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  • Originally posted by stanno View Post
    I have used the FR24 antenna with the dongle and it doesn't receive the same number of decoded messages. I get a similar range with either the FR24 antenna or my cantenna using the dongle. The antennas are the same height.

    When I put the cantenna on the FR24 receiver i also get a similar range to the dongle - just a lot more decoded messages.

    Obviously the FR24 receiver and the FR24 antenna are closely matched and achieve pretty close to optimal perfomance.
    Thanks for that, looking "whats in the box" for the FR24 gear, it says the antenna is 0dB gain, which might explain why they use a pre-amp as part of the receiver/decoder circuit.. I am still going to tune my antenna as best I can and see how much it improves the performance.

    Another question for the masses... What height above sea level are you at and how far off the ground do you have your antenna? My antenna is only about 5mtrs off the ground part way up a 6ft mast on stop of a single storey house which doesn't help my reception much :/
    T-YBBN50 - Kallangur, QLD, Australia

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    • I am about 3000 ft above sea level and the antennas are about a metre above the roof ridge on a two story house. Unfortunately there are a number of nearby trees that block some of the signals. I do get the occasional contact over 300 nm (460 km) out to sea, but only about 160 nm (300 km) inland. I am about 40 nm (75 km) from the coast.

      The cantenna / dongle / RasPi combination gets occasional peaks at 370 km out to sea and about 280 km inland. There are a lot more holes at lower levels and a lot fewer messages are decoded.

      Comment


      • Originally posted by stanno View Post
        I am about 3000 ft above sea level and the antennas are about a metre above the roof ridge on a two story house. Unfortunately there are a number of nearby trees that block some of the signals. I do get the occasional contact over 300 nm (460 km) out to sea, but only about 160 nm (300 km) inland. I am about 40 nm (75 km) from the coast.

        The cantenna / dongle / RasPi combination gets occasional peaks at 370 km out to sea and about 280 km inland. There are a lot more holes at lower levels and a lot fewer messages are decoded.
        Can you please define "cantenna" for me? I only know cantennas as directional like a DIY gridpack or yagi antenna... As for your height, that's a >.< tiny bit higher than me I am some 106ft above sea level with the mast only a few meters higher Though considering the fact I have 2 storey houses on 2 sides I don't think I do tooo badly...
        T-YBBN50 - Kallangur, QLD, Australia

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        • My cantenna is an upside down 425g tuna can with a BNC coax connector in the middle of the base and a 69mm piece of copper wire mounted vertically from the centre of the connector. The can is 70mm deep which is almost exactly a quarter wave length, and is about 100mm in diameter.
          Attached Files

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          • Originally posted by stanno View Post
            My cantenna is an upside down 425g tuna can with a BNC coax connector in the middle of the base and a 69mm piece of copper wire mounted vertically from the centre of the connector. The can is 70mm deep which is almost exactly a quarter wave length, and is about 100mm in diameter.
            Hope you emptied out the tuna first and gave the can a real good wash. That stuff attracts cats like you wouldn't believe.

            Great job by the way. Amazing what 'can' be done with simple stuff from around the home (not the cats). Also, thanks to you and a couple of others, I can now retire my radar (when I feel the desire to do so) as it gets trounced by all you guys. They don't make (or allow) 400' masts here in Sydney so no point in trying to get the antenna higher.

            Regards,
            Gregg
            Last edited by fungus; 2015-01-27, 11:13.
            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


            • I'm located on the old flood plain (almost returned as one back in 2012), so ground level is about 184m ASL and the antenna is about 196m ASL. I do have some hills near by; Willans Hill (294m ASL), Rocky Hill (255m ASL), Mount Moorong (296m ASL), unnamed hill (250m ASL) at Eunanoreenya and an unnamed hill peaks at Charles Sturt University (290m ASL), part of the rise in elevation to the north/northwest.

              Further a field.
              Lighthouse Hill on the Marlebo Range to the NW of Wagga is 380m ASL, Plum Pudding Hill to the S is about 490m ASL, Mount Flakney to the S/SE is about 533m ASL, Wheel of Fortune (hill is unnamed but the trig and mast site is named that) to the E/NE is about 490m ASL
              F-YSWG1 and T-YSWG2

              Comment


              • Originally posted by bhaal View Post
                Hmmm, my dongle which I got from Adafruit has a 50 ohm input, so for me that wouldn't be an issue... (I have a 30cm pigtail of the original 50ohm coax from the little internal magnetic antenna so that its not 75ohm being shunted straight into the dongle)...
                Ahh cool, 99% of them out there are 75, though the later bit seems a tad strange unless its lengthed out to convert

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                • Yes, I've had numerous issues with LAN flights giving incorrect data - VRS was reporting the flight as being 8000 km away. Hopefully, it'll get fixed soon.

                  As for elevation, my antenna is about 73 metres ASL. What's blocking my view to the east is a whole heap of high-rise buildings, unfortunately.

                  Here's a picture of my simple dipole antenna made from RG-6 cable. I think it gets pretty good range (up to 400 km in some directions), given its simplicity:
                  dipole.jpg

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                  • Anyone know where I can get metal free fibreglass tubing in Brisbane? For a coco? Being that PVC blocks RF etc..... I'm having trouble finding stuff on google..
                    T-YBBN50 - Kallangur, QLD, Australia

                    Comment


                    • Originally posted by eastons View Post
                      Yes, I've had numerous issues with LAN flights giving incorrect data - VRS was reporting the flight as being 8000 km away. Hopefully, it'll get fixed soon.

                      As for elevation, my antenna is about 73 metres ASL. What's blocking my view to the east is a whole heap of high-rise buildings, unfortunately.

                      Here's a picture of my simple dipole antenna made from RG-6 cable. I think it gets pretty good range (up to 400 km in some directions), given its simplicity:
                      [ATTACH=CONFIG]5560[/ATTACH]
                      I'm going to try a dipole soon, as well as a spider antenna or whatever you want to call them..
                      T-YBBN50 - Kallangur, QLD, Australia

                      Comment


                      • Originally posted by eastons View Post
                        Yes, I've had numerous issues with LAN flights giving incorrect data - VRS was reporting the flight as being 8000 km away. Hopefully, it'll get fixed soon.

                        As for elevation, my antenna is about 73 metres ASL. What's blocking my view to the east is a whole heap of high-rise buildings, unfortunately.

                        Here's a picture of my simple dipole antenna made from RG-6 cable. I think it gets pretty good range (up to 400 km in some directions), given its simplicity:
                        Easton,

                        It may be the angle of the photo and/or I may be wrong but is your antenna too close to and the top blocked by the TV antenna at all? Just a simple observation from the pic in your post. One way or other, the LAN issue should be resolved when they either drop the route or get their 787's onto it (I cant remember exactly which I'd read some time back).

                        Regards,
                        Gregg
                        Last edited by fungus; 2015-01-28, 20:51.
                        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 fungus View Post
                          One way or other, the LAN issue should be resolved when they either drop the route or get their 787's onto it (I cant remember exactly which I'd read some time back).
                          It's a bit off topic but anyway. LAN are going to introduce either B787 or A350 on this route in place of the A340. Dunno about you but I wouldn't like to be in a twin for up to 6.5 hours flying on one fan with not many places to put it down - the far south Pacific is not the North Pacific. The B787-9 is apparently ETOPS rated for this duration. I understand the statistical probability behind ETOPS ratings but still firmly believe that a quad offers a greater margin of safety on routes like this one.

                          Comment


                          • Originally posted by bhaal View Post
                            Anyone know where I can get metal free fibreglass tubing in Brisbane? For a coco? Being that PVC blocks RF etc..... I'm having trouble finding stuff on google..
                            HUH?

                            Only the deep grey type blocks RF, the off white, white, light grey, don't, I think orange doesnt either - but that would look ridiculous. Bunnings or Masters should be able to help you.

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                            • It may be the angle of the photo and/or I may be wrong but is your antenna too close to and the top blocked by the TV antenna at all?
                              Yes, it's not where it'd ideally be, but I'm limited by cable length. When I had a longer cable, the cable loss was greater than the gain from higher elevation. The FR24 antenna, however, is well clear of the TV antenna:
                              ADSB_Antenna_Small.jpg

                              Comment


                              • Originally posted by Ressy View Post
                                HUH?

                                Only the deep grey type blocks RF, the off white, white, light grey, don't, I think orange doesnt either - but that would look ridiculous. Bunnings or Masters should be able to help you.
                                Ohhh? Hmmm, I read it as though any PVC blocked RF, I read it like that because it wasn't specified on a per-colour basis.. I am presently using the white high pressure PVC as I figured over a ~2mtr length it would be the least likely to flap about when it gets windy, normally that wouldn't matter too much, but on the same mast I have 3 weather cameras and if I get too much movement in the mast then the images get wobbly as well... (each camera mounting bracket and both brackets holding the 1090 coco up have their own guy wires as well)
                                T-YBBN50 - Kallangur, QLD, Australia

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