BEGINNERS #2: CANTENNA – Easy DIY Antenna to Improve Range/Plane count

Home – Serving the Flight Tracking Enthusiast Forums Feeding and Hardware BEGINNERS #2: CANTENNA – Easy DIY Antenna to Improve Range/Plane count

This topic contains 17 replies, has 10 voices, and was last updated by  newuser25 2 months, 1 week ago.

Viewing 15 posts - 1 through 15 (of 18 total)
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  • #173

    abcd567
    Participant

    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 whip 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 solidly 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 IS AN EASY DIY ANTENNAS FOR BEGINERS:

    EASY ANTENNA # 1 – THE CANTENNA

    Stuff Required:
    (1) MCX to F Pigtail & RG6 Coax shown above.

    (2) Standard Drink Can 330/350 ml (65 mm dia)
    drink can 330ml or 350 ml 65 mm dia

    (3) F-female to F-femalw barrel connector
    F-female to F-female Barrel Connector

    How to Make

    Image 1 of 5: Completed Cantenna

    Cantenna was invented, designed & built by author of this post (abcd567) in June 2014

    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 2 of 5 : Construction Details 1

    Image 3 of 5 : Construction Details 2

    Image 4 of 5 : Construction Details 3

    Image 5 of 5 : Fully Assembled

    DIMENSIONS

    Sketch 1 of 2: Drink Can Dimensions

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

    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 3 Hrs Run
    The range rings are 50 nm apart, the outermost blue ring is 300 nm from the receiver.

    CANTENNA IN AN ENCLOSURE (PLASTIC BOTTLE/JAR) FOR OUTDOOR USE

    Cantennas using other types of cans:

    .

    • This topic was modified 1 year, 8 months ago by  abcd567.
    #175

    Dan
    Keymaster

    That’s a pretty impressive range..

    #176

    abcd567
    Participant

    Hi Dan!
    That was 3 hrs plot. Below is 24 hrs plot.

    VRS Range curve 24 hrs

    #192

    jprochazka
    Participant

    Nice antenna design simple, cheap, fast to make. Just made a 978MHz version tonight.

    UAT Cantenna

    My 1090MHz version was averaging about 175nm and on a good day would steadily reach 250nm.

    #198

    abcd567
    Participant

    jprochazka said:
    Nice antenna design simple, cheap, fast to make. Just made a 978MHz version tonight.

    Thanks jprochazka!
    When I designed Cantenna in June 2014, my objective was to design an antenna which is simple and easy to make by a novice, and above all has large dimensional tolerance so that it can give good predictable results. This was to find a better alternative to DIY Coco, which is very unpredictable and gives varying results from poor to very good for different DIY novice.

    At concept & design stages, I did not expect my invention will prove so good. It was only after making and testing a prototype I realized that it is not only very simple, cheap, fast & easy to make, but also a very good performer.

    At it’s birth in June 2014, I have named it “1/2 λ sleeved dipole”. In August 2014, I renamed it to the simple & easy name “Cantenna”, originating from:
    Cantenna = Can Antenna
    Cantenna = Canadian Antenna

    Regards,
    ab cd

    .

    #199

    frazpo
    Participant

    Yes I have used this design and it works really well. Must be derived from the 2m concept?
    http://www.amateurradio.bz/coffee_can_antenna.html

    I was amazed at the performance. If your simply using the stock antenna and are not interested in anything external then this would be a great option.

    #200

    abcd567
    Participant

    frazpo said:
    Yes I have used this design and it works really well. Must be derived from the 2m concept?
    http://www.amateurradio.bz/coffee_can_antenna.html

    Thanks for pointing out.

    There are three possibilities:
    (1) I derived from him
    (2) He derived from me
    (3) Both of us derived independently.

    Possibility (1) is ruled out as I was not aware of the Coffe Can antenna of Dave Tadlock when I designed the Cantenna. In fact I was inspired by an old timer “Coaxial Antenna” (see diagram below) which used a copper tube/pipe sleeve which was slightly bigger in dia than the the coax. This antenna was not popular, and was used mainly in rubber-ducky antennas of Hand-held radios. The main reason for its drawbacks seemed to be the narrow gap between sleeve and coax. I thought of using a larger dia sleeve to overcome the drawbacks of the “Coaxial Antenna” and decided to use a drink can to act as large dia sleeve. This gave birth to the wide-bodied derivative of “Coaxial Antenna”, which I originally named “1/2 λ sleeved dipole” and then renamed “Cantenna”.

    Possibility (2) is ruled out as the date of Dave Tadlock’s Youtube video is Oct 2012, before the date of my design which is June 2014.

    This leave possibility (3) … We both designed it independent of each other. I would like to give credit to Dave Tadlock for conceiving the concept of using a can as sleeve 2 years before I conceived it independently and unaware of Dave Tadlock’s design.

    However I have note that Dave Tadlocks design ignored the fact that for the antenna to be optimal, the whip height AND can height both should be equal (see diagram below). In his design, the coffee can height is much smaller than whip height. This makes the can act mostly as a ground-plane and only a partial sleeve

    The Old Timer “Coaxial Antenna”

    #201

    frazpo
    Participant

    Its a good economical antenna. Thats what matters 🙂
    I saw a local hams FB page utilizing the “can” plan and made the connection. I had wondered where he got the idea from and found that some time ago.

    #203

    abcd567
    Participant

    frazpo said:
    Its a good economical antenna. Thats what matters…

    Yes, this was my objective when I set to design Cantenna. Additional objectives were:

    (1) The antenna should not require high accuracy and high dimensional tolerance, so as to suite the “DIY by a Novice” situation.

    (2) The materials used should be low cost and readily available world wide. No special connectors like SO239 and PL 259 were used which require to be specially ordered in most countries of the world.

    #204

    abcd567
    Participant

    Comparison of “coaxial antenna”, “2m coffe can antenna” and “cantenna”

    OPTIMIZATION CRITERIAS

    CRITERIA 1: THE WHIP & SLEEVE SHOULD BE SAME LENGTH TO PROVIDE A BALANCED ANTENNA WITH PROPER RADIATION PATTERN
    coaxial antenna = yes
    cantenna = yes
    2m coffee can antenna = no

    CRITERIA 2: THE SLEEVE SHOULD BE 1/4 λ TO PROVIDE DECOUPLING OF FEEDER COAX
    coaxial antenna = yes
    cantenna = yes
    2m coffee can antenna = no

    CRITERIA 3: THE SLEEVE DIAMETER SHOULD BE MUCH LARGER THAN DIAMETER OF COAX TO INCREASE AIR GAP AND REDUCE LOSSES.
    coaxial antenna = no
    cantenna = yes
    2m coffee can antenna yes

    CRITERIA 4: THE WHIP SHOULD BE 1/4 λ TO MAKE ANTENNA IMPEDANCE CLOSE TO 75 OHMS, MATCHING WITH RG6 COAX AND DVB-T IMPEDANCES WHICH ARE 75 OHMS.
    coaxial antenna = yes
    cantenna = yes
    2m coffee can antenna = no

    From above comparison, it is clear that it is only cantenna which meets all the optimization criteria. 🙂

    #212

    abcd567
    Participant

    I have just now worked out a design of 1090 MHz antenna based on “2 meter Coffee Can Antenna” design as follows:

    2m coffee can antenna dimensions
    (1) Wavelength λ = 2 meters = 2000 mm

    (2) Whip height = 25-1/4 inches = 641 mm
    when expressed as fraction of wavelength, whip height = (641/2000) λ = 0.32 λ

    (3) Coffee can height = 6-1/4 inches = 159 mm
    when expressed as fraction of wavelength, coffee can height = (159/2000) λ = 0.08 λ

    Translating the design to 1090 MHz

    (1) Wavelength at 1090 MHz = λ = 275 mm

    (2) Whip height = 0.32 λ = 0.32 x 275 = 88 mm

    (3) Pepsi can height = 0.08 λ = 0.08 x 275 = 22 mm

    I am considering to make one with above dimensions, put on trial run and compare results with cantenna.

    #422

    frazpo
    Participant

    When utilizing a filter and an amp in which order do they go in the setup from the dongle to the antenna??

    A fellow feeder in Ks tried an amp but thinks he just amplified a bunch of noisy cell site noise.
    He is adding the 1090 FA filter. Need to know if it before or after the amplifier.

    #614

    oh2eko
    Participant

    While i do know about antennas my question is how did you generate that plot?
    I seem to be unable to find anything like it in virtual radar server

    #615

    Edwin van den berg
    Participant

    @frazpo
    When utilizing a filter and an amp in which order do they go in the setup from the dongle to the antenna??

    A fellow feeder in Ks tried an amp but thinks he just amplified a bunch of noisy cell site noise.
    He is adding the 1090 FA filter. Need to know if it before or after the amplifier.

    The filter must be after the amp.
    so between the amp and the reciever.

    Edwin

    #2007

    avsa242
    Participant

    abcd567,

    Just wanted to say this works fantastically. I live in a first-floor apartment on a hill, in a bit of a valley, so my options for an antenna, or at least placement of one, are very limited. I have a broadband Antennacraft antenna that I use for general-purpose listening that works quite well, but doesn’t really excel at receiving any particular band. 1090 is O-K, but nothing spectacular, 40nmi out at best. I’ve tried making this and a collinear antenna out of RG6. The latter doesn’t seem to work any better than the Antennacraft (could be workmanship, could be something else – not sure). The cantenna, however, sees past 80mi with a decently wide coverage. It was a great deal easier to build, as well.

    Cheers!
    Jesse

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