Have lost 200 miles on my setup

[thenookorkney]

Hello All

I have a standard set up, Flight stick with Radarbox external aerial.  For the last year my splat has been enormous catching aircraft down to Newcastle, across to Denmark and about 300 miles into the Atlantic.

About 2 weeks ago and without warning it dropped to 150 miles and usually less, struggling to reach Morayshire, Inverness-shire and only about half way to Norway.

My info on Radarbox.com showed receiving information about 90% of the time, now there are greater patches of no data than anything else.

I did try support but they do not answer for some reason.

Grateful for any suggestions.

[thenookorkney]

Here is one of my previous splats

[Runway 31]

You will note your previous splats were mostly in a mass with several spikes outwith your normal coverage which gave you the seemingly massive range.  The normal maximum range expected is around 250 miles.  I would expect that the reception of the aircraft signal was due to some freak of nature for example tropospheric propogation (https://en.wikipedia.org/wiki/Tropospheric_propagation) which sees signals going a lot further than normal.  The coverage areas are compiled over a week or so and the new coverage area did not have the freak spikes hence the normal coverage shown

Alan

[abcd567]

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What is the Maximum Range I can Get?

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[thenookorkney]

Thank you for the feedback.  To give you an idea, the little aerial gave me 100 miles easily as I am at 200 ft with a clear line of sight East, West and South.  The new aerial was installed at 18ft, above my roofline and the spikes to the North were higher aircraft.
I have been 250 miles + for over a year, the drop has been in the last 2 weeks so I can only conclude that something technical has changed.

I would not buy a proper external aerial and mount it in a higher position to get less distance than the small aerial that comes with a radarbox.  I work at an airport and everyday I could see what was taking off from Aberdeen, Edinburgh and Inverness within minutes of take off, which I cannot now. 

Its not my imagination that something has changed.  Can the aerial short in inclement weather and reduce its effectiveness.

[Runway 31]

Yes, water can get into the antenna and even into the cable,  However the range decrease would usually be really dramatic down to very shorts range

Weather can make a difference, high pressure gives greater range.  250nm is the usual max although on a good day you may get 20 miles or so greater.

The Maximum Range achievable at any location depends on

(1) Curvature of earth
(2) The terrain around that location. Terrain plays a very important role as hills & changes in ground level will restrict maximum range.

This is due to the fact that propagation of radio waves in GHz/Microwave range is line of sight. The range is therefore limited by curvature of earth, and is about 250 nautical miles / 450 km for an ideal condition of perfectly level terrain. Hills & rise in ground levels further restrict maximum range to less than 250 nautical miles / 450 km.

The layers of air mentioned in my last reply cause refraction of radio waves, and radio line of sight may extend beyond optical line of sight by as much as 50 to 100 nautical miles. Your maximum possible range will therefore be about 50 to 100 nautical miles more but that will depend on weather and can change day to day

Alan

[thenookorkney]

Here is the diagram from Heywhatsthat at 10000 and 45000 ft.

This is roughly what I have had for the last year, or close to.

[Runway 31]

That is the maximum thoretical and also remember that not much traffic uses FL450, FL350 would be more approriate.  From Orkney to Carlisle/Newcastle is approx 430 miles.  Also forget about the spikes in your previous coverage maps as they are freaks.  Take them away and what you are getting now closely resembles that.

If you  are not convinced I suggest that you change your antenna, what make is it.  Have you checked it and all the connections to ensure that they are tight and water tight.  Check that water has not entered the cable and the antenna althought reception would be much reduced if that was the case.  Any joints outside should be secured with amalgamating tape to keep them water tight

What is keeping your coverage to the north down?

Also you stated you contacted support, did you get an auto response, if not they have not received your email

Alan

[abcd567]

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How-to Protect Outdoor Connectors and Cable From Ingress of Moisture (Due to Rain & Snow) and Resulting Short circuit, Corrosion, and Drop in Performance.

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[thenookorkney]

Thank you

The aerial is airnavs own outdoor antenna which has a sealed cable at the base.  Where it goes through the wall the cable is angled up the way from the outside so there can be no water ingress.  It comes ready to connect.

The limit to the North is due to a hill I am situated on.  Roughly 500 ft higher than my house so I only pick up things which are high.

I am going to look up plans to make my own as I know a lot of people do.   I may have a look in the loft just to ensure furry friends have not snuck in over the winter.

Thanks for all your feedback.  I think a different antenna is the key.

Support is usually very good when I have questions but no response to this one even though asked more than once.

[Runway 31]

Did you get an auto response as if not they have not received your contact.  i doubt that they will be able to give any different advice

Alan

[thenookorkney]

Thanks

I got an auto response followed by a blank email from Alex, I did let them know but nothing further back.

Thanks

[Runway 31]

Contact him again

PM me your email address and i will get him to contact you

Alan

[Runway 31]

See this for home made antennas https://forum.radarbox24.com/index.php?topic=9131.msg134111#msg134111

Alan

[anchorage 53]

 Your Fightstick Amplifier might have failed, Have you got another ads-b Reciever
 you could try. The airnav antennas are well made as i have tested one  with good
 results.

                                 Graham