AirNav Systems Forum

AirNav Radar => AirNav Radar Discussion => Topic started by: springbok on April 24, 2010, 05:59:00 AM

Title: rain problems..
Post by: springbok on April 24, 2010, 05:59:00 AM
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???
Title: Re: rain problems..
Post by: bratters on April 24, 2010, 06:42:53 AM
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 :)
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 06:55:29 AM
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..
Title: Re: rain problems..
Post by: bratters on April 24, 2010, 07:32:33 AM
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
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 07:46:44 AM
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.
Title: Re: rain problems..
Post by: tarbat on April 24, 2010, 07:50:05 AM
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.
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 08:01:30 AM
interesting as i have only had my radarbox for 6 weeks so one would think the info is fairly up to date!!!!
Title: Re: rain problems..
Post by: tarbat on April 24, 2010, 08:10:30 AM
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.
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 08:33:29 AM
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..
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 08:49:47 AM
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??
Title: Re: rain problems..
Post by: bratters on April 24, 2010, 08:53:09 AM
Two different sources unfortunately - aerial is MyFlights - network is internet.
Title: Re: rain problems..
Post by: 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..
Title: Re: rain problems..
Post by: tarbat on April 24, 2010, 09:02:04 AM
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.
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 09:17:58 AM
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
Title: Re: rain problems..
Post by: tarbat on April 24, 2010, 09:32:54 AM
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."
Title: Re: rain problems..
Post by: bratters on April 24, 2010, 09:50:18 AM
Quote from: springbok on April 24, 2010, 09:17:58 AM
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

That's the right move. Hope it turns out OK.

BTW what's the problem with cost of an external aerial? Is it purely postage or do you have to pay some sort of import duty? We can ship to UK from the States at quite reasonable prices.
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 09:52:52 AM
for instance the radar rama antenna is 50 pounds which in Rand is nearly R600 and the cost of postage is around another 35 pounds so in rands it starts to get expensive, and to courier it costs around 125 pounds... my sister is visiting in the UK in july and the idea will be for her to bring it back which should be a cheaper option..
Title: Re: rain problems..
Post by: CoastGuardJon on April 24, 2010, 11:10:26 AM
Hi Springbok, I also used the standard supplied antenna outside and it only lasted a couple of months, when I took it apart, water/damp had penetrated the base, the copper wire hads corroded badly and disintegrated, chopping the doenlead into 6" sections, the damp penetration had gone right down to the SMA plug.   Resultant effect on the RB was exactly what you're experiencing, so I would suggest if the first instance to dis-assemble the antenna base, peel off the sticky back plastic, and prise out the magnet/screen, and have a look!

I've since dis-assembled another 2 standard antennas, soldered them up properly, pumped them full of electricians' silicone grease (NOT silicone sealant, which'll eat copper) and one of them, has now been outside for some 8 months, and is providing superb signals.

I did write up a post on how to weather-proof the standard antenna, and will find the link if you want it, but before worrying about the Box have a good a look inside the antenna base.
Title: Re: rain problems..
Post by: springbok on April 24, 2010, 03:57:41 PM
thanks will check that, i have brought the antenna down and still no great shakes, although i had rapped a plastic sandwich bag around the base to try to keep it dry and unfortunately it was all very wet... will have a look inside....
Title: Re: rain problems..
Post by: AirNav Support on April 24, 2010, 08:36:46 PM
springbok,

Sorry to hear of your issues. There was a mistake in earlier manuals and if your box is suffering from issues they will be no problem it getting it repaired by us. It will be covered under warranty.
Title: Re: rain problems..
Post by: Allocator on April 24, 2010, 08:41:02 PM
Quote from: bratters on April 24, 2010, 07:32:33 AM
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

This is what the V4.03 Help file says about the antenna:

· 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.

Title: Re: rain problems..
Post by: springbok on April 25, 2010, 07:22:34 AM
Quote from: AirNav Support on April 24, 2010, 08:36:46 PM
springbok,

Sorry to hear of your issues. There was a mistake in earlier manuals and if your box is suffering from issues they will be no problem it getting it repaired by us. It will be covered under warranty.
thanks, i will be returning to the local dealer on tuesday who will return it for the repair, unfortunately living in south africa it is a rather long distance to send it back for repair...also as a person just starting out with this hobby when you see in the manual ....This is not an internal antenna.... you take that as meaning that there is no problem with it being outside, anyway i have managed to find a company in SA which can make an external antenna for about half the cost of importing one so whilst the box is being fixed i can get that made up and installed..
Title: Re: rain problems..
Post by: Allocator on April 25, 2010, 08:02:04 AM
I must admit that I interpreted the manual guidance to say that you wouldn't get decent performance if you had the antenna on top of your PC in a basement flat - rather than 'You must mount this antenna outside 24 hours of the day'.

Mind you. I did use the standard antenna outside on a Velux window for 6 months without any issues.

I suppose in this day and age when you have to put messages like 'Don't set fire to yourself' on a box of matches, then it all becomes clear - lol
Title: Re: rain problems..
Post by: springbok on April 25, 2010, 10:25:03 AM
the manual i got with my box says


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.  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.


so to accept this and use it outside is understandable if the manufacturer says it is okay to do so...
Title: Re: rain problems..
Post by: orkney on April 25, 2010, 10:42:32 AM
Quote from: springbok on April 25, 2010, 10:25:03 AM
the manual i got with my box says


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.  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.


so to accept this and use it outside is understandable if the manufacturer says it is okay to do so...

hello

here is an extract from the manual we got. It advises against outdoor mounting

Andrew
Title: Re: rain problems..
Post by: Runway 31 on April 25, 2010, 11:00:54 AM
I think we have already established that there is an error in some manuals and that is why Airnav have stated the warranty will cover the repair.


Alan
Title: Re: rain problems..
Post by: springbok on May 20, 2010, 02:31:04 PM
finally got it back today and it was the saw filter that was the problem..