Messages

1

General Discussion / Re: Barometric Pressure Way-off ?

« on: December 19, 2016, 08:19:02 pm »

Why do I always seem to be doing maintenance work on my aircraft in the middle of winter?!

So it won't eat into summer flying time But it is a pain if the hangar/shed is cold and dark

Got it in one!

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General Discussion / Re: Barometric Pressure Way-off ?

« on: December 19, 2016, 06:06:03 pm »

Not yet, Keith. It's in my to-do list over the next few weeks, together with changing out my transponder for one that squitters appropriately. Why do I always seem to be doing maintenance work on my aircraft in the middle of winter?!

I'd be interested to know where you put the various antennas. I was thinking that the front of the engine bay might be a good place for the PAW antenna. I'd like to avoid taping it to the hatch if possible. The GPS and ADS-B antennas are rather less critical of course. I was thinking of running all the cables back to behind the seats, via the tubes under the central console and then putting the hardware there, out of the way. What did you do? If you'd prefer to take this to PM then that's fine.

3

General Discussion / Re: Barometric Pressure Way-off ?

« on: December 18, 2016, 08:50:46 pm »

Thanks Peter. Having finally got the track data onto my memory stick I've been playing around with the data and have discovered that it was one G-CCEJ, presumably of this parish, who buzzed the place at around 14:30 today, getting within a few hundred metres, so I think he must have seen the PAW alert and gone looking for the source! He would have found a white cottage on top of a hill with some VERY big aerials, none of which are anything to do with PAW. I think the RAF has it programmed in as a VRP.

I'm cracking this slowly...!

EDIT: I see that G-CCEJ is indeed in the PAW map and I have just added myself back there after my hiatus.

4

Technical Support / Re: Downloading track log file

« on: December 18, 2016, 07:20:23 pm »

It took me some time to discover that the USB memory stick must be formatted as FAT32. NTFS it does not like!

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General Discussion / Re: Barometric Pressure Way-off ?

« on: December 18, 2016, 06:18:40 pm »

Yes, I thought about that. I need to RTFM to find out how all that works. I guess I needed to enable some of the Log Interface Messages options in config but I hadn't done that, as most are too cryptic for me to immediately grasp what they do. The settings don't seem to save either. I'd better go and look out that manual... there's only so much one can discover by doing the blokey thing of not reading it.

6

General Discussion / Re: Barometric Pressure Way-off ?

« on: December 18, 2016, 03:01:51 pm »

Ahha, broken my duck! Something with PAW flew past a while ago and I picked up 79 P3I transmissions. Wonder who it was?

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General Discussion / Re: Barometric Pressure Way-off ?

« on: December 18, 2016, 11:14:16 am »

Hi Peter,

I've flown past East Fortune numerous times, en-route Fife/Perth/Dundee/other places north, but never actually landed there. I should do that some time!

8

General Discussion / Re: Barometric Pressure Way-off ?

« on: December 18, 2016, 10:40:10 am »

My PAW has now been on for ten days just sitting at home watching the world fly by. Interestingly, the pressure sensor is slowly drifting into spec - it's now just about 1mb out, which is insignificant for the intended application.

Still yet to receive a single P3i transmission but PAW is thin on the ground as yet, up here in the frozen north.

9

General Discussion / Re: Feedback: PAW pressure and Mode C/S

« on: December 18, 2016, 10:32:42 am »

Perhaps the label should be 'GPS calc QNH' to at least remind people that it is a synthetic value.

Yes, I think this makes a lot of sense. Even with DGPS the GPS derived altitude wanders around too much to give a reliable QNH accurate to the nearest mb.

10

General Discussion / Re: Barometric Pressure Way-off ?

« on: December 15, 2016, 01:55:34 pm »

Superficially it does look like the same barometric sensor and I note that the specified accuracy is circa 1ft, so this one being around 70ft out is something of a surprise.

11

General Discussion / Re: Barometric Pressure Way-off ?

« on: December 14, 2016, 05:34:33 pm »

I'm just getting back into PAW after a rather lengthy hiatus. I have the new bridge and it's working as far as I can tell (after six days not a single P3i transmission received, despite an external antenna out in the clear, but then I am in the far north!).

I am lucky to know my exact altitude (705ft) and I also have a calibrated barometer that is corrected to QNH on site. The GPS reported GNSS altitude does, of course, vary but it is typically within 20ft of actual (less than 1mb error). Correcting for that as necessary, PAW is consistently reporting my calculated QNH as around 2.5mb higher than actual, i.e. around 70ft out. This seems to be a barometer reporting error.

I realise that 70ft is nothing to worry about in practice but I just wonder what sort of nominal accuracy I should be expecting from the bridge barometer? The barometers on the old Harkwood ARF boards, which I still have, were both accurate to significantly better than 1mb.

12

General Discussion / Re: Does PAW work on RP3?

« on: May 11, 2016, 04:47:01 pm »

Just bringing this thread back to life because it seems that the RPi 2 model B+ is being overtaken by the RPi 3 model B (the model numbering convention is bizarre!). It seems that RS, Rapid, et al, are winding down stocks of the 2B although I suppose they will be available for some time yet.

Now that the full functionality version of PAW has migrated to the RPi 2, does (will) it also work on the 3? I am loathe to buy obsolescent kit but I do realise that it's a pain keeping the software compatible with all these new hardware releases.

13

General Discussion / Re: Not sure I have been sent extension Licence for ARF Replacement Purchase.

« on: May 11, 2016, 02:54:37 pm »

Thanks for the quick reply Dave. Wilco.

14

General Discussion / Re: Not sure I have been sent extension Licence for ARF Replacement Purchase.

« on: May 11, 2016, 02:25:43 pm »

Thanks Lee. I've been away from all this for a bit but looking forward to getting back into it.

Another question: in returning the old ARF modules, do we need to remove them from the carrier board (in my case the Harkwood PCB)? It may be a bit of a challenge to unsolder! The return documentation also implies that we should retain the ARF antenna (i.e. the new board does not come with its own antenna). Is that correct?

15

General Discussion / Re: Not sure I have been sent extension Licence for ARF Replacement Purchase.

« on: May 11, 2016, 11:23:38 am »

Not just you - I haven't either and I have a couple of quite old licence keys. Perhaps they are yet to go out to everyone?