are they all slow to find satellites?

Define "slow to find satellites." A lot depends on the length of time since it was last used as well as where the unit is while searching. My vehicle remains outside, so I turn mine on while walking from my door to the car. By the time I get in the car, get the unit placed and power connected it has usually locked onto enough satellites that the unit has unlocked and is ready to navigate.

And if you turn it on while you are already moving it will take longer to acquire the satellites.

Hi I define it as several minutes, could be up to 10.
I understand that it is affected by cold boot, moving, and some sort of coating on the windshield, but I'm wondering if getting a new garmin will help, or if it will be more of the same. ie, any new chips or gpsfixes that come with the new models? I think mine is about 3 years old??

My 340 takes a minute or two and my 270 takes 5 - 10 minutes.

Garmin did change GPS receiver chips a few years ago. Yours may have the SiRF chip or it may have one of the others. Mine has the MTK and I have no problems with satellite acquisition other than the first time it is turned on in a location far from the last time it was on - like across the country. The unit just takes a little longer - like about 15 seconds or so. It's always ready to go just about the time I'm ready to start driving.

the newer units can be MUCH faster than the 760 (which I own). The newer 265WT often has full sat lock by the time it powers up, even if it has been off for several days. The only time that doesn't seem to be true is if you have moved locations since it was last powered off.

For the most part, the newer units "can" be much faster.

I have also noticed on mine that if i shut it off a block or so from the house then turn it on at the house it will take longer to come on line

I don't know how many other Garmin models are like this, but my 855 does not really turn off so long as the cigarette lighter socket it is plugged into still has power. This has the disadvantage that it is draining slightly over 100 mA from your battery all the time, which is no good at all if you leave your car for more than a week at a time or so, but over a day or two is not serious at all.

The huge benefit is that it generally has a full set of satellites and is ready to go the moment I turn it on, even though it has been parked in a garage that only gives it a view of about half the satellites. If you park inside a reinforced concrete building or something else that blocks satellites even more effectively, this would not help so much, and if your car disables power to the cigarette lighter or accessory outlet when you turn off the ignition, it won't help either, although at my location the 855 still generally get satellites from a true cold start in about a minute.

But your very slow acquisition time may be partly an oddity of your specific location at startup, so the experience of others may not be a reliable guide to your prospects.

Want to sell your old 760 when you get a new GPS? If so, how much do you want for it?

Mine usually finds the satellites within a minute or so (1490T) though I've noticed that within the last month or so the signal strength has only been about half what it was before and takes a little longer to acquire the satellites. A bit strange.....

I have an old Nuvi 680 which takes 2-10 minutes sometimes. My newer Nuvi 1690 takes at the most 1 minute. Timings have been while parked in the same car at the same time and same location to the windshield.

Before I can back out of the garage it is ready to go.

thanks everyone, I may give garmin another look!

to the person asking about buying- you name the price you are interested in paying and I"ll let you know- prob best to do this by private message

thanks

I just turned my 1490T on to test the acquisition speed, inside. Exactly 60 seconds. It was loast on about 12 hours ago.

I've seen it take several minutes if it has been a while since it last obtained a lock and I've seen it acquire the satellites in less than 10 seconds when it had recently been turned off and I turn it on outside in an area with a good view of the sky.

As another person posted, if I leave it plugged in while its turned off it has the satellites immediately,

My 260 takes about 30% longer.

The newer units that end with the number 5 are much faster acquiring a satellite fix than the older units that end in 0. My 265WT locks in by 15 to 20 seconds or sometimes even faster.

i had that problem with my other nuvi the 750 and the 350.. if you dont use them for a week or so. they take a while to find the satellites.. but if you just turn them on every so often in clear view of the sky.. let it aquire.. may take awhile.. but next time it will find the satelites quicker..

more ya use them the quicker the aquisition.

Almanac
The receiver needs an almanac to tell it roughly where the satellites are in the sky. It uses this almanac to help it determine which satellites to search for. The almanac is good for about a week, so if it has been longer than a week, it will need to download a new almanac which will always take 12.5 minutes after it finds the first satellite. The age of the almanac will determine how long this first satellite will take to find. Newer receivers typically store the almanac in flash memory, but some store them in battery backed up memory. For those, when the battery is dead, the almanac is lost and the factory loaded almanac is used at start-up.

Location
If the receiver has moved significantly since last use (usually quoted as 500 miles), it will take longer to find satellites because it will be looking for satellites visible from the old location. Also, if it is moving then it will take longer to find satellites.

Time
If the date/time of the receiver is incorrect, it will also take longer as it will be looking for satellites visible at the other time. This time is lost when the battery dies, making it take longer. Once it finds the first satellite, it will use the time from the satellite.

Then there is the physical location of the receiver and the issues with blocked and/or reflected signals, and interference with other signals and atmospheric events.

Additionally, there can be very rare times when less than 4 satellites are actually visible in the sky. I have only seen this once for about 10 minutes almost 12 years ago. With less than 4 satellites, the receiver cannot get a solution unless it uses alternate sensors like an altimeter or trying to fix the altitude on the surface of the ellipsoid.

The test would be to let it get a solution for at least 12.5 minutes, then shut it off and back on and see how long it takes to get a solution. If this takes a long time, then there is a problem (or maybe just a bat internal battery)

I have a nuvi 265WT. Even after being off for several days it will usually acquire a fix in a minute or less even inside the house. The longest it has ever taken is about 10 minutes, but I was in an airplane doing 400 + miles per hour trying to acquire satellites through that little cabin window and obviously a considerable distance (and altitude) from where the unit was turned off.

Here's the low-down on HOTFIX >>

http://www2.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY...

All 3 of my Nuvis (755, 1350, 3790) have no problem finding the satellites. By the time we pull out of the garage and onto the street I have satellites.

There are a number of variables that determine how quickly a GPSr can get a lock on its position and most have been mentioned here. I would start by placing the 760 in a vertical position with a clear view of the sky and turn it on and time it as to how long it takes to get a fix; then leave it on for another 15 minutes to be sure all the data has been received to build the almanac table. Then turn it off. Wait an hour or maybe a day and then repeat placing the 760 in same place and time it again. If it only takes a couple of minutes at most, you're gold. If it still takes 10 minutes, then something isn't right. If an SD card is installed, try removing it and time it again. Be sure your Favorites are backed up and try a hard reset. After a hard reset, it may take longer for the 1st acquisition until the almanac is restored. I'm assuming you have the current firmware/software updates??? I have a 750 and I think we share the same version 4.90. Some have reported difficulties with 4.90 and have reverted to 4.80. I can't think of anything else you could try.

Does it do it only on the first link up of the day?

i know my 350 takes a little wile to lock on the very first time of the day but after that it locks on right away..

I have a nuvi 750 and wouldn't take for it.
I don't use it but two or three times a month unless I am on vacation.
If it's been a long time since I have used it I try to turn it on while I am getting ready to go and when I get to the car it is ready.

If I turned it off before I got home it takes a long time to boot up.

Some times it takes too long but I just hold the on switch to the left till it goes black and then turns back on and it starts up faster.

The Nuve 750 has all the functions that I like so hopefully it will last me a long time.

I didn't know that! My 255 is very fast, much like your 265W - about 15-20 seconds even when cold and moving.

I've had both a StreetPilot C530 and a Nuvi 1450 and neither of them EVER took more that a minute or so to acquire their satellites.

Phil

does the same thing ... sometimes the start-up process is rather quick (~5-10 seconds), other times it can take up to three minutes.

--

it's the dog's fault

...w/ 1490T even w/ unobstructed view of horizon.
Bad, bad, dog!

When I turn on my 1450 it takes about 20 seconds to load maps, show splash screen, ect. By the time the main screen is on, it's good to go.

You touched on a point that I had noticed and I'm wondering if there is a way to get around the condition. When I've flown to Florida with the Garmin 255W in my carry-on, the GPS took FOREVER to get a fix once I was in the rental car. I've also noted that if I turn it off on the way home from some trip (even in the same state) and then turn it on at my home a day or two later, it takes a very long time to get a fix.

Is there anyway I can "set a location" ahead of time, even if it is a town, so that it "thinks" it is at the last point where it was turned off??? That would hopefully make the wait to get a fix much faster?

In Florida I was on the interstate in Orlando in the rental car before I finally got the routing to work.

The problem isn't that the GPS has to find its new location, the problem is it has to receive the satellites. In order to find its location, it has to measure the time delay to several satellites. After it gets the time delay it then plots all possible positions that would give the same delay. But in order to do that, it needs to know where the satellites are. It needs to download data from each satellite that gives that satellite's exact position in it's orbit. That takes time.

So lets say you were in CA and your GPS was on and had a good fix. Then you hoped in your transporter and teleported to NY along with your GPS, you would find that your GPS would loose its fix even though you didn't turn the it off. The reason is that there are different satellites now in view and your GPS doesn't know where they are in their orbits.

I hope this helps.

My Garmin GPS, from time to time, has been slow to find satellites. I found that if I go back select Recently Found and choose the same route, it will magically find the satellites faster.

I have a 265wt and it has always been fast to lock in.Can get a signal by the time I pull out of the garage.

The receiver will use its last known position, its date/time, and its version of the almanac to determine rough orbits of the satellites. Typical receivers today will have 12 or so channels, and can track one satellite per channel. The receiver will at first only be looking for satellites that it thinks are visible. If the location, time, or almanac are not current then you could have the misfortune that all the satellites that are actually visible will be thought to be visible. In this case the receiver will at some point timeout and go into search the sky mode where it will cycle through all satellites.

Once it gets a satellite, the ephemeris data for that satellite, giving an almost exact satellite orbit and the time, every 30 seconds. The data also sends out the almanac containing rough satellite orbits, but it takes 12.5 minutes to sent the entire almanac.

It will take at least 4 satellites before the receiver can get a fix on its location. That is because there are 4 variables that it must solve for latitude, longitude, altitude, and time. It gets a little detailed in the math, but the satellite signal contains the exact time of transmission and from the ephemeris orbit it can determine the satellite position at time of transmission. Using the receiver clock it can get a time of reception. Knowing how fast the signal travels, the speed of light (delayed by the ionosphere and the troposphere which are only modeled in consumer grade receivers), and the time the signal traveled it can determine your distance from the satellite (but it also have to account for the rotation of the earth). With the four locations it can determine how far off the receivers clock is by adding a bias until the other data lines up.

sire1234 has a Garmin. My old Garmin handheld would ask if the unit had been moved when it timed out before entering search the sky mode. I assume if I answer no that it would go through another round of trying the visible satellites. Other than entering the time, that is the only input that I had.

I have TomTom's for my cars and there is no way to input anything other than the time. I can connect to my computer and download the latest ephemeris data (also contains the current almanac) for quicker start ups.

Maybe someone else can report on the Garmin input capabilities, but I would expect that setting the initial position is not an option. Since the units typically have a small battery for short duration operation, maybe you could take the GPS out and fire it up while in line for the rental or walking to the rental. It may not be able to get a good fix, but if it can get any signal, it can start gathering information that will help it get a fix faster once it has a clear view of the sky.

If you are traveling on an airline that permits GPS use in-flight (many do but quite a few do not) then one practical solution to your specific dilemma is to pull the GPS out of your carry-on bag once every few hundred miles, turn it on and get a position, then turn it off (to save battery power).

If you have a window seat, and especially if you hold the GPS pretty near the window, more often than not the acquisition time will be under a minute, so long as you are no more than a few hundred miles from the previous fix. If you don't have a window seat, your luck in getting a fix quickly or at all will deteriorate, as the basic problem is that your GPS has to see four satellites through the windows.

The primary goal is to take a fix within a very few hundred miles of your destination, so that both the satellite information is fresh, and the position estimate it is using to decide which satellites to look at doesn't slow things down.

Regarding permission to use the GPS, Joe Mehaffey has for years maintained a helpful GPS website, one page of which is devoted to a frequently updated airline list. If you start typing "GPS allowed on flights" into a Google search box you'll probably see this page of his site near the top.

I have a nuvi 3790LMT and my main issue with it is that sometimes it may take several minutes to lock onto the satellite. I have updated it as much as I can figure out. Any ideas as to why??

Not sure if this will be helpful or not, but I had a 255w for a couple years and found that over time it was taking longer and longer to acquire a satellite lock (up to ~7 minutes).

I recently replaced it with a new 265wt and found that it acquires much quicker (within a minute if I've used in the last few days). I don't know too much about why there would be such a difference, but it definitely seems like they 'wear out' with time.

I do notice that the more often you use your GPS it will acquire quicker on the next use.

Don't use it for a good while, it will take a while to lock on satellites.

I do know on a gloomy or dark days (heavy clouds) will take longer but not hinder the performance while locked on.