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  • Originally posted by abcd567 View Post
    If you do not have an electronics parts shop nearby, you can order Splitter, Capacitor & Inductor on Line very cheap, but will have to wait 1 to 2 months due to surface/sea shipping from China:

    1 Pc, 2-WAY CABLE TV SPLITTER 5-900MH - FREE Standard Int'l Shipping - US $1.49
    http://www.ebay.ca/itm/2-WAY-CABLE-T...-/280766417601

    30 Pcs 220pF 50V Ceramic Disc Capacitor - Free Shipping - US $0.99
    http://www.ebay.ca/itm/30-Pcs-220pF-...g/321028278208

    10 Pcs 4.7 uH Inductor 1/2W - FREE Standard Int'l Shipping - US $1.49
    http://www.ebay.ca/itm/10-x-4-7uH-4-...-/330452964551
    Wow good find ... you really can't get any cheaper that this and free shipping all the way from ZHEJIANG, China !
    www.ADS-B.ca

    Comment


    • Could you also add a neon bulb across the output to and make it into a lightening discharge device?
      - would it work?

      Comment


      • Originally posted by peterhr View Post
        Could you also add a neon bulb across the output to and make it into a lightening discharge device?
        - would it work?
        I have never thought of adding a lightening discharge device as my installation is strictly Indoors.
        I will have to do some study & research to find answer to your question.
        I will come back to you later if I find an answer.

        Comment


        • "lightening protection " is an absolute waste of time and effort (and signal)
          If you are struck, NOTHING will protect your gear.
          Perhaps were are talking about "static" protection... in which case, depending on antenna type... Or the fact you have added an amplifier, or even leaving it connected to the reciever (yes, I know this sounds counterintuitive) will provide a discharge path for and static build up.
          Adding a neon lamp will prevent the voltage building to maybe 60/80 volts, but if it gets that high your front end will already be toast.
          I've had antennae higher than my house for 30 years, and never lost a receiver... And my antennae are a LOT bigger than a coco! lol

          Sent using Tapatalk from my ZX81

          Comment


          • Originally posted by Rooster View Post
            "lightening protection " is an absolute waste of time and effort (and signal)
            If you are struck, NOTHING will protect your gear.
            Perhaps were are talking about "static" protection... in which case, depending on antenna type... Or the fact you have added an amplifier, or even leaving it connected to the reciever (yes, I know this sounds counterintuitive) will provide a discharge path for and static build up.
            Adding a neon lamp will prevent the voltage building to maybe 60/80 volts, but if it gets that high your front end will already be toast.
            I've had antennae higher than my house for 30 years, and never lost a receiver... And my antennae are a LOT bigger than a coco! lol

            Sent using Tapatalk from my ZX81
            You are right Rooster.
            -.-- --- ..- / .- .-. . / .-. .. --. .... - / .-. --- --- ... - . .-.

            Lightning protection requires a separate lightning protection system for the building, and even then protection is not guaranteed. See below sketch & quote from wikipedia:

            uploadfromtaptalk1393989622073.jpg

            "Because of the high energy and current levels associated with lightning (currents can be in excess of 150,000 amps), and the very rapid rise time of a lightning strike, no protection system can guarantee absolute safety from lightning. Lightning current will divide to follow every conductive path to ground, and even the divided current can cause damage. Secondary "side-flashes" can be enough to ignite a fire, blow apart brick, stone, or concrete, or injure occupants within a structure or building. However, the benefits of basic lightning protection systems have been evident for well over a century."

            .
            Last edited by abcd567; 2014-03-05, 03:58.

            Comment


            • Originally posted by Rooster View Post
              "lightening protection " is an absolute waste of time and effort (and signal)
              If you are struck, NOTHING will protect your gear.
              Perhaps were are talking about "static" protection... in which case, depending on antenna type... Or the fact you have added an amplifier, or even leaving it connected to the receiver (yes, I know this sounds counterintuitive) will provide a discharge path for and static build up.
              Adding a neon lamp will prevent the voltage building to maybe 60/80 volts, but if it gets that high your front end will already be toast.
              I've had antennae higher than my house for 30 years, and never lost a receiver... And my antennae are a LOT bigger than a coco! lol

              Sent using Tapatalk from my ZX81
              Lightning protection is not a complete waste of time. I am a radio and communication professional and we have towers and antennas that take direct strikes frequently with no issues. It just depends on the level of protection you can afford and justify for the system you have installed.

              For our purpose of discussion here the main thing you need is a grounding block on the feed line that takes the coax shield and connects it to your other grounds and the earth. Proper bonding (connecting all grounds together) and then making sure you have a good common earth ground for all electrical and communication equipment is key to doing the best you can at protecting your equipment and the station (house, building, shack, etc) itself. Besides, this is required in the US and many countries per the electrical code. While this will not protect your equipment from a direct strike it will at least provide a good path to ground for any electrical surges caused by lightning strikes close to the station and help protect your home from having lighting surge through the house looking for a better path to ground.
              Last edited by HighlyCool; 2014-03-05, 14:19.

              Comment


              • I have a pole attached to the wall of the house, grounded using a 10mm cross section conductor to a 4' spike in the ground - I'm not particularly trying to protect the dongle or the pi (they are disposable) - I just hope to protect the rest of the house should the pole take a strike.

                The (very near) neighbours have a TV antenna on the chimney ... they would probably share any strike.

                Comment


                • Originally posted by peterhr View Post
                  Could you also add a neon bulb across the output to and make it into a lightening discharge device?
                  - would it work?

                  Originally posted by Rooster View Post
                  "lightening protection " is an absolute waste of time and effort (and signal)
                  If you are struck, NOTHING will protect your gear.
                  Perhaps were are talking about "static" protection... in which case, depending on antenna type... Or the fact you have added an amplifier, or even leaving it connected to the reciever (yes, I know this sounds counterintuitive) will provide a discharge path for and static build up.
                  Adding a neon lamp will prevent the voltage building to maybe 60/80 volts, but if it gets that high your front end will already be toast.
                  I've had antennae higher than my house for 30 years, and never lost a receiver... And my antennae are a LOT bigger than a coco! lol

                  Sent using Tapatalk from my ZX81
                  Originally posted by HighlyCool View Post
                  Lightning protection is not a complete waste of time. I am a radio and communication professional and we have towers and antennas that take direct strikes frequently with no issues. It just depends on the level of protection you can afford and justify for the system you have installed.

                  For our purpose of discussion here the main thing you need is a grounding block on the feed line that takes the coax shield and connects it to your other grounds and the earth. Proper bonding (connecting all grounds together) and then making sure you have a good common earth ground for all electrical and communication equipment is key to doing the best you can at protecting your equipment and the station (house, building, shack, etc) itself. Besides, this is required in the US and many countries per the electrical code. While this will not protect your equipment from a direct strike it will at least provide a good path to ground for any electrical surges caused by lightning strikes close to the station and help protect your home from having lighting surge through the house looking for a better path to ground.
                  Originally posted by peterhr View Post
                  I have a pole attached to the wall of the house, grounded using a 10mm cross section conductor to a 4' spike in the ground - I'm not particularly trying to protect the dongle or the pi (they are disposable) - I just hope to protect the rest of the house should the pole take a strike.

                  The (very near) neighbours have a TV antenna on the chimney ... they would probably share any strike.
                  Download & Read this Document:

                  How to Protect Your House and Its Contents from Lightning

                  IEEE** Guide for Surge Protection of Equipment Connected to AC Power and Communication Circuits, Published by Standards Information Network, IEEE Press.

                  **IEEE = Institute of Electrical & Electronic Engineers of North America


                  .
                  Last edited by abcd567; 2014-03-05, 22:47.

                  Comment


                  • Here is an interesting read, on how Ham Radio Op's are using many of the various receivers and software for 'Airplane Scatter' ! FR24, 'ModeS beast', etc. mentioned..along with 'many other Hardware/Software' versions. Mainly used in the 'micro wave bands'..but I have used Airplane Scatter on 50, 144, and 432Mhz many times ! 73 enjoy
                    VE6CPP
                    F-CYQL1
                    http://www.nitehawk.com/w3sz/AircraftScatter.htm#Top

                    Comment


                    • Originally posted by VE6CPP View Post
                      Here is an interesting read, on how Ham Radio Op's are using many of the various receivers and software for 'Airplane Scatter' ! FR24, 'ModeS beast', etc. mentioned..along with 'many other Hardware/Software' versions. Mainly used in the 'micro wave bands'..but I have used Airplane Scatter on 50, 144, and 432Mhz many times ! 73 enjoy
                      VE6CPP
                      F-CYQL1
                      http://www.nitehawk.com/w3sz/AircraftScatter.htm#Top
                      Very interesting & informative. Thanks for sharing Jerry. 73

                      Comment


                      • Airplane Scatter can also be a bad thing by causing multipath interference. This phenomenon is known as Airplane Flutter and is best known for causing a fluttering picture interference lasting only a few seconds to analog TV reception as a plane passes nearby. Digital TV is not immune to Airplane flutter as I've seen it happen with my own TV and the reason I used a stacked antenna.

                        Years ago when I had a house in Jamaica I started to notice the connection between a few seconds of a flickering picture on my TV and then hearing an Aircraft pass in the distance. Sure enough what I discovered was as an Aircraft would take off about 5Km away it would send a reflected signal and cause the Airplane flutter interference I was seeing. I started to put it to good use, and when I would see the flutter I would walk out on the porch and and watch the plane going out over the ocean into the sunset.

                        http://2003.iccas.org/Full_Paper/air..._5%2819%29.pdf
                        www.ADS-B.ca

                        Comment


                        • Originally posted by HighlyCool View Post
                          Lightning protection is not a complete waste of time. I am a radio and communication professional and we have towers and antennas that take direct strikes frequently with no issues. It just depends on the level of protection you can afford and justify for the system you have installed.
                          I second that. I'm also a professional, and used to do engineering / technical work for several radio and TV broadcasters in the Chicago area. I've seen lightning hit a TV mast on Sears Tower and have no effect on the dozen or so transmitters there. And I've seen the protection systems that are used to do it. When there's millions of dollars of custom made equipment on the line, as well as thousands of dollars per minute of lost revenues in jeopardy, there is a way to mitigate direct lightning strikes. Conversely, if your budget and risk is significantly lower than a major broadcaster, you're not likely to consider such a comprehensive and costly protection system for yourself. But something can be done for any budget.

                          I agree that national and local electric codes should be obeyed. I'd go on further to say that if you did nothing to protect your home from any kind of damage that could be done to your home from an external antenna (be it as minor falling over and breaking a window, or as major as falling onto electrical cables and burning the house down...and lightning strikes), that your insurance company might use that as an excuse to not pay for the damages. Lots of good reasons to consider the entire scope of possible safety hazards and take reasonable measures to prevent them.

                          IMO this is one area where hiring a licensed electrical contractor to do the work can be mighty cheap insurance. IJS

                          Comment


                          • Originally posted by Speed Daemon View Post
                            I second that. I'm also a professional, and used to do engineering / technical work for several radio and TV broadcasters in the Chicago area. I've seen lightning hit a TV mast on Sears Tower and have no effect on the dozen or so transmitters there. And I've seen the protection systems that are used to do it. When there's millions of dollars of custom made equipment on the line, as well as thousands of dollars per minute of lost revenues in jeopardy, there is a way to mitigate direct lightning strikes. Conversely, if your budget and risk is significantly lower than a major broadcaster, you're not likely to consider such a comprehensive and costly protection system for yourself. But something can be done for any budget.

                            I agree that national and local electric codes should be obeyed. I'd go on further to say that if you did nothing to protect your home from any kind of damage that could be done to your home from an external antenna (be it as minor falling over and breaking a window, or as major as falling onto electrical cables and burning the house down...and lightning strikes), that your insurance company might use that as an excuse to not pay for the damages. Lots of good reasons to consider the entire scope of possible safety hazards and take reasonable measures to prevent them.

                            IMO this is one area where hiring a licensed electrical contractor to do the work can be mighty cheap insurance. IJS
                            The first step in preventing damage to building & radio equipment is to divert lightning from hitting antenna directly.
                            Preventing a direct hit requires providing an alternate target on the tower or building for the lightning to strike. This requires the installation of a lightning rod or equivalent at a higher elevation than the antenna.

                            Second step is to prevent lightning current from passing through building structure and coaxial cable.
                            This is done by providing lightning current an alternate effective path to earth by connecting the lightning rod and antenna mast to ground by means of a copper strip/wire of sufficiently high cross-section and a set of earthing rods.

                            Please note that implementing ONLY STEP-1 OR ONLY STEP-2 is not sufficient. Step 1 & 2 are effective only when BOTH are implemented.

                            Even without a direct hit, a lightning strike nearby induces a strong electromagnetic field that may still cause damage to equipment. The third step in lightning protection is to use surge protection devices to protect the radio and other equipment.

                            Lightning Protection System-1.JPG


                            Lightning Protection System 2.jpg
                            .
                            Last edited by abcd567; 2014-03-12, 18:04.

                            Comment


                            • Originally posted by abcd567 View Post
                              The first step in preventing damage to building & radio equipment is to divert lightning from hitting antenna directly.
                              Preventing a direct hit requires providing an alternate target on the tower or building for the lightning to strike. This requires the installation of a lightning rod or equivalent at a higher elevation than the antenna.
                              That's how it's done with $million broadcast antenna arrays. For a $100 home antenna that isn't mission critical, simply letting the antenna get fried, then replacing it can be more cost effective. Personally I'd concentrate my money on stopping the surge at or before the house entry point.


                              Second step is to prevent lightning current from passing through building structure and coaxial cable.
                              This is done by providing lightning current an alternate effective path to earth by connecting the lightning rod and antenna mast to ground by means of a copper strip/wire of sufficiently high cross-section and a set of earthing rods.
                              Proper grounding is important, but when you consider how far lightning travels before it gets to your antenna mast, it's a tad naive to think that you are in control of its path. The real key here is to have enough sheer mass to be able to absorb the lightning bolt without significant damage. For broadcast towers and masts, this mass comes from the tons of steel that they're made of. For home installations it's a good reason to not skimp on building materials. Once again, if you're building an antenna mast on or near your home, the investment should be in a good lightning protection system for the house first and foremost. Better to warp a $100 mast than burn down a $100,000 house.


                              Even without a direct hit, a lightning strike nearby induces a strong electromagnetic field that may still cause damage to equipment. The third step in lightning protection is to use surge protection devices to protect the radio and other equipment.
                              This is why you're not supposed to touch anything connected to long runs of wire or pipe during an electrical storm. A lightning strike down the street can induce lethal currents into any sort of conductor, including wires that aren't connected to "electricity"...even the water in plastic pipes. (Note that it's the dissolved salts in the water that make it conductive. Hard water is conductive water.)

                              It's also a good reminder that it's better to play it safe, and not tempt fate by thinking that there is any such thing as "lightning proof".

                              Comment


                              • Originally posted by Speed Daemon View Post
                                .........but when you consider how far lightning travels before it gets to your antenna mast, it's a tad naive to think that you are in control of its path. The real key here is to have enough sheer mass to be able to absorb the lightning bolt without significant damage................
                                In my previous post, I have posted 2 sketches:

                                Single protection Lightning Protection System-1.JPG

                                Multiple protection Lightning Protection System 2.jpg

                                Single protection is cost effective, but still there is substantial chance of damage by lightning bolt.

                                With Multiple Protection System, there is very little chance that any appreciable part of lightning bolt will hit & go through building structure. This is due to the fact that there are enough number of parallel paths provided by large number of lightning rods, copper down strips/wires and earth rods, all bonded together at roof level as well as ground level. This is equivalent to what you call "sheer mass".

                                Comment

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