Radarspotting
Miscellaneous => Other Topics => Antennas => Topic started by: north borneo radar on May 05, 2013, 02:01:34 PM
Hi all,
Just asking what type of lightning arrestor would be suitable for ADS-B antennae? I realize this is a grey area... but living in a tropical country where thunderstorms could happen quite frequently, I rather make sure my receiver is not damaged by static.
will something like this be ok?
http://www.thedxshop.com/inter-series-coaxial-adaptors/lightening-protector-0-2-5ghz.html
or
http://www.data-alliance.net/servlet/-strse-532/Lightning-Surge-Arrestor-Protector/Detail
quite a big differenc in price.
or any other suggestions/ideas?
thanks.
Oh oh this is a wide field for discussions and there is NO failsafe single solution
Forget the the term Lightning Protection, if one gets a hit thats it.
To answer your Q first, these inline devices are shunting the charges only.
Replaceable gasfilled diodes are ok but the minimum voltage before they fire
say the 90VDC may be to high for our low cost circuitry.
I cannot say which may be better for your need.
The difference in price may be because one is rated 1000 W Transmitting Power,
the other only 50W.
Generally Protection should start at lower voltage level.
Poor men's solution e.g. simple coax T-Connector with a 10K Ohm Resistor
permanently inline accepting a bit minor reception.
Another solution is a little gadget with a capacitor inline and a HF-Choke Coil
to coax-ground in a metal housing, thus shunting DC and passing HF only.
Sorry I have no spec Values. A local HAM club could be of help.
The next higher protecting levels require direct grounding to Earth Ground
of ample size in cross-section.
So far to static discharges or lightning induced charges.
Another question is whether to do even more ?
Depends on the location
Though we aim to place the antennae as high as possible
is this thin collinear a likely target with its thin unimportant coax ?
Or are other healthy and wet trees more attractive?
Often it is not reckoned that a downleading lightning is being met springing from earth up.
So questionable philosophy is whether to mount a full-size lightning discharge system
with catching rods, collecting lead, downlead, ground system buried deep,
all that of ample diameter and distance from structures.
Or leave it to the above 2 steps.
Life is threatened by death from birth on - and we live with it.
I always ask have you ever had a problem with a TV antenna or FM stereo antenna?
If the answer is no then why would your adsb receiver be any more exposed?
Something like this is fine http://www.diamondantenna.net/sp3000p.html and reasonably cost effective
Regards
Thanks for your input and advice, Truetrack and Chris.
Perhaps I will just opt for without using one then. cheers.
The BesTEST Lightning arrestor is the 1/4 wavelength shorting stub - if you can cut the short to the correct length.
http://www.volex.com/images/pdf/old/rf_qtrwavestub.pdf
http://www.hubersuhner.com/en/Products/Radio-Frequency/Lightning-Protectors