
    Last edited by abcd567; 2015-03-10 at 05:55.

  3. #3
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,750
    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.




    Coverage
    The range rings are 50 nm apart, the maximum distance achieved is 250 nm from the receiver.



    HOW TO MAKE

    Image 1 of 6 : Construction Details 1



    Image 2 of 6 : Construction Details 2



    Image 3 of 6 : Construction Details 3


    Image 4 of 6 : Fully Assembled



    Image 5 of 6 : Details of whip, if insulated whip is used.
    The whip can also be un insulated bare copper wire like core wire of coax





    Image 6 of 6: Sketch of Pepsi Can Dimensions



    Cantennas using other types of cans:


    Built by giacomo1989 http://forum.planefinder.net/threads...e-25#post-1530


    Built by jepolch http://forum.planefinder.net/threads...e-74#post-2607


    .
    Last edited by abcd567; 2015-08-28 at 13:47.

  4. #4
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,750
    EASY ANTENNA # 3 : QUICK SPIDER
    No Soldering Required, No SO239 Connector Required


    Maximum Range Curve By VRS (VirtualRadarServer.co.uk)

    Hardware Used for Range Curve Plotting:
    Quick Spider >>
    12 ft / 4 m RG6 Coax >>
    Generic DVB-T (Black, RTL2832U+R820T) >>
    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


    .


    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


    Last edited by abcd567; 2017-05-03 at 16:25.

  5. #5
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,750
    EASY ANTENNA #4 :
    SIX LEG GROUNDPLANE/SPIDER ANTENNA

    USES ONLY F-TYPE CONNECTOR (With Nut & Washer)



    NO SOLDERING REQUIRED
    NO SO-239, BNC or N CONNECTOR 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

    Last edited by abcd567; 2015-06-17 at 15:40.

  6. #6
    Passenger VOTV's Avatar
    Join Date
    Oct 2014
    Location
    VOTV/TRV, INDIA
    Posts
    3
    Hi,
    Do you think these antennae are better than the FR24 provided regular antenna?
    I host a F-xxxx device and hence curious to know if these DIY antennae can help extending the coverage area?

    cheers
    VOTV/TRV

  7. #7
    Purser
    Join Date
    Mar 2015
    Location
    Mojave Desert, USA
    Posts
    133
    Do you think these antennae are better than the FR24 provided regular antenna?
    Basically, no. I regularly get 320+ NM with the stock FR24 equipment.

    That being said, I like this thread. I have an Airspy SDR and going to mess around with these antenna designs.
    F-KDAG1

  8. #8
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,750
    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



  9. #9
    Passenger
    Join Date
    Aug 2012
    Location
    Maryland, USA
    Posts
    1
    which software are you using to capture the polar diagram? I'd like to run some tests but have no other quantitative way to make measurements.
    Thank you

  10. #10
    Flight attendant
    Join Date
    Nov 2013
    Posts
    61
    Quote Originally Posted by lockon View Post
    which software are you using to capture the polar diagram? I'd like to run some tests but have no other quantitative way to make measurements.
    Thank you
    That looks like the one built in to Virtual Radar Server, SBSPlotter is another one will run stand alone and create .out plots that you can load into basestation etc.

    Jerry

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •