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Static from Antenna

Posted: Thu Jan 24, 2019 11:46 pm
by illllm
Hi All,

I have a loop antenna mounted outside. Its been very cold and dry these days. Today morning, and multiple times after, i received a static shock when i touched the coax to connect it to the RSP2. Should i be concerned ? Do i have to add some protection from antenna to receiver?

thanks much!

Re: Static from Antenna

Posted: Fri Jan 25, 2019 5:24 am
by Fractal1
It is unusual to be getting static build up to that degree on a loop, generally random/long wire antennas can generate quite a bit which is always discharged to earth before it gets to the reciever. How is your set up earthed?

Re: Static from Antenna

Posted: Fri Jan 25, 2019 1:46 pm
by illllm
The loop sits on my balcony. Its earthed to the shield only when its connected ( or when i touch it :o :oops: )

Re: Static from Antenna

Posted: Sat Jan 26, 2019 1:28 am
by Mike2459
Illllm:

You were likely the source of the static charge!! Unless you wear a pacemaker I wouldn't be too concerned. Unless you are doing work on a circuit, the electronics should be OK too, not a lot of energy stored in these sorts of discharges.

Re: Static from Antenna

Posted: Sat Jan 26, 2019 1:41 am
by illllm
i think you might be correct. I zap everything i touch in winter.

That being said, do i need to protect the front end from overload/overvoltage ? Would it be okay to use an LNA ?

Re: Static from Antenna

Posted: Sat Jan 26, 2019 6:52 am
by Paul
Just a thought...
Do you have any nylon in your floor-covering?

Re: Static from Antenna

Posted: Sat Jan 26, 2019 6:52 pm
by illllm
The floor is carpet, which is nylon i guess.

Re: Static from Antenna

Posted: Sat Jan 26, 2019 8:44 pm
by Paul
Perhaps the cause or crontributor to your static problem (particularly in cold weather Ibieve) - Just walking on the carpet would be sufficient i think.

Re: Static from Antenna

Posted: Sat Jan 26, 2019 10:39 pm
by arcosine
Put a resistor to ground, something like 100k ohm . It will bleed the static without affecting the signal. The spark could destroy your sdr.

Re: Static from Antenna

Posted: Sun Jan 27, 2019 9:54 pm
by ON5HB
Make sure you have the system grounded, even electrical ground is good.
Also, outside at the loop antenna, put a 100 KOhm to 1 MOhm resistor over the 2 poles of the antenna, it will discharge the static to ground....the electrical ground.
I assume you use coax.

If you don't use coax, then take both lines, connect 1 MOhm to them and connect them to grounding, that will remove the static.

Use real resistors and not the modern type ones. You need to old fashion types.