Ratsneve

IMHO, 1. This shouldn't matter if your air is recirculated from inside the house. If it is filtered from outside air then maybe there is a pressure differential that would affect. On the other hand... I don't think, considering what results you are looking for, it will matter in any case. The key to the test is to see dynamic pressure changes recorded when the unit is Off. 2. No, I don't think anyone can do this. It is an oversight that a software change might include in the list of things you can reset. But enough people have to tell Garmin to do it because they are otherwise likely to be oblivious to the need. 3. Either should work and record when Off. Try them both and see. If they both give you dynamic change when On they both should give you dynamic change when Off.

Wow, your s/n is much earlier then mine at 18Z030nnn. I've got a feeling that these s/n ranges are meaningless now and Garmin is just tossing whatever repaired units they can turn around back into the mix. So far all my testing points to no dynamic trending on my unit when off--all I end up with is a straight line between dynamic barometric points drawn when the unit is turned on. In fact, the record looks identical to what I get when I have Pressure Trending set to Save When Power On instead of Save Always. If I didn't know any better (and I don't) I'd say that this Pressure Trending switch doesn't work at all on my unit.

Compass | Options | Bearing pointer. That's how you switch to the regular looking compass. Compass | Options | Course pointer. That's how you switch to the VOR-looking compass. You don't need to use Sight 'N Go to get it. 0.25 mi is the distance between dots on the CDI (course deviation indicator). You can change that by simply zooming in or out. From the default compass (bearing pointer) I cannot get the course pointer (VOR) until I initiate a Sight 'N Go first. And this sets up a Sight 'N Go waypoint and course. I have to clear the course and delete the waypoint before the compass will revert completely (CDI disappears) and the compass is once again back to the default. I'll play with this more on the next trip. I wonder if anyone uses this type compass while driving a route? And I wonder how well it works at walking speed with the 2-axis electronic compass turned on?

I understood and wasn't questioning the need to recalibrate after a battery change. What I was trying to learn was whether after the batteries are changed and before recalibration if you experience/see errors of 90 to 180 degrees or not? It sounded like you didn't and if that is true then maybe Garmin still needs to tighten up something in the software if these wild errors could be eliminated? (If I'm beta testing Garmin's Colorado at my expense I'm going to be anal about it.)

Oh, course pointer? It should be in the options menu on the compass page. That's funny. This led me to Compass | Options | Sight 'N Go | Lock Direction | Set Course and low-and-behold...there is the compass decked out to look/function like an aircraft navigation VOR (VHF Omni Range). Does anyone know why there is a "0.25 mi" just outside the compass wheel in the upper right? Its value does not change--or at least I have never seen any other value there. I wonder if it might be the distance between the dots to estimate how far off course you are? Thanks. Now...how do I get rid of it if I want to revert back to a normal looking compass? Seriously, I couldn't figure out how to revert back.

It's called a "pitot" intake. All altimeters have them. My 76CSx has one. Pitot was the name of the French scientist who developed the "pitot tube" which is used to measure fluid velocity. On an aircraft this would be airspeed. The aircraft altimeter (barometer) hooks up to a "static port" on the side of the fuselage. I guess this little pinhole on the Colorado line (not the one that is plugged at the bottom of the cover but the one near the top between the case lip and the battery compartment seal) might best be called a "static port".

From the compass page you can select Sight N Go from the options button to do what you are asking about. There are not any instructions in any Colorado literature that I can find but the instructions on how it works are in the 60CSX manual. I see it on my compass page now but I could swear that the Sight N Go was missing before I just calibrated my compass I'll check it out. Thanks. I don't remember using Sight N Go before but I must have. I actually thought I was going to some waypoint I'd set? Things are very sketchy now. It certainly sounds like we need a new and thicker Colorado manual one of these days.

Hi George, It sounds like you are saying that even after you replace the batteries but before you calibrate your 300 you never experience this 90 to 180 degrees off situation? ...That calibrating just gets the compass spot on regardless of what the voltage changes occurred from changing out the batteries? That should be the case with my 400t too since it is hardly any different from the 300. Unfortunately we cannot correlate s/n differences since the 300 and 400t use different ranges and nomenclature in the number. The 400t's start off with 18Z followed by a six digit number. Mine is 18Z030nnn. I wonder if I only calibrate right after a fresh set of cells is installed and don't repeat the calibration until another fresh set of cells is installed if the compass will still go off on a tangent or remain very close to its calibrated direction? There is something else that throws off the compass besides changing batteries but I forget what it was I hear/read of?

It may be an engineering oversight/design change that was fixed early on by sealing the hole. The hot glue seal is now essential as if it failed water could/would leak into the SD card slot bypassing its O-ring seal. If you remove the cover again and follow along the center line of the unit toward the top you will pass the battery compartment area and past its seal. Before you reach the lip of the unit that the cover butts up against there is a similarly manufactured small hole into the unit. This is likely where the barameter senses air pressure as it is located outside the sealed off areas when the cover is in place. My guess is that very little water would flow through either of these holes unless there was some differential pressure.

Maybe, but I'm not so sure. Michael is running the same firmware we are. His unit works, ours do not. Sounds more hardware-ish to me. How would that be a software bug? My non-working unit is going back on Monday. Michael, would you indulge us with the serial number on your unit? Maybe the newest batch has the presumed hardware issue fixed. My non-working unit is 169055*** Model and s/n please. For instance... My current non-working unit is a 400t s/n 18Z030nnn. I think the 18Z is significant with the 400t at least. The 300's seem to have a different style or range of s/n.

But prior to calibration after battery change is the electronic compass off 90 to 180 degrees or do they stay reasonable close to North?

To be honest I find it strange that the CO electronic compass goes so far off base just because batteries are changed. There must be more Garmin can do on this subject. I will keep the issue open in my list. Another quick compass question on the CO 400t... When I was playing around with my first unit the red compass arrow had a section that would break out moving off left or right. I was intrigued with this presentation as it reminded me of an aircraft VOR. With my first replacement now (I'm not hoping for any others) I've been unable to get the compass arrow to function this way. What was that mode--How do I get it back should I prefer it? Thank you.

Here are my results at last... Tracking was On... Hooked up to USB cable with batteries installed but was turned Off at unit. [Heavily Edited] I've made a HUGE goof and have to do the test all over again.

So how do you clear this trend data? Is it saved in some file that can just be deleted?

Okay, thank you both. I just wanted to be sure I wasn't missing something on this issue. I wish I could edit the title differently but I can't.

An interesting question. I left my unit plugged into the external USB when I turned it Off. I'm assuming that when the unit is Off that external power if still plugged in is removed and that the unit is running on battery. I'm thinking this is true because when I unplug, as I just did with the unit still Off, neither the CO nor the PC registered that the cable was unplugged.

What is strange is that you may be the only one posting that has working dynamic trending with the unit turned OFF. Couple that with some including myself maybe not understanding the problem/display correctly and Garmin maybe in denial that there is a problem and I'd just stick to your guns and wait for the dust to settle. One thing I'm doing different in my second test is to have tracking turned on. I normally leave tracking turned off. But the unit is stationary. It will be very unreasonable (unacceptable) if the unit has to be moving in order for unit off trending to work. Is your tracking turned on or off during this last test of yours?

Does it make sense and is it acceptable to the geocaching GPS gang that when you change out the batteries on your Colorado (Oregon? Any Others?) or perform other "unusual" tasks such as turning the unit ON or OFF the 2-axis electronic compass can or will read off by 90 or 180 degrees and in some cases stick there until the compass is calibrated--if you are using it? If not acceptable does Garmin know it and are they trying to fix it and likely will one day? Is recalibrating these electronic compasses something all GPSr that have them frequently require? Thank you.

I've got a Garmin recent Garmin replacement s/n 18z030nnn. What purpose other then confusion does the Unit ID number serve...or the s/n for that matter? This pressue trending discussion is wierd because: a.) the online PDF manual (in color) is dated October 2007 while the hard copy (in b/w) that came with the unit is dated March 2008. b.) the p. 32 Altimeter Setup discussions are identical in both--why focus on the PDF manual? Did you "assume" it was morst recent? c.) contrary to both manuals that mention a 15 minute interval and your discussion I am clearly measuring an 8 min. n-sec. interval. I'm willing to change "clearly measuring" to "I don't know". d.) I've tried with the unit turned off but have been unable to see the screen flashing at all at any interval. I'll watch it again tonight when going asleep--if I can stay awake. Last night while the unit was turned off it started measuring a linear straight line from 11:04 PM to 7:14 AM this morning at an 8 min. n-sec. interval. When the unit is ON the pressure trend line can and does change direction and degree of slope both before turning the unit OFF and after turning it back ON but while off it is one linear line. Can someone explain the sense in this? When you turn the unit ON again it recalculate the this linear trend line based on the ambient pressure when the unit was first turned OFF to when the unit was turned ON again? The only points of the line that are accurate then are the start and end points--this is the trend? Lastly, although there is an option to reset Elevation Data when I Apply the reset it has had no affect on this elevation/altimeter/pressure trend data. ...Yet I have in the past seen this bar graph reset itself by some function I have done. How do you reset/clear the data? Clearing the Track Log and/or turning the Track Log off does not clear the Barometer/Ambient Pressure data either. Turning the pressure trending state to Power ON only and then turning the unit off does not clear this data either. Is there no way to clear this? Although I find it hard to believe Tracking is tied into this problem I will test again.

The OP is still missing.

It is of course your choice, but I and others make the system work the other way. I get very very few unsolicited calls, email (unsolicited spam that isn't filtered out by my ISP), or junk mail. I work dilignetly to keep it so, though I slip once in a while.

"Ambient pressure" is the actual pressure... "Barometer" is the ambient pressure corrected to sea level altitude. Shoot, I use to know this. It is very important when flying to determine your actual AGL (above ground level). It is coming back now... So if you are at sea level the ambient and barometric pressures are the same--always.

What is the difference between "plot ambient pressure" and "plot barometer"? [Heavily edited to move main body to another thread.]

I have a recent replacement 400t from Garmin and have installed the 2.6 version. I haven't used it much but I experienced one screen lockup requiring battery removal; one compass going 180 degrees off and sticking there; and one unscheduled shutdown when I was playing around zooming out in the 3D View. The principal reason it was replaced was for the erratic compass behavior and the location point extreme wandering while moving. With the new unit the later hasn't happened once and the compass is fine except for the one hiccup so far. Has Garmin told anyone yet that these shutdowns and lockups are softare only and not hardware? If hardware replacement fixed the location point wandering way off and fixed the erratic compass then I'll start wondering now if we are going to get by with software updates fixing these other two issues? If Garmin releases another software update we can start off with a shorter thread again.

I would like to try hanging my GPSr from an attractive neck strap of some sort--not just a thin shoelace. Any ideas of where to find something like this? Thanks.