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rain problems..

Started by springbok, April 24, 2010, 05:59:00 AM

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springbok

anyone had problems when it rains heavily.. i am based in johannesburg and we have had unseasonal heavy rain for the last 15 hours. when i returned home last night i noticed a blank screen, no aircraft at all  unless they are directly overhead. i am only using the supplied antenna mounted on my tv antenna mast and my property is surrounded by large trees which i think may be acting as a "brick wall" when wet???

bratters

If I understand your post correctly, it sounds as if you put the supplied antenna outside where it presumably got caught in a deluge?

If that's the case look no further for the root of your problem. The supplied antenna is for inside use only and won't withstand an onslaught from the elements.

If I've misunderstood, we need to look elsewhere.

PS used to live in Benoni in what seems like another life. Fond memories :)

springbok

that's it, unfortunately there is nobody in SA who keeps the external antenna for 1090mhz and with the exchange rate it is restrictive to import one..interestingly the instruction manual that comes with radarbox says " the antenna is not an internal antenna". will have to wait for the rain to stop to see what happens, during the night the rain had stopped for a while and i started to get a few contacts, although there is not much traffic in the middle of the night... i think the problem could be the large trees around  my property which could be blocking the signal whilst the trees are wet , i had a similar problem a few years ago with my satellite dish a few years ago when it rained..

bratters

Hi again - from what you say I think the damage may be more serious. The fact that you can only see aircraft virtually overhaed suggests that the SAW filter in your box has been damaged. There has been chapter and verse about this on the forum with long discussions about cause - static from non-earthed external aerials etc. - but the supplied aerial being used outside is one of the prime suspects.

It's happened to me (a window ledge) and it's happened to others.

I'm surprised the (latest?) instructions say it's not an internal antenna - strange, because it is.

If the filter's blown you need to send the box back and get it replaced. The best course of action is to contact Airnav Support and explain what's going on and they will advise you what to do. They monitor the board anyway so will possibly already be aware.
Mention the "external use only instruction". Something radically wrong there..

Good luck.
John

springbok

will have to wait and see what happens once the rain stops and the trees dry out and hopefully it is not the box.....the aircraft overhead is the one area which is not got trees in the way and in the one direction towards lanseria airport is open and i get the Kulula aircraft on finals or departure before losing them as they pass behind the trees..

this is a cut and paste from the instruction manual...

QuoteAntenna Positioning
RadarBox comes with a small magnetic base antenna and this antenna has been selected for its
excellent performance when used with the hardware receiver and AirNav software. Correct positioning
of the antenna is essential in order to gain maximum performance as ADS-B signals are transmitted in
the 1090 MHz Ultra High Frequency band, which is eight times higher than VHF aircraft voice
communications. At this frequency, signals travel by "line of sight" and are affected by any
obstructions such as buildings, trees and hills. This means that if anything comes between you and
the aircraft, then that aircraft will probably not be displayed by RadarBox. In order to achieve
maximum performance and to ensure good range and coverage, the following points should be noted:
· The RadarBox antenna is not an internal antenna.
· The antenna should ideally be positioned outdoors and clear of obstructions.
· The higher the antenna, the better the performance.
· Performance is enhanced by a "ground-plane" which is simply a metal disk the size of a CD or
larger. Attach the magnetic antenna to the center of the disk
· The longer the feed cable, the poorer the performance.

tarbat

Current manual states:

Quote· The supplied RadarBox antenna is not intended to be mounted permanently outdoors.
· The antenna should ideally be positioned with a clear view of the sky and clear of obstructions.
· The higher the antenna, the better the performance.
· Performance is enhanced by a "ground-plane" which is simply a metal disk the size of a CD or
larger. Attach the magnetic antenna to the center of the disk
· The longer the feed cable, the poorer the performance.

springbok

interesting as i have only had my radarbox for 6 weeks so one would think the info is fairly up to date!!!!

tarbat

#7
Maybe old stock?  Are you running the 2010 version of the software?

Anyway, check the centre pin on the antenna cable, to make sure it's connecting okay to the Radarbox hardware.

springbok

yes using ver 3.13 and checked the pin which seems okay as is new cable and was working fine until the rain started yesterday, at the moment only getting overhead aircraft and finals /departure at lanseria airport which is not blocked by any trees but once they are airborne and disappear behind trees i lose the signal so until the rain stops i am leaning towards the wet trees blocking or reflecting the signal..

springbok

incidentally when i connect to the internet i get all the network traffic okay , not sure if that would happen if the box is faulty??

bratters

Two different sources unfortunately - aerial is MyFlights - network is internet.

springbok

okay, but you have to have the box connected to receive the network traffic?? i do not get any network traffic without the box connected..

tarbat

Quote from: springbok on April 24, 2010, 08:57:46 AM
okay, but you have to have the box connected to receive the network traffic?? i do not get any network traffic without the box connected..

Correct.  Best advise is to probably wait a few days and see how the system performs after the rain.  ModeS signals are line of sight, so I guess wet trees could block the signals.

If there is damage to the box, then if it's only 6 weeks old, return to the retailer you bought it from.

springbok

yep thanks , wait and see once the rain goes, i have spoken to the retailer who says if still a problem we can take it and connect to his set up and see what we get otherwise he will have to send it back for repair, thanks anyway

tarbat

Good advise on the "other" forum (where I'm banned from posting unfortunately).

junglejet said:
"Heavy rain generates static voltage on the antenna. We have lost a few miniADSB units in rain before the ESD protection was enhanced. Without a protective cover an ungrounded antenna should not be used outside."