AirNav Systems Forum
AirNav Radar => AirNav Radar Discussion => Topic started by: daveg4otu on May 16, 2009, 02:17:40 PM
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My ANRB - 3 weeks old , has already had to make one trip back to W&S for repair - died after just 4 days initially...returned, fixed , back to me a week ago - just died (very suddenly)again today .
(Told at time of repair about "Filters" & static - mods will be made etc.....)
When I say " died I mean - range gone from 150-200 miles to 20/30....activity at 10% of what it should be.
Spoke to W&S on phone just now - it's got to go back again on Monday.....
Setup is thus....Radar box in room-- antenna ( a magmount type MD1105) on Biscuit tin on flat roof of same room on a small(3 feet) stack of bricks(so maybe 12 feet AGL)...overall height about 400 amsl overlooking Lyme bay .
Weather at time of failure - showers/wind about 20-30 knots from SW .
My question is this ... is it static via the antenna causing this? - or is there a more deepseated cause (design flaw perhaps)?
I struggle to see how static is going to cause this - after all any antenna is exposed to wind/rain etc .....if static was going to do this - then I might expect my scanner, Digibox and any other radio rx/tx to suffer.
As a radio Ham I have had in the past all manner of antennas up in the sky - and other than pulling everything when there was lightning about for safety - I have never had to take any kind of extra precautions
I need to find a solution to this as I would like to have the thing in continuous use rather than it spending 50% of the time being fixed.
Any thoughts on this would be very welcome.
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Hi Dave,
Sorry to hear about your double problem. Mine is still in at W&S at the moment.
I am also a radio ham and agree with all you say.
If it had happened last night I could have understood it as we had terrific thunder and some lightening.
Your symptoms are exactly the same as mine. It died all of a sudden. At 14.00 it was perfect and at 15.00 gone.
Weather here was sunny, part cloud and dry.
I have the Radar extender antenna up on the chimney stack.
Hope you get it sorted soon. I hope I get mine back soon as well it is 10 days away now.
Regards
Terry
G0VTI
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Commiserations Terry - not that that helps....hope it comes back quickly.
To be fair to W&S I got mine back very quickly after the first return- and they did keep in touch - they phoned to say it had been dispatched etc.
If anything this time round it is probably worse than the previous episode showing right now only one contact ...and that is almost overhead!
Sad thing is that I was just saying to myself how well it was going - yesterday - I left it running from about 8 am to 11pm and it logged over 1500 flights.
Today up to the "death" it was at 980....since then (about 1400) only another 12.
Great piece of gear if it can be made to operate consistently.
73
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Hi Dave,
Firstly we very sorry to hear of the troubles you are having. The second failure might be due to the repair or another static spike. We cannot say untill our team looks at it. If its due to the repair thens that's unfortunate issue and hopefully it will be full rectified.
If its due to static again we recommend your antenna is ground or purchase an antenna with a grounded design or is built to limit static build up. Or purchase a mast amp, pre amp which should help bleed any static away from the RadarBox.
Windy conditions are actually perfect for static build up, cars, aircraft all pick up static in that way. This is not a design fault, if was there would be hundreds of customers here with the same issue. Yes it has been a concidence there has been a few at the same time, which could be related to weather. However cutomers need to be aware of the static risk in any antenna and to make sure you look for ones which limit static build up.
Terry:
I think you emailed as well regarding when your RB is coming back. As mentioned on here the return time is usually 5-10 working days.
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If wind = static - then running this thing in any mobile config would be problematical....and - as it happens it is a lot less windy today than it has been earlier (over w/end had gusts to 50 mph).
Guess I'll have to wait and see what the outcome is - but I do think it's a pity that this problem seems to occur .
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Just to add the Lightning monitor station on the IOW has "no storms detected" over the past few hours - only strikes are a few in mid France.
Had there been excessive levels of static - one might expect to see some T-storm activity in the UK mainland..
For those haven't seen it before....
http://www.isleofwightweather.co.uk/live_storm_data.htm
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Dave,
Lightning is the frst thing people think of when static electricity is mentioned. Lightning is an extreme occurance of this. Statis build up regardless occurs all the time.
We really advise any customer (infact anyone putting up an antenna) to understand the risk assiocated with static build up.
Have a quick read of:
http://www.keohi.com/keohihdtv/hdreception/antenna_grounding.html
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ANS ...yes I've read that - and dozens like it over the years.
This should be sortable without resorting to masthead preamps...and as I already have a range of over 200 miles(when working) that is an expense that I would consider as pointless.
I think the point that needs addressing - if static spikes are the problem - is- why are a few users having this problem - whilst apparently most are not?
Perhaps the box needs more robust internal protection if the problem keeps on occurring .
It would be interesting to know - how many are using Magmount type antennas outside - with unearthed ground planes?(A good number I would guess)
If so - any problems?
In addition I would like to hear any opinions on an efficient method of grounding a magmount ...my idea is to try by removing the protective rubber shield on the mount - so that the magnet makes direct electrical contact with the GP (in this case a biscuit tin lid ) and then ground the tin via an earth spike.
Or ..................?
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Hi Dave,
"I think the point that needs addressing - if static spikes are the problem - is- why are a few users having this problem - whilst apparently most are not?
Perhaps the box needs more robust internal protection if the problem keeps on occurring ."
Everyone setup is different, different antennas (some which are designed to limit static), different weather conditions etc..
Regarding changing anything, in the newer builds of RB we have increased protection against static (it was already there but we have increased it). Regardless even then if you subject any device to a large static voltage it will suffer damage.
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Hi
I have had my RB for close to a year now and never had a problem, I have used this mobile and I use a external antenna at home, the box get connected and disconnected to use mobile. Seems strange that a lot of people on here has had no problems and just a small amount has.
Cheers
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My ANRB - 3 weeks old , has already had to make one trip back to W&S for repair - died after just 4 days initially...returned, fixed , back to me a week ago - just died (very suddenly)again today .
(Told at time of repair about "Filters" & static - mods will be made etc.....)
When I say " died I mean - range gone from 150-200 miles to 20/30....activity at 10% of what it should be.
Spoke to W&S on phone just now - it's got to go back again on Monday.....
Setup is thus....Radar box in room-- antenna ( a magmount type MD1105) on Biscuit tin on flat roof of same room on a small(3 feet) stack of bricks(so maybe 12 feet AGL)...overall height about 400 amsl overlooking Lyme bay .
Weather at time of failure - showers/wind about 20-30 knots from SW .
My question is this ... is it static via the antenna causing this? - or is there a more deepseated cause (design flaw perhaps)?
I struggle to see how static is going to cause this - after all any antenna is exposed to wind/rain etc .....if static was going to do this - then I might expect my scanner, Digibox and any other radio rx/tx to suffer.
As a radio Ham I have had in the past all manner of antennas up in the sky - and other than pulling everything when there was lightning about for safety - I have never had to take any kind of extra precautions
I need to find a solution to this as I would like to have the thing in continuous use rather than it spending 50% of the time being fixed.
Any thoughts on this would be very welcome.
Thank you for sharing your sentiments with us but I really don't know if it is static via the antenna that causing this or is there a more deep seated cause?
_________________
Furnace Filter (http://www.iaqsource.com/furnace_filters.php)
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Dave
Would you keep us updated as to what goes on and any findings that come to light
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Yes - I will -.....
The box has gone back to W&S - it arrived with them yesterday so hopefully it will back here fairly quickly.
In the meantime I am in the process of adding an earth stake connected to the Antenna coax shield...see what happens with that.
Then if there are any further problems I guess it will mean making up one of Karl's little gizmos (see the thread about grounding antennas)...but hopefully that won't(shouldn't) be needed.
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daveg4otu
unlucky mate and sorry to hear about your RB going wonky again. I think you have great patience in your posts when asking questions ETC. I understand it's a fairly new product but some of the reponses beggers belief. I myself hav not had any problems with my unit as yet (1 month old) it does however stop working and I have to restart it from time to time. I for one am still waiting for an explantion as to how to ground the anntena i'm about to erect 20 foot above my chimney(sod the neighbours). Anywy here's hoping for a reply from some radio/ham expert.
Anyway daveg4otu if ET flys over in UFO1 i'll let you know. hope you get your RB back soon.......... p.s hundreds of members on here but only a few post...... so come on NONE POSTERS don't be shy
colin
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hi dave.got my rb back from w&s yesterday,second repair since easter,exibiting same symptoms both times,exactly the same as you.first time blown front end filter,second ,dry filter and usb joints had to be resoldered.the rb is working fine at the moment,am concerned about this static issue, and intend disconnecting external aerial at end of each session.
regards,davidh.
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Well - I heard late today that it is on it's way back - SAW filters fixed.
So- will see how it all goes.
The antenna ground side is now earthed via a connection from an earth stake outside the window to the coax shield.
DavidH - mine failed both times when in use - but disconnecting when not in use can do no harm as long as you don't overwork the rather fragilesocket on the RB.
Ted ...I've had antennas ranging from 40m dipoles down to 70cm rotatable yagis up (and down) for the past 30 years at various locations.
All I have ever done is earth the masts with a good heavy cable to an earth stake - purely as lightning protection.....when thunder threatens I disconnect all equipment from any antennas.
This is what puzzles me about the RB....this problem really should not happen
If you are really worried about potential problems then read the other thread (see my remark above about Karl's gizmo about 3 posts up ) contact Karl and I 'm sure he'll send you the info .
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Dave
Glad to hear the box is on its way back to you.
As you rightly say it should not be happening, but I don't think we have heard the last of it.
Fingers crossed you have no more problems.
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Well - firstly a bouquet to W & S for speedy turnaround - it arrived back here at 8.45 am today.
The service note inside said "SAW front end filter changed."
I put in on at 9.00 am...left it running while we took the dog to the beach....
Immediate noticable differences even when compared with it as it was when working "properly" previously.
In one hour it logged 430 flights(running hardware flights only)...but the most noticable diff is the number of flights on the board at any one time.
Previously - same time of day, a good count would be 60-70max.... now showing around the 100 mark all the time - never seen it up in that range before..as I look now it is showing 116!
EDIT(10.35BST) - now showing 129 - never even in my wildest.........!
I don't think the geographical range has changed(too many terrain limitations for that IMO) - rather that it is picking up and decoding more weaker signals
So - now the question - is the difference in performance because I have earthed the groupd plane side of the antenna ...or is it because the new SAW filter is performing better than the previous.... ?
Any technically minded readers care to offer an opinion? (I know what I think right now!
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Hi Dave, glad you're up and running again - just a theory, I think it's less windy, so the signals aren't getting blown away so much..................
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Dave
You have now got me thinking.
When I put my box on I am lucky if I get 20-25 in the log window, and on looking in the message it never goes any higher than about 45
As there is no definitive explanation of what to look for in relation to the problem
I am now wondering if it should go back to W&S?
The box is in the 600's range
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But what about the signals that are being blow towards the aerial?
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Additional info....
Watching the display carefully for a few minutes confirms that the overall polar diagram is unchanged with targets disappearing at exactly the same points as before...just the total number of recorded flights within that same polar diagram has increased by between 50% - 80%.
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Thanks Jon - I knew a technical explanation would be forthcoming fairly quickly!
:)
Malc where are you?- yes that is food for thought.
....I'm on the coast at Torquay facing NE with high ground behind me to the S & W(yes I know that sounds contradictory for the South Coast - but look for Babbacombe)...so my effective capture area is basically a semicircle between NE & SW(up to 200 miles) with minimal coverage out to the West and South (max about 30/40 miles)
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Dav
Just south of the Humber about 15 miles from EGNJ to the East
Get flow up the country and have 2 airways nearly right overhead
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Would have thought you should get good coverage right down towards the London TMA and out to the east over the N Sea(depending on you actual height etc)- but I guess the Pennines might block you to the west
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So - now the question - is the difference in performance because I have earthed the groupd plane side of the antenna ...or is it because the new SAW filter is performing better than the previous.... ?
earthingh won't do the difference , Dave. (Simply remove it for a while to prove) Anyway, it is one of the first measures to protect against the subject is about.
Kind Regards
Karl
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Yes exactly, only using the mag mount aerial outside bedroom window. Get good range to the west at altitude, loose EGCC bound flights at about FL100 so probably Pennines as you say. Get a southern coverage down to about TNT/GAM area.
But as I said before my message arte seems to be quite low?
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Yes Karl - exactly my thoughts.
Malc - message count here right now(94 flights on the board) is running around 200 to 280 per sec.
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Dave
oh well, from the look of it, it could well be on the way back to W&S
how did you get in touch with them, direct or via support?
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I phoned direct in the first case...second time round I initially vented my anger at the supplier(up in W Yorks)- the manager there contacted W&S first thing Mondayy -and by 3PM the box was on it's way to them.
I phoned W&S on Tues to confirm it had arrived ...the rest you know.
So - I'd say that probably your best bet is to phone direct....ask to speak to the service dept.
They are very helpful.
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malc41,
Wait a second before you send it back. The failure of the SAW filter makes itself apparent when your reception is very limited, i.e (down more than 80% of your usual coverage)
If you had always had low message count its not a RB issue its due to your location and the amount of signal you are getting. I would suggest taking your RB with a laptop to a hill nearby and then running it and seeing whether your reception is much better to put your mind rest.
Also to any customers do NOT send back your RB without contacting us first, as it will be a waste of our and your time and money if there was no issue.
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Thanks support
Will give it a try
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Just a quick update.....
At 1645BST the Aircraft count in "MyLOG" passed 1400.... previously I reached that total on one day but it took from 7am to midnight.... today that total took just under 8 hours!
Whatever was done it has made a a significant change in performace - or LATCC are having a very busy day.
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I have had the static range fault for around 3 months now, my range dropped from around 180 miles down to 25 miles. However as I still get around 1200 aircraft a day in that 25 mile range cone and with the configuration of the airports and airways near my house, I haven't lost a great amount of overall movements. I just see them on the box for a lessor amount of time. I still cover all my visual range.
I decided I would wait until Support got V2.1 out and sorted before I bothered them. Therefore I plan to send mine back sometime in July.
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AWC- looking at your location a bit of attenuation might be a blessing!
:)
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ME pictures dave with a dirty big grin on his boat race:)
Glad yer back up n running mate.......Colin
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At my age, being one of the ‘concessions’ (sounds better than Old Age Pensioner) :-) I don’t normally get involved in matters where my contribution may seem contentious and I hope this posting is not taken as a dig at AirNav. That is not my intention.
But he two linked threads:- “The Static and Filters problem etc” and “Radarbox Faulty” are not really getting very far by way of a positive explanation and solution to the problems a number of users are experiencing which would appear to be solely connected to the SAW filter fitted in the earlier RBs.
I feel that AirNav are being a little evasive and could perhaps comment on the points raised below.
Firstly, AirNav said in reply to my earlier posting that:- “It is not a design problem. The levels of returns are still very low for it to be considered an problem. We acted in a maner at the time these came to light to increase the protection in newer batches.”
It quite clearly is a design problem no matter what percentage of users have experienced failure. Otherwise there would be no need to change the spec in boxes manufactured after July 2008.
Would you expect, or do you not think it reasonable to assume more of the earliest boxes will sooner or later develop this fault?
From todays posting it would appear that the new spec filter significantly increased the number of flights daveg4otu logged from even before the filter ‘failed’.
Have you done tests with older and newer boxes running side by side? Could it be that users who have boxes in the earlier batch have less contacts than those with later ones and would never know unless the filter ‘went worse’ and their RBs had to be returned?? If so, shouldn’t all boxes made before the July 2008 ones be recalled and modified.
In his first posting, daveg4otu said:-
"My question is this ... is it static via the antenna causing this? - or is there a more deepseated cause (design flaw perhaps)?
I struggle to see how static is going to cause this - after all any antenna is exposed to wind/rain etc .....if static was going to do this - then I might expect my scanner, Digibox and any other radio rx/tx to suffer.
As a radio Ham I have had in the past all manner of antennas up in the sky - and other than pulling everything when there was lightning about for safety - I have never had to take any kind of extra precautions"
Sounds reasonable to me.
Is there an explanation as to why, if you are convinced there is no design problem, and that static is indeed the cause of the problem, why it only affects RadarBoxes and not the competitor’s units and why it affects them no matter whether the supplied antenna or an alternative is connected?
Regards
Syd
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To answer your questions:
1.) No, its small number as mentioned by development. We increased the design to limit static getting back into the filter further in the newer box. Considering many of these boxes have now been running for 2 years we do not see a rise in a return from this batch. Even so we have explained that any customers from this batch having an issue related to static damaging there SAW fiter after there warranty period, we will still fix it for free.
2.) No, Other customers who have returned RB for static damage have got it back with the same reception as before. I think atmospheric conditions and maybe a difference in antenna location has caused this. Also you know when you have SAW filter failure as the difference is massive from when its working properlly.
3.) Both devices are senstive, and more senstive than what you have mentioned due to specfic signal they are looking for. We also posted a link showing how static can affect any device.
As long as your antenna is of anti static design or grounded or has a preamp bleeding away any static you should be fine.
In total in both batches, were talking about percentage of customers less than 0.5% who have been affected.
Hope that helps. We are not hiding the details, its just spread out across many threads customer start. We will put this in the FAQ section soon.
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AirNav Support
May I make a couple of comments regarding you last post.....
In 2) you said....
I think atmospheric conditions and maybe a difference in antenna location has caused this
In fact the antenna is the same antenna in the same position as before...... and as UHF signals are essentially line-of-sight, weather is never going to be a major issue (barring extreme precipitation conditions).
The fact is that this box - one of the later batch as you know ...when first received would peak at about 60 aircraft in "My Flights"....this dropping to zero - 10 when the box first went wrong.
After the first repair ("fixed dry joints on filter and USB)" , performance was the same as original until the box died for the second time.
Now after the second repair ("Replaced SAW filter") ....there is a noticable upsurge in performance - overall at a guess it is receiving approx 50% more signals(within the same footprint) ....this is far more than can be explained by "atmospheric conditions".
Even now at close to 1900 local time (when previously I might have expected 40 or so flights) it is showing 84.
Please don't think I am complaining - in fact very much the opposite - I'm pleased as Punch....but remember , that like most new users,I had nothing to compare with when I first ever used the box.