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Old 7th October 2012, 02:32 PM
Brad B Brad B is offline
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Join Date: Jul 2012
Location: Outer West Sydney
Posts: 41
Default Antenna Grounding

Hi Guys, I have blown 2 boxes from static and i need to ground/earth my antenna to stop this happening...can anyone help?

I have had some good ideas from members here and thank you but my problem is, the antenna is on a PVC mast and the antenna is not conductive to any part of the other antennas and metal mast...how would i earth the ADS-B antenna id it is not conductive to the main mast??

Would a DC block be the only way?? I need to earth it so I dont pop more boxes!

see attached pic.

thank you

B
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Old 11th October 2012, 04:58 PM
Mike Scott Mike Scott is offline
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Join Date: Mar 2008
Location: HNL Hawaii USA
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Default

First thing to do obviously is DON'T hook up your receiver to that outside antenna again...at least until you have a rudimentary grounding system in place. Given the location (based on your pic) its perched high up above everything else and is insulated (by your PVC pole)from everything else that might otherwise act at least as a partial ground and dissipate some of the static electricity build up on your antenna and coax which is bottom line the cause of your problem.

Other than lightning storms (even in the mid/near area) static electricity build up (caused by wind/blowing dust/rain hitting your antenna and coax) is your biggest problem...and right now the only way for it to dissipate (once it gets to a certain potential) is straight down your coax and through your ADSB box which is in turn connected to power...and so to a ground. Your antenna in its current form is like a static beacon out there attracting everything around it...right into your house....which is not where you want it !!!
Do you have a Volt/Ohm meter....if not get one from hardware or an electrical store...doesn't need to be a fancy one...need to be able to read resistance and conductivity...and beep when you have a short...

Longer term solution isn't easy...you may have to think about bringing the antenna down a bit...you don't need it up there anyway...planes you are receiving from are 30,000 ft plus in the air....don't need a high physical antenna for those...you do need a higher gain antenna and a few other tricks to bring a stronger signal to your receiver....its like collecting water...the bigger the funnel (collector)....the more water your going to have in the bucket...so definitely some things that need to be done to make your set up as safe electrically as possible....yet provide that increased signal gain in the receiving path that you need.

I just sent you an email with some additional detail and a few links that should get you started on a basic grounding system that will take the static electricity away from your receiver and send it to ground. This subject matter can get really long and complicated (too long for these forums) Looks like Mods are putting together a ADSB day/weekend or something ...you might want to go along.. Also I am working a Sydney trip late next week then will take a short holiday break on the Gold Coast so I can always give you a ring from there and see what progress your making.

Yes you definitely have a problem but its not one that cant be solved..at least for the most part. There is no getting away from damage via a direct or very close lightning strike. Keep your ear on the weather forecasts...if thunderstorms are mentioned then disconnect your equipment from both antenna and power...and make sure your antenna cable is lying on the ground outside if you don't have a proper grounding system in place.

MS
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