AirNav Systems Forum

AirNav Radar => AirNav Radar Discussion => Topic started by: oubliettehoggle on September 20, 2009, 03:21:00 PM

Title: Loss of range.
Post by: oubliettehoggle on September 20, 2009, 03:21:00 PM
About a month ago I set my system up in the loft and had a range I was happy with.  I do live in quite a hilly area so expected some blind spots. My Radabox would pick up planes very well to the north of me and it fell off to the east west and south but was good enough for me to to have plenty of notice to actually spot the planes if it wasn't cloudy.

Now for the last three days, I haven't changed anything with the setup but I am getting hardly any range. When I check the Range Polar Diagram this has decreased significently to what it was.

I get a thin sliver of range to the north of me that extends about 5 miles, nothing in any other direction. So now I am picking hardly anything up at all in My Flights. Now I am luck to track one plane.

I can't think of anything different I have done, all the equipment is in the same place. The RadarBox shows little activity. Is this a hardware fault or could there be another reason.

Thanks
Title: Re: Loss of range.
Post by: Allocator on September 20, 2009, 03:26:04 PM
You don't say how you have set up you RB in the loft.  Is your PC up there too, or do you have a cable between your RB and your PC?  Where is your antenna, is it the standard antenna or have you got an external antenna?
Title: Re: Loss of range.
Post by: oubliettehoggle on September 20, 2009, 03:35:32 PM
The antenna is the standard one that came with the system. The RB is connected to my Laptop in the loft. I am only using what came with the system, I have added nothing new. That's why I can't understand why there has been a decrease in range when I haven't changed any of the setup or layout.
Title: Re: Loss of range.
Post by: Storm on September 20, 2009, 03:38:07 PM
Check all cables are secure and check that little pin that's inside the cable from the antenna to the box sometimes it gets pushed back in. Carefully and slowly try to pull it out with a pair of tweezers or something like that and connect it again.
Title: Re: Loss of range.
Post by: Allocator on September 20, 2009, 03:41:58 PM
I would turn off the laptop, disconnect the antenna and the USB lead from the RadarBox and reconnect everything to make sure that you have good connections.

Make sure that you plug the USB lead back into the same USB port on the laptop, otherwise you will have to install the drivers again.

Are the aircraft showing in MyFlights, but not on the map, or are they not showing on either?

Have you tried clicking the 'Show All' button on the RB toolbar?

What light indications are you getting on your RadarBox hardware?
Title: Re: Loss of range.
Post by: oubliettehoggle on September 20, 2009, 06:10:13 PM
Quote from: Storm on September 20, 2009, 03:38:07 PM
Check all cables are secure and check that little pin that's inside the cable from the antenna to the box sometimes it gets pushed back in. Carefully and slowly try to pull it out with a hair clipper or something like that and connect it again.

I did this and it seems to have made things a lot better.

Thanks
Title: Re: Loss of range.
Post by: oubliettehoggle on September 20, 2009, 06:16:32 PM
Quote from: Allocator on September 20, 2009, 03:41:58 PM
I would turn off the laptop, disconnect the antenna and the USB lead from the RadarBox and reconnect everything to make sure that you have good connections.

Make sure that you plug the USB lead back into the same USB port on the laptop, otherwise you will have to install the drivers again.

Are the aircraft showing in MyFlights, but not on the map, or are they not showing on either?

Have you tried clicking the 'Show All' button on the RB toolbar?

What light indications are you getting on your RadarBox hardware?

As from message to Storm when I pulled the pin out the range improved though I don't think it was as good as it has been, though I will see if range improves.

I did click "Show All" button but no improvement.

The lights on the RB are flickering rapidly, both the USB and Signal.

The only thing I would say though is that a lot of flights are appearing on "My Flights" but only a few appear on the map, is there anything I can do to improve this?
Title: Re: Loss of range.
Post by: Fenris on September 20, 2009, 09:16:25 PM
Quote from: oubliettehoggle on September 20, 2009, 06:16:32 PM
The only thing I would say though is that a lot of flights are appearing on "My Flights" but only a few appear on the map, is there anything I can do to improve this?

Can you describe which aircraft types tend to not show a position? Some aircraft do not have ADS-B capable avionics, so they don't encode their position. If you give us some idea we can pass comment on whether this is what is happening or whether there is something else preventing it from working.
Title: Re: Loss of range.
Post by: oubliettehoggle on September 20, 2009, 09:22:51 PM
Quote from: Fenris on September 20, 2009, 09:16:25 PM
Quote from: oubliettehoggle on September 20, 2009, 06:16:32 PM
The only thing I would say though is that a lot of flights are appearing on "My Flights" but only a few appear on the map, is there anything I can do to improve this?

I will report back next time I log in. Thank you everyone so far for advice given.
Can you describe which aircraft types tend to not show a position? Some aircraft do not have ADS-B capable avionics, so they don't encode their position. If you give us some idea we can pass comment on whether this is what is happening or whether there is something else preventing it from working.
Title: Re: Loss of range.
Post by: oubliettehoggle on September 20, 2009, 09:24:38 PM
Quote from: Fenris on September 20, 2009, 09:16:25 PM
Quote from: oubliettehoggle on September 20, 2009, 06:16:32 PM
The only thing I would say though is that a lot of flights are appearing on "My Flights" but only a few appear on the map, is there anything I can do to improve this?

Can you describe which aircraft types tend to not show a position? Some aircraft do not have ADS-B capable avionics, so they don't encode their position. If you give us some idea we can pass comment on whether this is what is happening or whether there is something else preventing it from working.

Sorry I posted my message within quotes......I'm not normally this bad, honest.
I will report back next time I log in. Thank you everyone so far for advice given.
Title: Re: Loss of range.
Post by: AirNav Support on September 20, 2009, 10:13:35 PM
If you have ruled out any other issues contact us via the methods in our signature and we can arrange a return and take a look at the box.
Title: Re: Loss of range.
Post by: prosinger on September 21, 2009, 03:34:26 AM
I just had to take the board out of my radarbox and re-solder the center pin on the antenna socket to the board. I'm fortunate to have a 70' radio mast on which I affixed my radar box external antenna and out of 6/7 aircraft I see in the sky at any one time, I'm lucky to pick one of them out on my radar box. I normally have a range of about 25 miles max and this seems to be to the north, when I know I have excellent take off on 2 mtr ham band to the south. I suggest you gently wiggle the antenna plug at the back and see if it makes a difference to the signal light flash rate.

Quote from: oubliettehoggle on September 20, 2009, 03:21:00 PM
About a month ago I set my system up in the loft and had a range I was happy with.  I do live in quite a hilly area so expected some blind spots. My Radabox would pick up planes very well to the north of me and it fell off to the east west and south but was good enough for me to to have plenty of notice to actually spot the planes if it wasn't cloudy.

Now for the last three days, I haven't changed anything with the setup but I am getting hardly any range. When I check the Range Polar Diagram this has decreased significently to what it was.

I get a thin sliver of range to the north of me that extends about 5 miles, nothing in any other direction. So now I am picking hardly anything up at all in My Flights. Now I am luck to track one plane.

I can't think of anything different I have done, all the equipment is in the same place. The RadarBox shows little activity. Is this a hardware fault or could there be another reason.

Thanks
Title: Re: Loss of range.
Post by: GlynH on September 21, 2009, 09:25:43 AM
Quote from: prosinger on September 21, 2009, 03:34:26 AM
I just had to take the board out of my radarbox and re-solder the center pin on the antenna socket to the board. I'm fortunate to have a 70' radio mast on which I affixed my radar box external antenna and out of 6/7 aircraft I see in the sky at any one time, I'm lucky to pick one of them out on my radar box. I normally have a range of about 25 miles max and this seems to be to the north, when I know I have excellent take off on 2 mtr ham band to the south. I suggest you gently wiggle the antenna plug at the back and see if it makes a difference to the signal light flash rate.

Quick question prosinger,

What coaxial cable are you using to connect your RB to the antenna?

Bearing in mind if that is 70' up a tower and you may still have some distance between the foot of the tower and your RB it is possible that loss may play a significant part in your RB not seeing what you are - unless you are referring to the problem pre-repair of course?

A quick rule of thumb regarding loss can be seen at the bottom of this page here; http://www.ssejim.co.uk/26-sseads1090sj.htm

Bear in mind that the figures quoted rarely take into account plugs/connectors and sometimes is more applicable to transmit rather than receive so is usually best-case scenario.

Obviously you know all of this already as you sound like a radio amateur to me (70' tower, mention of 2m etc)...but for anyone else reading this thread it might offer them a bit of help!

My 1090MHz antenna is mounted on a 17' pole on the top of the house and I have excellent coverage including most everything that I can pick up with the MKI eyeball...and many hundreds more that it can't :-)

Kind regards,
-=Glyn=-
Title: Re: Loss of range.
Post by: prosinger on September 21, 2009, 10:41:11 AM
Thanks for the reply Glyn, I'm using RG223/U 50 ohm coaxial cable, a very good quality but I'm sure not the best. It's attenuation for a 10mtr length is 4.7db at 1000 mHz. I brobably have around 18mtr in total, I only use good quality silver plated connectors but finish off with a bnc to (can't remember what the RB connector is called). Call sign G4NMP.

Brian
Title: Re: Loss of range.
Post by: Jeremy on September 21, 2009, 11:23:50 AM
Prosinger - The loss you are experiencing is more than just feeder loss. Anyway you say that it used to function OK. It must be either hardware connector failure or front end damage to the RB. I see 60m radius from the issued whip/magmount at 10ft surrounded by trees on a mediocre site.
Try a continunity test across the aerial plug. It is not certain but it is likely your aerial is a stacked verticle dipole array or stacked collinears so the feeder should not show a short (but this could be wrong).
If you have a 2m antenna then try using that. A detuned, off band antenna in the clear will give you more signal than a shorted connector or a blown fron end.
If 2M coverage is good to the south then so should 1 Ghz.
Jeremy G4DOQ
Title: Re: Loss of range.
Post by: Jeremy on September 21, 2009, 11:26:54 AM
Prosinger - If the aerial is a series of stacked folded dipoles the aerial continunity will of course show a short so this is not much of a test. However, if it shows open circuit then that may give you some confidence that it is probably not the aerial or connector.
J.
Title: Re: Loss of range.
Post by: oubliettehoggle on September 25, 2009, 03:53:06 PM
Quote from: Fenris on September 20, 2009, 09:16:25 PM
Quote from: oubliettehoggle on September 20, 2009, 06:16:32 PM
The only thing I would say though is that a lot of flights are appearing on "My Flights" but only a few appear on the map, is there anything I can do to improve this?

Can you describe which aircraft types tend to not show a position? Some aircraft do not have ADS-B capable avionics, so they don't encode their position. If you give us some idea we can pass comment on whether this is what is happening or whether there is something else preventing it from working.

I cannot seem to pick up DH8D aircraft (as an example) on the map but OK on My Flights, now some of these are Flybe so I am assuming these are not equipped. A typical display on My Flights may show 15-18 aircraft but only 1 or 2 on the map. The map does change so I was wondering if this is picking planes up on the edges or just beyond the Range Polar and as they fly into range they appear. Or should most of the aircraft show on My Flights appear on the map. Would I expect a certain ratio from log to map to show.
Title: Re: Loss of range.
Post by: RodBearden on September 25, 2009, 04:09:41 PM
Hi oubliettehoggle

If there is a blue globe on the left of the flight status column in MyFlights, then the aircraft is equipped with ADS-B, and should be appearing on the map. Unfortunately no FlyBE aircraft have ADS-B, even the new Embraers, so they don't appear.

Almost all modern larger airliners will have ADS-B, such as Boeing 737-800s and 777's but older types such as Boeing 737-300s and older Boeing 767s won't have.

You may also find that aircraft on the edge of your polar diagram may not show position until they move closer to you, because at extreme range your aerial may not correctly pick up the position signals from the aircraft, but may be picking up other data.

Hope that helps

Rod
Title: Re: Loss of range.
Post by: prosinger on April 08, 2010, 03:24:06 AM
I had a similar thing happen to me but found when I just touched the antenna connection on the back of the box, it went crazy with flashes. If you are using any kind of antenna adaptor be sure there is no strain on the socket on the back of the box. I replaced the original antenna socket with a BNC socket and I've never seen my airnav work so good, my range now is around 80 miles using an outdoor antenna at about 25 feet in quite a hilly area.

Brian
Quote from: oubliettehoggle on September 20, 2009, 03:21:00 PM
About a month ago I set my system up in the loft and had a range I was happy with.  I do live in quite a hilly area so expected some blind spots. My Radabox would pick up planes very well to the north of me and it fell off to the east west and south but was good enough for me to to have plenty of notice to actually spot the planes if it wasn't cloudy.

Now for the last three days, I haven't changed anything with the setup but I am getting hardly any range. When I check the Range Polar Diagram this has decreased significently to what it was.

I get a thin sliver of range to the north of me that extends about 5 miles, nothing in any other direction. So now I am picking hardly anything up at all in My Flights. Now I am luck to track one plane.

I can't think of anything different I have done, all the equipment is in the same place. The RadarBox shows little activity. Is this a hardware fault or could there be another reason.

Thanks