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  • Some good news after updating to latest Rpi 16-7 is that some ground vehicles are showing at YBBN. Not sure why all possible ground vehicles are not showing. Anyone want to try upgrade at YSSY to check there?

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    • Originally posted by YSWG View Post
      There has been a few posts in different threads. F = FR24 box (Radarcape based) and T = Raspberry Pi [RPi], PC, Android phone using the USB dongle.

      I operate both F-YSWG1 and T-YSWG2 (RPi 2 Model B), F picks up further but is also more stable with the signals from aircraft and T is about 20% less with what it picks up and not as stable (since we are asking a lot for a USB stick, software and DIY antenna).

      Range of F-YSWG1 and T-YSWG2 with VRS. T has some spikes which I've yet to remove (unsure why it happened when I had measures to prevent such spikes)
      [ATTACH=CONFIG]6730[/ATTACH][ATTACH=CONFIG]6729[/ATTACH]
      Hey YSWG,

      I have a thought on this.. When I started doing this whole RTL-SDR dump1090 thing it was with a Pi B+ ... Then when all the MLAT stuff started happening increasing load on the Pi I figured I would switch to a Pi2 .. Here's the kicker, when I did that, I got slugged with about the same amount of decrease in positions as you are seeing, about 20% loss.. I immediately switched back to the Pi B+ and things went back to normal. My very first thought was the Pi2 obviously generates a whole lot of extra RF. I left it at that until a few nights ago I decided to look at how to shield the dongle from the RF of the Pi2.. Apparently disconnecting the ground shield in the USB cable generates a big improvement, adding a ferrite core to the positive of the USB cable as well also helps to damp down the RF...

      So far none of this I can try as my Pi B+ and mini RTL-SDR dongle is in a small polycarb box on the roof, so there is not a lot of room.. About 2 days ago I decided to raise my antenna by 1mtr (the base of the antenna was only about 1mtr about the peak of the roof, I've increase position count by about 1/3 and now I can see down to about 25ft off YBBN RWY01.. This has increased the number of concurrent planes I can see as well, which has increased load on the CPU, which means FA sometimes drop me out of MLAT positioning due to load, I've temporarily combated this by pushing the Pi B+ into turbo mode (I say temporary as I expect to burn it out in short order at high clock speeds).. But what I will need to do is bring the Pi and dongle down off the roof, and separate them, putting them both in separate steel cases, inside the case will be the shield disconnected USB cable.. And if I can get a decent sized metal box I will leave room for an LNA/SAW filter combo in the same box.. I will then switch to a Pi2 putting it in yet another steel box.. I also plan on raising my antenna another 3mtrs... Then I should get some decent range, currently with just a 16 element coco connected directly to the SDR dongle I am seeing upto 380km... Hopefully can improve on that..
      T-YBBN50 - Kallangur, QLD, Australia

      Comment


      • Originally posted by bhaal View Post
        Hey YSWG,

        I have a thought on this.. When I started doing this whole RTL-SDR dump1090 thing it was with a Pi B+ ... Then when all the MLAT stuff started happening increasing load on the Pi I figured I would switch to a Pi2 .. Here's the kicker, when I did that, I got slugged with about the same amount of decrease in positions as you are seeing, about 20% loss.. I immediately switched back to the Pi B+ and things went back to normal. My very first thought was the Pi2 obviously generates a whole lot of extra RF. I left it at that until a few nights ago I decided to look at how to shield the dongle from the RF of the Pi2.. Apparently disconnecting the ground shield in the USB cable generates a big improvement, adding a ferrite core to the positive of the USB cable as well also helps to damp down the RF...

        So far none of this I can try as my Pi B+ and mini RTL-SDR dongle is in a small polycarb box on the roof, so there is not a lot of room.. About 2 days ago I decided to raise my antenna by 1mtr (the base of the antenna was only about 1mtr about the peak of the roof, I've increase position count by about 1/3 and now I can see down to about 25ft off YBBN RWY01.. This has increased the number of concurrent planes I can see as well, which has increased load on the CPU, which means FA sometimes drop me out of MLAT positioning due to load, I've temporarily combated this by pushing the Pi B+ into turbo mode (I say temporary as I expect to burn it out in short order at high clock speeds).. But what I will need to do is bring the Pi and dongle down off the roof, and separate them, putting them both in separate steel cases, inside the case will be the shield disconnected USB cable.. And if I can get a decent sized metal box I will leave room for an LNA/SAW filter combo in the same box.. I will then switch to a Pi2 putting it in yet another steel box.. I also plan on raising my antenna another 3mtrs... Then I should get some decent range, currently with just a 16 element coco connected directly to the SDR dongle I am seeing upto 380km... Hopefully can improve on that..
        Very interesting. If only I knew what RF is.

        Comment


        • My RPi 2 is located in the weather proof housing with the powerpoint (which could cause RF, along with the power adapters for the RPi and FR24 box) and RTL-SDR dongle is connected to a 10m USB2 cable with the RTL-SDR dongle in a Inspection Tee Conduit with a lot of duct tape [sealing pipe the holes], which then connects to 15m of coax to the 8 element CoCo. If I get a chance, I'll draw up a diagram.

          Originally posted by Kpin View Post
          Very interesting. If only I knew what RF is.
          Radio frequency interference (RFI), but a lot of people use RF in short. Even powerlines have RF, which you can sometimes hear on an AM radio.
          Last edited by YSWG; 2015-12-21, 08:35.
          F-YSWG1 and T-YSWG2

          Comment


          • Originally posted by YSWG View Post
            My RPi 2 is located in the weather proof housing with the powerpoint (which could cause RF, along with the power adapters for the RPi and FR24 box) and RTL-SDR dongle is connected to a 10m USB2 cable with the RTL-SDR dongle in a Inspection Tee Conduit with a lot of duct tape [sealing pipe the holes], which then connects to 15m of coax to the 8 element CoCo. If I get a chance, I'll draw up a diagram.
            The shield connection in the USB cable will also act as an antenna, not only carrying any RF from the Pi2's ground plane up the line but also amplifying any other nearby sources and channeling that into the RTL-SDR dongle. A USB2 cable only requires 4 wires, which are the 4 pins you see in the connectors, but there is normally also a shield to shield connection either as foil wrapped around the 4 wires, or a non-insulated stranded wire.

            This is a bit extreme but will give you the idea of what I mean:

            Leif, the programmer of Linrad has recently uploaded a video to YouTube showing how he shields his RTL-SDR dongles to prevent the USB shield from acting as an antenna and picking up unwanted signals. In the video he also measures how well various other SDRs are at avoiding USB shield interference. From the video we can see that Leif's shielding method uses the following steps: The metal box is RF tight and held together by many screws. The USB shield and external antenna connector shields are both connected to the box. The USB 5V line is decoupled to the GND line. The USB 5V



            EDIT: Oh Oh! (not Ho Ho) Also, something I forgot to mention, the FR24box has a decent LNA built into the 1090mhz receiver.. Not sure about a SAW filter though... So this will also greatly increase range...

            Originally posted by YSWG View Post
            Radio frequency interference (RFI), but a lot of people use RF in short. Even powerlines have RF, which you can sometimes hear on an AM radio.
            Thanks for clearing that up, for a moment there I second guessed myself, I am not a major radio nut so I figure sometimes I am going to get my terminology wrong. But I do understand some of the basic concepts of interference.

            I am a little bit of a maker, getting all the gear working nicely is the fun part (although sometimes frustrating), seeing the data coming from the planes is a bonus

            Merry Christmas for those who celebrate it!
            Last edited by bhaal; 2015-12-21, 14:33.
            T-YBBN50 - Kallangur, QLD, Australia

            Comment


            • Originally posted by bhaal View Post
              This is a bit extreme but will give you the idea of what I mean:

              Leif, the programmer of Linrad has recently uploaded a video to YouTube showing how he shields his RTL-SDR dongles to prevent the USB shield from acting as an antenna and picking up unwanted signals. In the video he also measures how well various other SDRs are at avoiding USB shield interference. From the video we can see that Leif's shielding method uses the following steps: The metal box is RF tight and held together by many screws. The USB shield and external antenna connector shields are both connected to the box. The USB 5V line is decoupled to the GND line. The USB 5V


              a B I T extreme??? that's overkill of overkill - Unless of course he lives on or adjacent to whats known as an "RF mountain" (ours for example is Mt Coot-tha (incl high parts of Bardon, Red Hill), or on top of Waterfront Place) then yes, that would be a minimum setup.

              Merry Christmas.

              Comment


              • Well I live within 500mtrs of our local water tower which has an unhealthy coating of cell phone transceivers, and then about 1.8km in the opposite direction is another well populated cell tower... So there is a reasonable amount of RF noise about the place, cannot wait till I add the filter and amp to my rig, and all the shielding mods, though not to the extreme of that copper based case haha... Probably mid year before it's complete I'd say...
                T-YBBN50 - Kallangur, QLD, Australia

                Comment


                • Originally posted by bhaal View Post
                  Well I live within 500mtrs of our local water tower which has an unhealthy coating of cell phone transceivers, and then about 1.8km in the opposite direction is another well populated cell tower... So there is a reasonable amount of RF noise about the place, cannot wait till I add the filter and amp to my rig, and all the shielding mods, though not to the extreme of that copper based case haha... Probably mid year before it's complete I'd say...
                  500 mtrs wont be too bad at cell levels, unless they also have lots commercial gear as well, which can radiate much higher, 50 watts with 6-9db antennas and then there'd have to be a fair bit of it, and stuff that needs be close to an image, IOW, generally cell towers arent a problem.

                  I cant see you gaining any advantage by overkill grounding since your not in a high RF zone, height will be your best advantage, along with masthead amplifier

                  Comment


                  • Originally posted by Ressy View Post
                    500 mtrs wont be too bad at cell levels, unless they also have lots commercial gear as well, which can radiate much higher, 50 watts with 6-9db antennas and then there'd have to be a fair bit of it, and stuff that needs be close to an image, IOW, generally cell towers arent a problem.
                    Well I am getting a reasonable number of positions, given my antenna height, the base is 5mtrs above ground and ground is 35mtrs, the antenna itself is 2mtrs in height..

                    Originally posted by Ressy View Post
                    I cant see you gaining any advantage by overkill grounding since your not in a high RF zone, height will be your best advantage, along with masthead amplifier
                    If I can get my antenna up another or 4mtrs should put it above the height of the 2 storey houses around me... I am aiming specifically to use a 1090Mhz amp, and I haven't seen any which would be masthead mountable...

                    I have one other minor concern.. Lightning... Any recommendation on lightning suppressors? I have a lot of gear down wire of this antenna that I'd rather not have fried and short of air gapping with a wifi dongle (I hate wifi given it's lack of reliability), but that doesn't air gap the power source, the dump1090 Pi shares the same power socket as 3 weather cams and a half dozen cctv cameras, none of which I want fried. Whats the best option? Do gas tube arresters still need grounding? Just worried about insertion loss :/ HALP
                    T-YBBN50 - Kallangur, QLD, Australia

                    Comment


                    • Originally posted by bhaal View Post
                      Well I am getting a reasonable number of positions, given my antenna height, the base is 5mtrs above ground and ground is 35mtrs, the antenna itself is 2mtrs in height..



                      If I can get my antenna up another or 4mtrs should put it above the height of the 2 storey houses around me... I am aiming specifically to use a 1090Mhz amp, and I haven't seen any which would be masthead mountable...
                      yeah, I have a problem with past twelve months with all the wet weather, the nearby trees have grown much higher, so I've lost out some distance low level stuff in a couple directions, and that two storey house behind me is still there so I'll never get under 900 ft YBBN, I do get down to 100ft at YRED though.. thinking about moving the antenna to other side of house but theres already a number of T&F feeders who get ground at YBBN so I probably wont bother

                      Originally posted by bhaal View Post
                      I have one other minor concern.. Lightning... Any recommendation on lightning suppressors? I have a lot of gear down wire of this antenna that I'd rather not have fried and short of air gapping with a wifi dongle (I hate wifi given it's lack of reliability), but that doesn't air gap the power source, the dump1090 Pi shares the same power socket as 3 weather cams and a half dozen cctv cameras, none of which I want fried. Whats the best option? Do gas tube arresters still need grounding? Just worried about insertion loss :/ HALP
                      The loss would be minimal, maybe 2db, but if its a direct strike, it'll be the luck of the draw as to how much damage occurs, I've seen it where on commercial two way radios where transmitter stages are fried, but the receiver was untouched, also seen some totally disintegrate the insides, make sure its a class 1 device (firing level of 500v) and yes it must be earthed - ideally to a protected earth off your switchboard (you cant touch) or the ground stake (grey area for touching, either way you must not ever break that connection, you can clamp to it tho, I know certified/registered telco techs are allowed to do it, unless the laws changed I dont think "joe avg" can - I'll let any aussie sparkies reading this answer that one since theyd be more up on that area), and use minimum of 6mm sq earth (green/yellow) cable to that point.

                      Comment


                      • Originally posted by Ressy View Post
                        yeah, I have a problem with past twelve months with all the wet weather, the nearby trees have grown much higher, so I've lost out some distance low level stuff in a couple directions, and that two storey house behind me is still there so I'll never get under 900 ft YBBN, I do get down to 100ft at YRED though.. thinking about moving the antenna to other side of house but theres already a number of T&F feeders who get ground at YBBN so I probably wont bother
                        I don't watch FR24 or FA much, I watch everything locally on VRS, so I am keen to see down to GND at the locals, I still may not due to the actual airport buildings, but I'm gonna give it a good shot. I can see down to 50ft at YRED, and not really sure about YCAB, somewhere between 50 and 200ft I think, don't see a lot of transponder equipped aircraft use that AP... Oh, and I can also almost see the helipad at RBWH...

                        Originally posted by Ressy View Post
                        make sure its a class 1 device (firing level of 500v) and yes it must be earthed - ideally to a protected earth off your switchboard (you cant touch) or the ground stake (grey area for touching, either way you must not ever break that connection, you can clamp to it tho, I know certified/registered telco techs are allowed to do it, unless the laws changed I dont think "joe avg" can - I'll let any aussie sparkies reading this answer that one since theyd be more up on that area), and use minimum of 6mm sq earth (green/yellow) cable to that point.
                        I was given an arrester a few years back, it was used with 2.4ghz wireless, I am not sure what it's lower frequency range is, will have to find it and check it's stats before I go buy something.. As for the earth, I was thinking of putting down a separate ground spike to try and keep it as far away from everything else as possible... Where should the arrester be placed though? Directly below the antenna, or can I put it in a roof level to limit the length of earthing cable that would be required. The antenna will be 4 or 5 metres above roof height, so it's a lot of extra cable... Sooo many questions..

                        Also.. We need someone in the Redcliffe area.. I have an MLAT blindspot locally to me below 1500ft .. And that's very annoying when I am trying to watch specifically where Polair2 is So someone in Redcliffe preferrably with a western view to me would be ideal, as it's about the perfect distance from me for MLAT to be reasonably accurate...
                        Last edited by bhaal; 2015-12-23, 02:16.
                        T-YBBN50 - Kallangur, QLD, Australia

                        Comment


                        • Here's a little bit of Qantas weirdness ... Firstly, the route....what the? Secondly, I guess something has gone wrong:

                          weirdqantas.jpg
                          T-YBBN50 - Kallangur, QLD, Australia

                          Comment


                          • Originally posted by Ressy View Post
                            ............. but if its a direct strike, it'll be the luck of the draw as to how much damage occurs .....
                            yuuuup - had a direct strike on a palm tree next door - surprisingly, only thing it took out was any active ethernet port on my LAN - anything that had an active ethernet port, the port got zapped; took out the ethernet ports on my TV, server, an Arduino and the active ports on the LAN side of my router. Interestingly, the ADSL modem and the WAN ethernet port of the router survived !!???

                            having worked in the broadcast transmission game - the only industry where you go and put a 400ft metal lightning attractor on a mountain top - I've seen some weird ass effects of a direct strike and often it doesn't matter how well you earth things - if mother nature wants to fry your piece of kit, she will !!
                            Last edited by rodeo; 2015-12-23, 11:15. Reason: typos galore!!
                            T-YSBK22

                            Comment


                            • Originally posted by rodeo View Post
                              yuuuup - had a direct strike on a palm tree next door - surprisingly, only thing it took out was any active ethernet port on my LAN - anything that had an active ethernet port, the port got zapped; took out the ethernet ports on my TV, server, an Arduino and the active ports on the LAN side of my router. Interestingly, the ADSL modem and the WAN ethernet port of the router survived !!???

                              having worked in the broadcast transmission game - the only industry where you go and put a 400ft metal lightning attractor on a mountain top - I've seen some weird ass effects of a direct strike and often it doesn't matter how well you earth things - if mother nature wants to fry your piece of kit, she will !!
                              I don't mind too much if she fries the antenna and Pi it's connected to, but damn I'd like to limit to that, but it wouldn't be likely being that I have cat5e running around the outside of the house under the eaves... But yeah, you are right, a big enough strike is going to blast a whole through the house if it wants to... But if I can get some protection than I'll take it and hope it works... The next question, by adding an arrester and connecting it to ground, am I more likely to attract a strike?
                              T-YBBN50 - Kallangur, QLD, Australia

                              Comment


                              • Originally posted by bhaal View Post
                                As for the earth, I was thinking of putting down a separate ground spike to try and keep it as far away from everything else as possible... Where should the arrester be placed though? Directly below the antenna, or can I put it in a roof level to limit the length of earthing cable that would be required. The antenna will be 4 or 5 metres above roof height, so it's a lot of extra cable... Sooo many questions..
                                We were taught to use the buildings electrical ground system, as a separate rod wont do much good due to the electrical potential rise that would occur with such high power of a strike, we put the arrestors close to equipment or where cables enter the building, not up the masts, so roof level (assuming thats where it enters the building) would be fine.

                                Originally posted by bhaal View Post
                                Also.. We need someone in the Redcliffe area.. I have an MLAT blindspot locally to me below 1500ft .. And that's very annoying when I am trying to watch specifically where Polair2 is So someone in Redcliffe preferrably with a western view to me would be ideal, as it's about the perfect distance from me for MLAT to be reasonably accurate...
                                We have a lot of people covering YRED, but I suspect they are windows feeders or regular dump1090 users like myself, I know T 1, 27 and I think 29 and Sunny Coast 2 also sees ground or very close to it at YRED, FR24 are severely limiting themselves for only supporting mlat on pi's

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