Announcement

Collapse
No announcement yet.

best antenna

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Dipole Gain & SWR vs Length of it's Limbs
    Theory says SWR=1 when each limb is 1/4 wavelength (68mm)
    Simulation shows SWR=1 when each limb is few mm less than 1/4 wavelength (63mm)!!
    Which one to believe???
    I will have to test this by making a dipole with 68mm each limb.
    Then VRS range plot for 24hrs, trim 2mm, VRS range plot again for 24hrs, trim another 2mm, test again for 24hrs.
    This is driving me crazy.

    dipole vs length.jpg
    Last edited by abcd567; 2015-02-08, 22:55.

    Comment


    • Anyone have any idea at how effective COCO Omnidirectional antenna's are inside the attic/loft? I only have roof tiles, the bare minimum up there so I don't think there would be many things blocking it, I could mount it within the garden however it wouldn't be very high and I'd have to figure a way to route the cable through into indoors.

      Comment


      • Originally posted by MatthewE View Post
        Anyone have any idea at how effective COCO Omnidirectional antenna's are inside the attic/loft? I only have roof tiles, the bare minimum up there so I don't think there would be many things blocking it, I could mount it within the garden however it wouldn't be very high and I'd have to figure a way to route the cable through into indoors.
        MattewE;

        I can only speak for here in Australia but most roofing tiles are made from either cement or terra-cotta and probably wouldn't be good for any antenna signal. That's one reason why one has to get an external antenna above the roof line of your own premises and those around you. Also many homes have the aluminium sisal or the like, let alone all the timber or other construction material which could likely block signal altogether.

        Regards,
        Gregg
        Last edited by fungus; 2015-02-09, 01:17.
        YSSY2/T-YSSY4 [SBS-1 Basestation w/- SSE-1090 SJ Mk2 Antenna (Thanks Delcomp) ] [Uniden UBCD996T w/- 16 element Wideband Discone VHF/UHF Antenna, and tuned 108MHz-137MHz Airband Antenna] [Trialing a home-brew 1090MHz collinear antenna]

        Comment


        • Originally posted by MatthewE View Post
          Anyone have any idea at how effective COCO Omnidirectional antenna's are inside the attic/loft? I only have roof tiles, the bare minimum up there so I don't think there would be many things blocking it, I could mount it within the garden however it wouldn't be very high and I'd have to figure a way to route the cable through into indoors.
          I had hoped to have my homemade coco mounted outside on the roof before winter, but alas, the snow fell early this year and it needs to wait until spring. In the meantime, it's mounted indoors against a second floor indoor balcony. Above is the wooden attic structure with asphalt/ground-stone shingles, and I'm regularly getting 350-400 kms with occasional spikes of greater distances.

          This may not be relevant in your area, however I found that the snow depth on the roof does make a difference to reception especially once it ages and packs itself into ice. Two feet of fresh fluffy snow does not appear to affect the signal significantly, but after it packs down to a few inches of hard snow and ice, reception is reduced by about 75-100 kms until the ice clears.

          The extra indoor time has allowed for some additional tweaks to improve reception.
          These are my January results - red rings are 100kms apart. To the north-east is the thickest buildup of snow-pack on the roof.

          January.jpg
          Last edited by Yxespotter; 2015-02-09, 03:12.

          Comment


          • @MatthewE

            I did all my antenna testing in the loft. I have cement tiles and found I got an extra 20nm once the antenna went outside. When you have something that works well, start thinking about how you would get it outside. Your location will ultimately decide your maximum range and "hits".
            T-EGUB1

            Comment


            • The old saying we have is... :

              The Higher the better...!
              (F-EDLE1)delcomp-DEL-David Tks(My friend Mike, all three of them)

              URL: http://banner.flightdiary.net/EDLM
              1090SJ(Ae) /(6m. Ecoflex10) / SBS 3 /-FR24 Box/ Power-line Connection (Ethernet)

              Comment


              • Originally posted by delcomp View Post
                The old saying we have is... :

                The Higher the better...!
                Absolutely agree mate, .... until things go wrong. The SSE 1090SJ that you gave me has failed (could be the amp- the injector has tested ok as it's here inside the house) and I need to test and check the amp- on the 30' mast atop the ridge capping installed by the professional TV guys. Looks like the cockies, corellas and galahs have been busy 'enjoying' chewing my setup. The 'boss' wont let me climb up on the roof so I'm not too sure how I'm going to proceed from here (don't want another spell in hospital). So for now I'm back on the Discone with limited range. At least it keeps me out of the boss's hair for a while sorting it out.

                Regards,
                ... and there'll be an answer to it somewhere, sometime I'm sure,
                Gregg
                Last edited by fungus; 2015-02-09, 12:05.
                YSSY2/T-YSSY4 [SBS-1 Basestation w/- SSE-1090 SJ Mk2 Antenna (Thanks Delcomp) ] [Uniden UBCD996T w/- 16 element Wideband Discone VHF/UHF Antenna, and tuned 108MHz-137MHz Airband Antenna] [Trialing a home-brew 1090MHz collinear antenna]

                Comment


                • So....getting back to the original post 224 pages ago.

                  What are the top rated 2 or 3 ADS-B antennas right now? I have moved and do not have the space
                  for homebrew so they will need to be store (web) bought.

                  Thanks
                  Ken

                  Comment


                  • Originally posted by CanadaKen View Post
                    So....getting back to the original post 224 pages ago.

                    What are the top rated 2 or 3 ADS-B antennas right now? I have moved and do not have the space
                    for homebrew so they will need to be store (web) bought.

                    Thanks
                    Ken
                    Ken,

                    As I indicated in my last post forget a Discone as it's a broad frequency spectrum antenna not designed specifically fo ADS-B, whereas the SSJ 1090 is and you'd get far more range. As mentioned both on this and other threads it is discontinued but if you search you'll find links to antennas designed for ADS-B which are currently available. The type of receiver you have can also have a bearing on what best suits your situation. There is a thread for best purchased antennas (current) so I'll post the link when I can find it.

                    It's also important to match the amplifier (if used) to the antenna. With my setup I cant use the same amp with the Discone as I can with the SSJ1090 and vice-versa and expect the same results due to the SSJ having a DC bridge whereas the Discone doesn't.

                    http://forum.flightradar24.com/threa...(for-purchase)

                    Regards,
                    Gregg
                    Last edited by fungus; 2015-02-12, 09:09. Reason: added link and additional info
                    YSSY2/T-YSSY4 [SBS-1 Basestation w/- SSE-1090 SJ Mk2 Antenna (Thanks Delcomp) ] [Uniden UBCD996T w/- 16 element Wideband Discone VHF/UHF Antenna, and tuned 108MHz-137MHz Airband Antenna] [Trialing a home-brew 1090MHz collinear antenna]

                    Comment


                    • Thanks for that, I can't believe my own stupidity! I simply hadn't ticked the receiver range options in the map menu!
                      Here is a 72 hour plot.
                      Circles are 90 nm intervals so I'm happy with this - the radio line-of-sight distance to the East for aircraft at 40,000 feet is around 250 nm so I'm not going to improve on this whatever I do. I calculate that to get the same range to the west my antenna would have to go up another 250 feet or so to see over the hills.
                      Many thanks for all your patience and help.
                      Range.jpg

                      Comment


                      • Originally posted by Scroggie View Post
                        ........Here is a 72 hour plot.
                        Circles are 90 nm intervals so I'm happy with this - the radio line-of-sight distance to the East for aircraft at 40,000 feet is around 250 nm so I'm not going to improve on this whatever I do......
                        [ATTACH=CONFIG]5653[/ATTACH]
                        Great, good coverage. Congratulations.
                        Last edited by abcd567; 2015-02-11, 04:13.

                        Comment


                        • Originally posted by Scroggie View Post
                          Thanks for that, I can't believe my own stupidity! I simply hadn't ticked the receiver range options in the map menu!
                          Here is a 72 hour plot.
                          Circles are 90 nm intervals so I'm happy with this - the radio line-of-sight distance to the East for aircraft at 40,000 feet is around 250 nm so I'm not going to improve on this whatever I do. I calculate that to get the same range to the west my antenna would have to go up another 250 feet or so to see over the hills.
                          Many thanks for all your patience and help.
                          [ATTACH=CONFIG]5653[/ATTACH]
                          Good god! Got any pictures of your antenna/mast/array
                          toString - London, UK
                          FR24 - T-EGLC55 / PiAware - toString / PlaneFinder - 9008
                          Raspberry Pi B+ | Keedox DVB-T USB RTL-SDR [RTL2832U+R820T] | Stock Antenna

                          Comment


                          • THE SPLIT CANTENNA - A HYBRID OF CANTENNA & SPIDER

                            New concept, not yet put to trial run.
                            24-hrs trial run & VRS Range plot yet to be done


                            THE SPLIT CANTENNA
                            DSC03535-R.JPG . DSC03537-R.JPG . DSC03539-R.JPG


                            ORIGINAL CANTENNA
                            Cantenna.jpg
                            Last edited by abcd567; 2015-02-14, 21:21.

                            Comment


                            • How about these new 222ml coke cans that have hit the market? ... seems Coke might be phasing out the 355ml cans in favor of them but keeping the price the same

                              http://time.com/money/3667808/mini-c...d-value-price/
                              www.ADS-B.ca

                              Comment


                              • Originally posted by 1090 MHz View Post
                                How about these new 222ml coke cans that have hit the market? ... seems Coke might be phasing out the 355ml cans in favor of them but keeping the price the same

                                http://time.com/money/3667808/mini-c...d-value-price/
                                The 355mL/12 oz can has a diameter 66mm, and performs good as Cantenna. I have also tried 222mL can (55 mm dia) and their performance as Cantenna is somewhat inferior to 66mm dia can.

                                For Split Cantenna, I cannot say anything as I have not tried any. It is just a concept which came to my mind only yesterday and I made it from 66mm dia can. I feel that for Split Cantenna it is likely that 222mL/7.5 oz (55m dia) can may also prove good. However unless these are put to trial run for couple of days and results seen, nothing can be said with surety.

                                355mL-12oz vs 222mL-7.5oz.jpg
                                Last edited by abcd567; 2015-02-15, 01:59.

                                Comment

                                Working...
                                X