AirNav Systems Forum
AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: thenookorkney on March 08, 2022, 07:43:37 PM
-
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.
-
Here is one of my previous splats
-
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
-
.
.
.
What is the Maximum Range I can Get? (https://forum.radarbox24.com/index.php?topic=9251.msg139351#msg139351)
.
.
.
-
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.
-
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
-
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.
-
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
-
.
.
How-to Protect Outdoor Connectors and Cable From Ingress of Moisture (Due to Rain & Snow) and Resulting Short circuit, Corrosion, and Drop in Performance. (https://forum.radarbox24.com/index.php?topic=9131.msg517201#msg517201)
.
.
-
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.
-
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
-
Thanks
I got an auto response followed by a blank email from Alex, I did let them know but nothing further back.
Thanks
-
Contact him again
PM me your email address and i will get him to contact you
Alan
-
See this for home made antennas https://forum.radarbox24.com/index.php?topic=9131.msg134111#msg134111
Alan
-
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
-
I have a radar box and a flightstick, can do a bit of experimenting.
Thank you for that, its frustrating
Kindest regards
Neil
-
Your Fightstick Amplifier might have failed, Have you got another ads-b Reciever
Good catch Graham. Stick degeneration and Power Supply degeneration ( DC voltage provided by USB port to stick lower than minimum required) can cause all sorts of issues.
Are you using RB Windows software and the stick is plugged into Windows computer
OR
You are using Raspberry Pi with stick plugged into Raspberry Pi
If you are using Raspberry Pi, then you can check DC voltage issues by following command (no output of command means no issues)
sudo dmesg --ctime | grep voltage
.
-
Makes sense to me, I swapped about devices with no visible difference so I am going to connect to a different PC.
I tried yesterday but could not get the 360 radar software to work properly. Once I get that glitch sorted will watch with interest.
Thank you all
-
Given that there is no difference between two receivers would lead me to belive that the antenna or the cabling could be the issue
Alan
-
Given that there is no difference between two receivers would lead me to belive that the antenna or the cabling could be the issue
Alan
You are right Alan. After clearing the stick, antenna & coax cable are now prime suspect.
There is one more suspect: RF noise.
A strong RF noise will overload the stick's front end and will make it deaf to the weak signals from distant aircraft, causing reduction in range. The source of RF noise can be either some electrical or electronic appliance within the house, or some RF transmitting antenna outside, but near the house.
@thenookorkney:
Do you remember adding some appliance to your household at the time when your range dropped? HDMI cable are particularly good in radiating RF noise. Also do you remember if any TV or FM or Mobile/Cell phone antenna / tower erected near your house at the time when your range reduced suddenly?
.
-
Well, what do you know. As if by magic, I have gained 140 miles today. Numerous aircraft. Barometer is not particularly high, weather is awful.
Who would know:)
-
One reason what you are better off not worrying about it. You got a good couple of spikes out to the west over the sea beyond your normal coverage which will disappear in a week
Alan
-
100% the antenna, bought a new one and hey presto. Did not buy the Airnav one this time but great results.
-
Glad you got it sorted
Alan
-
Thank you for all the feedback, I have hired a cherry picker and going up to check it today.
My 200 miles is back with the new antenna which I bought from Pi Hut
Such a pity the real McCoy from Airnav lasted less than a year but I didnt realise it was failing until too late.
Here is this mornings feed