Slow TTFF for Holux 210

Robin2 · Posted: Wed Nov 03, 2004 9:36 pm Post subject: Slow TTFF for Holux 210

I have a wired Holux GM210, which I bought about a year ago. When I first bought it a cold start (after not having used it for a few days) took about 3-4 minutes to get a fix. Recently, this has been 10-12 minutes - nothing else has changed, it is still mounted in the same position in the same car. I phoned Holux UK who told me that a cold start time of anything up to 45 minutes was within tolerance. This is obviously unacceptable, it is quite impracticable to wait that long for a fix before starting a journey.
Can anyone recommend the best wired GPS receiver I could get to replace the GM210, preferably using the same 6 pin plug connections so that I can just plug it in to the Y connector between my cigar lighter and the iPAQ2210. I don't want the hassle of bluetooth, and I would prefer not to use a CF receiver, as with TTN3 and CP5 I use both cards for map data.
Robin

Dave · Posted: Thu Nov 04, 2004 9:45 am Post subject:

First off, anything from 12 mins to 45 mins is a factory fix, so this isn't a cold fix. You may have been talking to the wrong person, or he got it muddled.

Anything from 30 seconds to 12 mins is considered a cold fix. It takes 30+ seconds to download the ephemeris table (for a cold fix). If your GPS isn't holding the almanac say the battery on the circuit board (or capacitor) isn't holding a charge and losing the almanac data, then it can take anything from 30 seconds up to 12.5 mins to obtain what's called a factory fix. Now if you are still not getting a fix after 12.5 mins it's because you have a bad view of the sky, or you have an athermic windscreen.

If you are sure nothing has changed, then I suspect the battery on the Holux is dead or not charging, but still it should only take around 12-15 mins to download the almanac and ephemeris data, which suggests you may not have a clear view of the sky or you have some localised interference. Try placing the antenna on the top of the car and see if it obtains a fix quicker, or try driving to another location and then plugging it in.

I haven't known a holux to lose it's battery, but it's possible over time. Any GPS Receiver as a replacement will work, none will support the same 6 pin connector so you will get a different charger lead with a new GPS. Personally I find Holux one of the better receivers. The new GR-211 is a really nice (very small) GPS that we reviewed here, but if you want to stay clear of Holux then a RoyalTek Sapphire, Leadtek, GlobalSat or any other cabled mouse would be okay. There have been a lot of complaints on here about the Rikalines so you may want to read these posts before going for a Rikaline.

Robin2 · Posted: Thu Nov 04, 2004 4:41 pm Post subject:

Thanks for your helpful reply Dave. No, it hasn't got longer than 12 minutes so far, but (perhaps coincidentally) this is much longer than the cold starts I did when the unit was newer. If I have used it within the previous couple of days it is, as expected, much quicker. Once it gets a fix, it works perfectly - it never seems to lag much behind my actual position, and typically on the open road I can see around 7 satellites. So if it doesn't get worse than 12 minutes, it's normal, but anything above that will indicate a problem.
Robin

Dave · Posted: Fri Nov 05, 2004 10:17 am Post subject:

Ok, are your journey's fairly short ? e.g. half an hour ? If so it might be an idea to have the Holux plugged in and with power for a few hours to re-charge the battery, it maybe that it's not getting enough charge, although saying that I would expect it to lose all or no data from the ephemeris table.

Leaving a GPS for a couple of days, say 2-4 days will result in a longer fix, probably around 2-4 mins, but leaving it 1-2 days shouldn't take much longer than 2 mins to obtain a fix.

Robin2 · Posted: Tue Nov 16, 2004 5:53 pm Post subject:

It's definitely too slow Dave. I used it last night and it was fine at 1130 pm. Today I switched it on in the drive before setting off, and it took a full 6 minutes before I got 4 satellites and it acquired a fix. After that it was perfect for the next 90 minutes. I'll try again tomorrow.
BTW, I was interested in the new Holux mount/amplifier/GPS receiver. Although designed to be used with a window mount, I always use a vent mount for the iPAQ 2210. Did you experiment with having the GPS receiver further back? The Holux GM210 seems to work ok if I bring it back, though my usual position is near the glass.
Robin

Dave · Posted: Tue Nov 16, 2004 6:47 pm Post subject:

This sounds like you have an athermic windscreen, but would have been affected by this a year ago, unless you have positioned the GPS slightly further away from the windscreen a year ago ?

Robin2 · Posted: Tue Nov 16, 2004 11:18 pm Post subject:

I use the GPS in a Citroen Saxo (clear glass) and a Mk 5 VW Golf. The Golf has what is called heat insulating tinted glass (I presume that's an athermic screen) but that doesn't stop me picking up 8 or more satellites in either car when it's warmed up. It has definitely got slower in the last year - it could be as you suggest, the battery inside the GPS receiver may have lost some of its storage capacity.
Robin

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