Navigator 2 in SIRF Mode

[Dave]

The 9532 is pretty much identical to a 9531, major differences are the new SiRF II support and also acquisition time, so I wouldn't have thought it would be more sensative then a 9531, but it could be the cable isn't shielded as well, or perhaps the receiver isn't as shielded as the 9531.



I remember back in the CB days when I used to have a 100w burner (amplifier) under the drivers seat, everytime I keyed the mic to talk, the indicators on my Ford Fiesta would either sound as though the indicators are blinking (tick tock), or it would make a fast short circuit type sound. There's a lot in-car that could interfere, it might be better off if you can locate it the passenger side of the dash with a modem extension cable and possibly a power extension cable.

[RichDem]

Hi Dave,



I am fairly happy that the receiver is not at fault I guess it is one of those things I will just learn to live with. Other than that the 9532 is an excellent receiver, it certainly locks on very quickly and since I upgraded the gps driver to 2.02 I now see a much stronger signal.



Hopefully in the future we will be able to use Navigator with a receiver running in SIRF.



Richard

[Dave]

It really could be 101 different things that could be causing this problem. Satellites do move across the sky, and I tend to find I see less satellites in the morning (pre 10am) than say at 6pm or even 8pm where I'll sometimes see nearly double.



I can also be localised interference, or problems getting a view of the sky or interference in-car. The best way to trouble shoot this is to make sure you're not near any buildings, park up in a layby or somewhere you can run tests, stay still for a few mins and watch the satellites fluctuate. You can also do this test when driving if you're only driving to work then it's a perfect chance to test this out. You'll probably see the sats fluctuate quite a lot. It could be a reduced signal in-car, due to in-car interference or bad shielding on the cables. I'm running a 9532 (in 9531 casing) and don't see any difference, but there maybe less shielding in the new 9532 mouse.



A rule of thumb I find is that in the morning travelling through cities in the south I'll see anything from 3-5 sats, if I'm lucky I'll get a 6 or 7 peak. On the drive home in the evening I'll see an average of around 7-9 sats, peaking at 11. Remember that TTN2 will require 4 sats for a 3D fix otherwise it will lose where you are, so if you're fluctuating around 3-5 and it keeps dropping to 3 sats then you will lose a fix. The other thing that really does help in diagnosing problems like this is an extra Pocket PC and GPS Receiver, many a times I've thought there's a problem in the sky, when I've found it to be the receiver that's glitched and sometimes thrown itself back to a factory reset.

[RichDem]

****UPDATE******



Hi All,



I thought I would post an update to my original message. I had to travel to Germany on Sunday for a 2 day course, this involved driving to my office where I had been going to all last week when I was experiencing the periodic loss of signal. I left at 10.30 am and had an average of 10 Sat's locked with no dropouts. I even had 12 Sat's showing on numerous occaisons whilst on the M4.



Travelling home at 9PM last night again had good average number of sat's locked with no loss.



This morning I left home at 6.30 am to travel to Peterborough. I had one instance where the signal dropped but other than that I had perfect reception all the way. Maybe I am clutching at straws here but it must be something to do with either the position of the sattelites, weather or maybe a change in the upper atmosphere early in the morning, it would seem that once you go past say 9am the problem is no where near as frequent, if it happens at all.



If there is anyone reading this post who maybe can explain why these anomolies seem to happen in the early hours of the morning I would be interested in hearing from them.



I guess as well that maybe the 9532 receiver is more sensitive than the old 9531 which does not seem to suffer from this problem.



Regards



Richard

[TonyP]

It seems that the heated or coated windscreens on Fords and Renaults, maybe other cars, interfere with the signal, especially if the windscreen is on.



I have my receiver underneath the rear parcel shelf. It seems to work well as there is not so much interference in the back of the car, and it is easier to hide the receiver and the wires. The foam padding of the parcel shelf doesnt make any difference



In my car, the back window is raked much more than the windscreen, so the receiver gets a better view of the sky.

[Gadjet]

Guys,

Unfortunately running unsheilded cables close to harnesses in modern vehicles can cause problems with signals from devices not really designed with the automotive electromagnetic environment in mind, this means most GPS antennas with serial type outputs.



The nearer you place the cable to vehicle harnesses the more lightly you will get coupled electrical and magnetic interference, sheilding will help against electrical interference but not magnetic, i.e. heated windscreens and fuel pump supply wires.



Phil
_________________
www.gadjetsblog.blogspot.com

[RichDem]

Hi Simon,



I did originally have the receiver on the far right side of the dash, like you I moved it because I wondered if the electronics were interfering with the signal. It is much better where it is now but as you would have read from my first post the problem seems to happen more first thing in the morning,



If you are interested you can buy a standard modem extension lead from PC World for £5.99, this will let you experiment with various positions within the car.



Dave I also wondered if the 9532 is more sensitive, as I said earlier I have been in contact with Simon at TDC. I will give him a call next week. I am off to work now and then Germany on business on Sunday for a couple of days so I will not have too much chance to try moving the receiver.



Thanks for all your help, I will keep you informed of any outcome.



Regards



Richard

[loiphin]

Rich,



I installed my navigator in a Jeep Grand Cherokee. I put the silver TTN2 GPS receiver in the centre of the dash, right near the windscreen. I ran the cable to the right, to the end of the dash where it meets the drivers door. I managed to push the wire in a crack between the door frame and the dash. Then underneath the steering column where all the car wiring is, till I reached the cigarette lighter socket in the centre. I tried to tuck the wiring under the dash as much as possible. When I tried it, the signal was all over the place. So I ended up pulling it all out and just having it loose over the centre of the dash. When I get a chance I will try and make another plan. Not sure of the baud rate, as I just leave it on "Tomtom Navigator GPS" setting in the GPS setup screen. I guess the cable is unshielded, except for the ferrite filter in the connector (I think it has one.... read it somewhere)



Regards,



Simon.

[RichDem]

Hi Dave,



Sorry if I was not too clear, I have the receiver to the left of the dash, right under my tax disk holder, there is also a gap in the heating element here. I have already extended the cable using a modem extension.



Maybe I will experiment with the position of the receiver within the car again.



Richard

[RichDem]

Has anyone tried using Navigator 2 in SIRF Mode, I tried with my 9532 and my position on the map was unrecognisable and also I noticed the speed reading was also wrong.



I thought Navigator 2 was compatible with receivers running in SIRF.



Richard

[RichDem]

Simon,



Just out of interest what car do you have Navigator installed in. I have a new shape Mondeo, like you I have the cable running down the left hand side of the dash, under the glove compartment and around the centre console. I was convinced at first it was something to do with the heated windscreen in the Mondeo but I am not so sure. Another guy I work with has exactly the same problem with a 9532, he has a Focus. I saw him today and he told me he had used his old Destinator GPS (9531) for a couple of days and it was perfect???



Apart from the chipset his receiver was set to a baud rate of 19200, when he went back to the 9532 the problem was there again.



Any ideas Dave?



Richard

[Dave]

Simon, this can happen, I did see this in one car. It really depends on how good the car electrical cables are shielded. What you can do to try and avoid this is to shield the cable, I've heard tinfoil can do the trick, but it won't look too good. The other thing you can do is purchase ferrite blocks and clip these to the Leadtek cable and this might help reduce this effect.

[loiphin]

I have a TTN2 setup with the TTN2 GPS receiver and a iPAQ 3950. When I routed the GPS receiver cable around the edge of the dashboard to underneath the car, so that it would look nice, it would cause my GPS to consistently lose the satellites. One minute I would have 5-8 satellites, the next nothing. When I removed the cable and "draped" it over the centre of the dash to the cigarette outlet, all started working again properly. It must be picking up some interference from the car electronics. I haven't tried another plan yet... but will at some stage.



Simon.

[Dave]

Richard, You can try the 9600, but not in NMEA, it won't work.

[RichDem]

Hi Dave,



This morning was much better, the signal only dropped out a couple of times, I don't know if it is just a coincedence or whether selecting the Emtac Crux driver has helped.



Maybe there is something happening in the upper atmosphere at that time of the morning which causes problems with the signal getting through.



I left my office at 10.00am yesterday to travel to Croydon and had 9 sat's virtually all the way. That was driving through built up areas such as Putney, Wandsworth & Streatham. It would seem that a couple of hours made a substantial difference.



I understand what you said about the GPGGA not really making a difference, last Thursday with it set on 1 the signal dropped out regulary, I pulled over and changed it to 2 and for the rest of the journey it was perfect. I even deliberately drove home via some narrow country lanes with heavy tree cover and never lost the signal. Again maybe this was just a coincedence.



I would like to try the 9600 baud rate setting as Leadtek suggest but as I said in my other post I have so far been unable to change from 4800.



I have to work in SE London on Saturday which will involve driving through built up areas which previously gave me problems so I will see how it goes.



Richard

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