Radarbox faulty? low "my flights" count

[knight01]

In the last few days I have noticed a substantial reduction in "my flights" count and reception.  The antenna I'm using is in the loft.  I live only few miles from Heathrow.

With the loft antenna, before this problem started I was getting between 180 - 230 flights in "My fights".  But now I get below 110 flights at all times.  That's up to 50% reduction.  Right now its at 80, at around this time I used to get 190+.

I attached the supplied antenna again and I only get about 40 flights.  Again that's over 50% reduction.  Before with the supplied antenna, sitting on a windows sill, I was getting between 75 - 110 flights.

This just started happening from last week.  I've only had the radarbox since August and its was working fine (I was getting 180+ flights in "my flights") until last week. 
I didn't take notice at first, but it's getting worse on a daily basis.

I have contacted support, waiting for their reply.

Anyone know what could be wrong, while I wait for their reply.

[jannuh]

Hows the weather??  ;-)

Weather can have a negative influence, especially with an inside antenna.
Have you installed the SBS1 Lite meter, so you can really compare the myflights??

GL

[bratters]

Tropospheric conditions have been very poor lately; for well over a week in fact. Some days have been shown as "unstable" and, together with some curtains of rain, reception has been well down. No sign of an early improvement either.

After the excellent conditions that we enjoyed in september and october, it's back to earth with a bump. Either that or both of us have box problems - which I doubt.

Mind you it's still worth checking out connections etc just in case.
 

[palmar]

Thanks for the monthly met report. But there is almost no dependance of the 1090 reception on weather- except for ducting that enhances the range behind the horizon and is mostly associated with high pressure systems. 1090 is not tropospheric but line of sight. sic.

A degradation of reception as described indicates a faulty device or external interference.

But not weather.

Another option: change in Mode-S interrogation coverage, e.g. radar head maintenance. This would only affect flights that do not show position, though..

[Yellowshrek]

   Surely, for those in the northern hemisphere, it is because we are into the winter schedule, with all airlines operating fewer flights and so the numbers drop automatically. I suspect come the last weekend in March the numbers will then go up and we will see postings about the increase in numbers.

[tarbat]

Funnily enough, yesterday I had one of my highest aircraft counts, over 500.  I normally average 200-300.  Maybe all the aircraft are flying north for the winter!!

Seriously though, knight01, have you checked your polar diagram.  A faulty Radarbox normally has a very reduce range.  So, reset the polar diagram, and see what maximum range you're getting.

[Yellowshrek]

 Well there goes my theory. I have noticed more transatlantic flights heading north today, instead of coming across South Wales and the South West. 

  Tarbat, any significant difference in aircraft types and airlines in the increased numbers?

[jannuh]

With an antenna in the loft sure weather has impact on SHF,
even with an outside antenna!

A wet roof will reduce the signals received!!

[bratters]

Thanks for the monthly met report. But there is almost no dependance of the 1090 reception on weather- except for ducting that enhances the range behind the horizon and is mostly associated with high pressure systems. 1090 is not tropospheric but line of sight. sic.

A degradation of reception as described indicates a faulty device or external interference.

But not weather.

I bow to your superior knowledge.

All I can say is my own observations show that the distance at which signals are detected varies considerably on a daily basis, these signals being sent by known flights observed at similar times, at similar heights and on similar courses. Something must be responsible for this and others on the forum have pointed to this: http://www.dxinfocentre.com/tropo_eur.html

As for rain, I was under the impression that a curtain of water sufficient to totally block signals to my three satellite dishes would also reduce the range and quantity of flights shown on my RB. - anecdotal only.

[neroon79]

As a comment:

Every HF and especially the signal above 1GHz are very sensitive to the amount of water in the atmosphere. During periods of heavy rain and thick clouds the High Frequency signals where refracted and absorbed by the millions of the small water drops. But also different temperature layers -or to be more precisely the transition between them- can bow and diffract the HF signals. As a result the range and of course the number of received aircraft can decrease significantly in this "nice" November weather.

I got the best results last winter in the period of clear blue sky with constantly low temperatures across whole europe.

Let's hope for better weather conditions...

[jannuh]

Thanks for the monthly met report. But there is almost no dependance of the 1090 reception on weather- except for ducting//

Maybe Palmar is living in some nice always sunny place, lucky him

[knight01]

Thanks for all the info.  I got a reply back from support and they've asked me to send it to W&S.  This is what they have said:
"You can return to Hardware to the following address below and we will get a replacement to you once we have received it".

I'll try some of the suggestions before sending it.

[owensy]

FYI my count is a bit low today as well. In the past 10 mins I have had 4 a/c on and this is rather low even for a Saturday evening!

[Allocator]

It is a bit quiet tonight.

[palmar]

I got the best results last winter in the period of clear blue sky with constantly low temperatures across whole europe.

You are mixing things up here. This is called "ducting" and is a totally different phenomena during high pressure. The standard 1090 path is line of sight up to 180 NM around and it is not affected by low clouds. Very heavy rain storms maybe. You can't compare this to satellite reception. Lowest signals at the edge of line of sight range are maybe -95 or -100 dbm, while satellites are much below that (-130 and less).

And no, I am not living in a sunny spot, but usually low clouds and drizzle, and I have a constant 180 to 200 NM range (antenna inside the loft). Never had any change. But I own the other product.

As suggested, better use the rangeplotter to come to a precise assessment.