Do more expensive GPSrs have better reception than cheaper ones?

[+EconTula]

Do more expensive GPSrs have better reception (e.g. faster to acquire satellites, better readings in tree cover) than cheaper units, or is the difference in price all due to the difference in features (e.g. maps, paperless geocaching, touchscreens)?

 

Related question: do newer units have better reception than older units (i.e. is the technology improving over the years)?

 

I ask because I have been using a Garmin eTrex ever since I started geocaching 7 years ago. (That model is now called the eTrex H but it used to be just the eTrex). I am thinking of buying a newer, better GPSr. I do not care so much about the "bells and whistles" that I could get with a newer and more expensive GPSr (e.g. maps, the ability to upload geocache information, paperless geocaching). What I really want is better reception. My eTrex is nearly constantly bouncing me around, and I often find myself as much as 100 or more feet away from where I am supposed to be. It is worse in dense forest but the problem shows up even elsewhere. I want to know if the newer, more expensive units have better reception than my 7-year-old cheap eTrex, or if the additional cost of the more expensive units is just because of the bells and whistles.

[jholly]

Your eTrex is not the eTrex H. The eTrex H has a high sensitivity reciever, yours does not. The high sensitivity receiver gives better reception under tree cover. If all you want is a better receiver then the eTrex H is what you are looking for. Is the receiver in the more expensive units better? Probably not. Is the antenna in the more expensive units better? Possibly. The more expensive units have more features, compasses, maps, altimeters, etc. The eTrex H is a pretty basic you are here instrument.

[+EconTula]

Your eTrex is not the eTrex H. The eTrex H has a high sensitivity reciever, yours does not. The high sensitivity receiver gives better reception under tree cover. If all you want is a better receiver then the eTrex H is what you are looking for. Is the receiver in the more expensive units better? Probably not. Is the antenna in the more expensive units better? Possibly. The more expensive units have more features, compasses, maps, altimeters, etc. The eTrex H is a pretty basic you are here instrument.

 

Thanks, you are right about me having the eTrex, not the eTrex H. I didn't notice that about the high-sensitivity receiver. It looks like every unit that Garmin now sells has the high-sensitivity receiver.

 

But what do you mean by: "Is the receiver in the more expensive units better? Probably not. Is the antenna in the more expensive units better? Possibly." All I care about is whether or not I'll get better reception. Will a better antenna give me better reception even with the same receiver?

[jholly]

Your eTrex is not the eTrex H. The eTrex H has a high sensitivity reciever, yours does not. The high sensitivity receiver gives better reception under tree cover. If all you want is a better receiver then the eTrex H is what you are looking for. Is the receiver in the more expensive units better? Probably not. Is the antenna in the more expensive units better? Possibly. The more expensive units have more features, compasses, maps, altimeters, etc. The eTrex H is a pretty basic you are here instrument.

 

Thanks, you are right about me having the eTrex, not the eTrex H. I didn't notice that about the high-sensitivity receiver. It looks like every unit that Garmin now sells has the high-sensitivity receiver.

 

But what do you mean by: "Is the receiver in the more expensive units better? Probably not. Is the antenna in the more expensive units better? Possibly." All I care about is whether or not I'll get better reception. Will a better antenna give me better reception even with the same receiver?

With the same receiver a better antenna will give better reception. Some say the quad helix in the 60/62/76/78 is a better antenna than the patch antenna in the other units. I have not seen any technical comparisons that would lead me to that conclusion.

 

As for the receiver, just about all the higher priced units all use the same GPS chip. I think the eTrex's use a different chip. Some of the older units use yet a different chip. I have not seen any technical comparisons between the units that would lead me to the conclusion that one is better than the other. Just saying that there *might* be some small difference in receiver performance between the units.

[+JJnTJ]

My old eTrex Camo has a much larger ESE in the woods than my 60CSx. On a nice, clear day in the wide open air, they're not much different.

[+Semper Questio]

My old eTrex Camo has a much larger ESE in the woods than my 60CSx. On a nice, clear day in the wide open air, they're not much different.

 

And with no scientific data to back me up, I think that alludes to where the differences really lies in the capability of the newer devices compared to the older. Standing still out in the open on a perfect day, they are all pretty much the same.

 

Now add cliff faces, trees, buildings, etc. and things become less certain.

Then start moving.

Then start moving in an erratic pattern.

Then start moving faster.

 

All of these (and probably more) add to not only factors in difference of sat signals received, but also differences in the ability of the chipsets to calculate your position from the data they receive from the sats.

[+briansnat]

Do more expensive GPSrs have better reception (e.g. faster to acquire satellites, better readings in tree cover) than cheaper units, or is the difference in price all due to the difference in features (e.g. maps, paperless geocaching, touchscreens)?

 

Generally speaking there is no increase in reception as you move up the price rage. The additional cost brings you additional bells and whistles

 

Related question: do newer units have better reception than older units (i.e. is the technology improving over the years)?

 

It's a whole new world. My old eTrex had trouble getting reception under a light tree canopy. My 60CSX gets reception in my basement with shades drawn over the windows.

 

I also have an old Magellan Meridian which in its day had a reputation for having the best reception of any unit. It pales in comparison with my 60CSX and DeLorme PN40.

 

So yes, the units with high sensitivity receivers get far better reception than the old units. The new eTrex H will give you far better reception than your old eTrex.

[+RedKrisco]

I had an eTrex vista that I absolutly hated and vowed never to use again after my first time out geocaching. I then went bought an explorist GC which I love. My etrex lost sats all the time, my GC has yet to lose any sats. And a thought about the "bells and whistles"... maybe you dont care about them because you dont have them. Once you start using some of the bells and whistles, I'm sure you will be glad you have them.

[+Smurf]

Do more expensive GPSrs have better reception (e.g. faster to acquire satellites, better readings in tree cover) than cheaper units, or is the difference in price all due to the difference in features (e.g. maps, paperless geocaching, touchscreens)?

 

Related question: do newer units have better reception than older units (i.e. is the technology improving over the years)?

 

I ask because I have been using a Garmin eTrex ever since I started geocaching 7 years ago. (That model is now called the eTrex H but it used to be just the eTrex). I am thinking of buying a newer, better GPSr. I do not care so much about the "bells and whistles" that I could get with a newer and more expensive GPSr (e.g. maps, the ability to upload geocache information, paperless geocaching). What I really want is better reception. My eTrex is nearly constantly bouncing me around, and I often find myself as much as 100 or more feet away from where I am supposed to be. It is worse in dense forest but the problem shows up even elsewhere. I want to know if the newer, more expensive units have better reception than my 7-year-old cheap eTrex, or if the additional cost of the more expensive units is just because of the bells and whistles.

 

We started with an old basic etrex, (because i already had it when we heard about caching), and were very happy with it - -but found it's loss of signal under tree cover etc very frustrating and went out and bought an etrexH - the diferance was amazing, it even got a signal lock indoors (which the old one never would)

 

So - If you are happy using the basic etrex and just want a better reciever I would say go for the etrexH

 

The only reason I wouldn't recomend it as a starter unit is the extra cost of the cable needed to conect it to the computer - as it uses a none standard conector and is suplied only for a serial port, so most people would need a serial to usb adaptor as well.

Add the cost of these extras to to price of the unit and you can be better off getting a dearer unit that connects using a standard mini usb cable

 

 

*** edit to add that we have now moved on a bit and now cache with an oregon and a PDA running Memory map and tomtom ***

Edited December 3, 2010 by Smurf

[+Highland Horde]

I started with the Venture HC. It was a pretty good unit but I wanted something that could hold more that 500 caches so I upgraded to the Dakota 20. Before getting the Dakota a tried the 62s and the Oregon 550. All 3 of the newer units grabbed sats quicker, got waas lock (which the venture hardly ever did) and just seemed more consistent. The Dakota is the cheapest of the units I tried and it seemed to be the bells and whistles that made the difference in price. There may be a difference in reception under heavy cover with the 62s as it has a different antenna than the oregon/dakota but I haven't had any issues. The only time I lost reception was when I was at GZ and my dakota was in my front jacket pocket. I was crouched over the cache under heavy tree cover so I am pretty sure any unit would have lost reception. As soon as I stood up it grabbed sats again. It took a minute or so to bring the accuracy down but not too bad since I couldnt see the sky

[+John in Valley Forge]

Related question: do newer units have better reception than older units (i.e. is the technology improving over the years)?

 

 

In my limited experience the answer is YES.

I have two handhelds. I wont name them to avoid the Ford vs Chevy debate

One is older and has a SiRFstarII chipset. The other is new and has a SiRFstarIII chipset.

When I first got the new one, I carried them both on a few trips to compare them.

As others have mentioned, reception on a clear day, in an open field, is equal between old and new units. The difference is once you are under cover of trees, high rocks etc.

The SiRFstarII loses lock under moderate cover (trees, picnic canopies). The SiRFstarIII gets lock in my basement, under 3 ceilings and a roof.

 

As far as bells and whistles that come with higher priced models, I would say that is an issue of personal preference. Buy what you feel you would really use, ignore the rest.

I saw some units that combine a GPS and a walkie talkie. For me, that seems overkill, more things to break. I can buy a pair of walkies at best buy if I want them.

 

I would say that you should look into the interfaces for the potential new purchase (I assume you are shopping for a new one or at least considering it). My older unit has a difficult interface with my PC and the buttons on it are hard to work.

[+SSO JOAT]

There is more to the GPS than just the "reception". Yes, the radio receiver gets better as you go up in price model. Yes, a better antenna gives you better reception. Beyond that, the most important aspect of a GPS is how accurate the internal clock is. A lower quality clock gives less accurate results. A higher quality clock gives more accurate results. The manufacturers are nice enough to not give the consumer any information about the clocks they use. But, if you get a $99 off-brand GPS, the quality of the electronic components, including the clock, is going to suffer compared to a high quality name brand unit in the $400-500 range. And those don't hold a candle to a $3000 surveyor model.

[jholly]

There is more to the GPS than just the "reception". Yes, the radio receiver gets better as you go up in price model. Yes, a better antenna gives you better reception. Beyond that, the most important aspect of a GPS is how accurate the internal clock is. A lower quality clock gives less accurate results. A higher quality clock gives more accurate results. The manufacturers are nice enough to not give the consumer any information about the clocks they use. But, if you get a $99 off-brand GPS, the quality of the electronic components, including the clock, is going to suffer compared to a high quality name brand unit in the $400-500 range. And those don't hold a candle to a $3000 surveyor model.

and the clocks in the $3000 surveyor models don't hold a candle to the clocks in the satellites. I wonder if the gps unit clocks somehow sync with the clocks in the satellites?

 

Edit:As for accuracy as you buy more expensive units. Garmin rates the eTrex H at 10 meter accuracy which is the same accuracy quoted for the high end Oregons. Given the statement that a more expensive unit has better clocks and receivers I would think that the accuracy quoted would be better for a 550 than the basic eTrex. Or did Garmin marketing miss an opportunity?

 

Why are the survey grade GPS units better? Antenna definitely. Receiver? Well until we understand the quantitative factors for receiver performance that is speculation. Better clock? No doubt better short term drift performance and some other factors. But probably the biggest difference is the software installed on the unit and the level of post processing that goes on compared to a consumer grade gps.

 

It looks to me that if you want to find a geocache the eTrex H will give you the same performance and ability as the Oregon 550. But the Oregon will give you some creature features that make it easier.

Edited December 4, 2010 by jholly

[+tozainamboku]

There is more to the GPS than just the "reception". Yes, the radio receiver gets better as you go up in price model. Yes, a better antenna gives you better reception. Beyond that, the most important aspect of a GPS is how accurate the internal clock is. A lower quality clock gives less accurate results. A higher quality clock gives more accurate results. The manufacturers are nice enough to not give the consumer any information about the clocks they use. But, if you get a $99 off-brand GPS, the quality of the electronic components, including the clock, is going to suffer compared to a high quality name brand unit in the $400-500 range. And those don't hold a candle to a $3000 surveyor model.

and the clocks in the $3000 surveyor models don't hold a candle to the clocks in the satellites. I wonder if the gps unit clocks somehow sync with the clocks in the satellites.

This is the reason you need 4 satellites for a fix. The accurate time can be computed along with 3D position using the information received from 4 satellites. The clock in the unit is used to measure the relative time of arrival of the signals from the satellites. A more accurate clock would have a minuscule effect on the final results.

[jholly]

There is more to the GPS than just the "reception". Yes, the radio receiver gets better as you go up in price model. Yes, a better antenna gives you better reception. Beyond that, the most important aspect of a GPS is how accurate the internal clock is. A lower quality clock gives less accurate results. A higher quality clock gives more accurate results. The manufacturers are nice enough to not give the consumer any information about the clocks they use. But, if you get a $99 off-brand GPS, the quality of the electronic components, including the clock, is going to suffer compared to a high quality name brand unit in the $400-500 range. And those don't hold a candle to a $3000 surveyor model.

and the clocks in the $3000 surveyor models don't hold a candle to the clocks in the satellites. I wonder if the gps unit clocks somehow sync with the clocks in the satellites.

This is the reason you need 4 satellites for a fix. The accurate time can be computed along with 3D position using the information received from 4 satellites. The clock in the unit is used to measure the relative time of arrival of the signals from the satellites. A more accurate clock would have a minuscule effect on the final results.

exactly, that is why the rhetorical question.

[+SSO JOAT]

As for accuracy as you buy more expensive units. Garmin rates the eTrex H at 10 meter accuracy which is the same accuracy quoted for the high end Oregons. Given the statement that a more expensive unit has better clocks and receivers I would think that the accuracy quoted would be better for a 550 than the basic eTrex.

 

All of the "high sensitivity" units feature the same clock and processor. The clocking comparison is better made by comparing any of the Garmin "H" units to an older "non-H" unit or to say the GPS chip installed in a cell phone.

 

The clock is quite important to end accuracy. To say it is "miniscule" means you haven't looked at the level of fractional math going on to calculate your position. Time differences that are best stated as negative powers of 10 are used to figure out your location. The GPS "warm up" period is when the current orbit data is downloaded and the GPSr internal clock is perfectly synchronized to the satellite clocks. Yes, the satellite clocks must be extremely accurate so the sat can calculate it's own position based on ground tracking stations. But the GPSr clock must be accurate in order to figure out it's own location. The satellite don't figure out where you are, they just tell your GPSr where they are. It is up to the GPSr to do its own math and calculate its own position based on the distance to these other sats. Without a perfect clock in the GPSr, such calculations are going to be inaccurate.

[jholly]

As for accuracy as you buy more expensive units. Garmin rates the eTrex H at 10 meter accuracy which is the same accuracy quoted for the high end Oregons. Given the statement that a more expensive unit has better clocks and receivers I would think that the accuracy quoted would be better for a 550 than the basic eTrex.

 

All of the "high sensitivity" units feature the same clock and processor. The clocking comparison is better made by comparing any of the Garmin "H" units to an older "non-H" unit or to say the GPS chip installed in a cell phone.

 

The clock is quite important to end accuracy. To say it is "miniscule" means you haven't looked at the level of fractional math going on to calculate your position. Time differences that are best stated as negative powers of 10 are used to figure out your location. The GPS "warm up" period is when the current orbit data is downloaded and the GPSr internal clock is perfectly synchronized to the satellite clocks. Yes, the satellite clocks must be extremely accurate so the sat can calculate it's own position based on ground tracking stations. But the GPSr clock must be accurate in order to figure out it's own location. The satellite don't figure out where you are, they just tell your GPSr where they are. It is up to the GPSr to do its own math and calculate its own position based on the distance to these other sats. Without a perfect clock in the GPSr, such calculations are going to be inaccurate.

I don't think Toz or myself did not say the clock was not important to the accuracy of the GPS calculations. I said the clock, regardless of what type of unit, is not any where near the league of the satellite clocks. Hence the need to sync with the satellite clocks to achieve the accuracy. The clock in a survey grade GPS probably has better short term drift and jitter than the eTrex H clock, but the difference not enough to make a significant difference. And as a side note, the satellites do not calculate their own positions.

[+SSO JOAT]

A clock error in the GPSr of just one microsecond (0.000001) gives you a ground error of nearly 1,000 feet. When talking about speed of light calculations, nanosecond accuracy is needed. The clock accuracy in the GPSr is critical to the accuracy of the numbers you see on the screen. Buy a cheap, single chip GPSr (such as they put in many cell phones) and you're going to have less accuracy than you would with a more expensive "high-sensitivity" Garmin. Fact.

[+SSO JOAT]

*hiccup*

Edited December 5, 2010 by SSO JOAT

[jholly]

*hiccup*

Yes, I agree with this statement 100%.

[+tozainamboku]

As for accuracy as you buy more expensive units. Garmin rates the eTrex H at 10 meter accuracy which is the same accuracy quoted for the high end Oregons. Given the statement that a more expensive unit has better clocks and receivers I would think that the accuracy quoted would be better for a 550 than the basic eTrex.

 

All of the "high sensitivity" units feature the same clock and processor. The clocking comparison is better made by comparing any of the Garmin "H" units to an older "non-H" unit or to say the GPS chip installed in a cell phone.

 

The clock is quite important to end accuracy. To say it is "miniscule" means you haven't looked at the level of fractional math going on to calculate your position. Time differences that are best stated as negative powers of 10 are used to figure out your location. The GPS "warm up" period is when the current orbit data is downloaded and the GPSr internal clock is perfectly synchronized to the satellite clocks. Yes, the satellite clocks must be extremely accurate so the sat can calculate it's own position based on ground tracking stations. But the GPSr clock must be accurate in order to figure out it's own location. The satellite don't figure out where you are, they just tell your GPSr where they are. It is up to the GPSr to do its own math and calculate its own position based on the distance to these other sats. Without a perfect clock in the GPSr, such calculations are going to be inaccurate.

The satellites tell the unit the accurate atomic clock time and the ephemeris data from which the satellite's position can be computed. The internal clock in the GPS unit is not accurate enough to compare the satellite's time with the time of arrival and directly compute a distance from the satellite. Instead the GPS unit uses the difference in arrival time of the signals from four satellites to compute its location in three dimension along with the accurate time of day.

 

You are correct that the clock accuracy would effect time difference between the arrival of signals from different satellites. A clock with a error rate of 1 part per million would result in a larger error than a clock with an error of 1 part per billion. I suspect that you are correct and the higher price units may have features that allow the clock to be regulated and produce a smaller error rate. I know my Garmin has a thermometer that I suppose is used to account for temperature effect on the clock frequency. Note that the processor in the GPS can keep track of the drift of the unit's clock over time compared to the somewhat more accurate time that it computes based on the satellite's atomic clock time in the messages it receives and use this to regulate its internal clock to achieve more accuracy. That could be one reason in some units the position error is reduced over time.

[sdarken]

I ask because I have been using a Garmin eTrex ever since I started geocaching 7 years ago. (That model is now called the eTrex H but it used to be just the eTrex). I am thinking of buying a newer, better GPSr.

 

I found my first 500 caches using the older eTrex model but I upgraded to a 60csx when I realized that geocaching was going to be a long-term hobby. The 60csx gave me much better accuracy under tree cover and other situations where reception was less than ideal. The upgrade was worth every penny I spent on it.

[+EconTula]

Thanks for all of the advice. I ended up getting a GPSMAP 60CSx as an Xmas gift, so I didn't have to worry about choosing myself. Sounds like it will do very well.

[+AlohaBra and MaksMom]

Thanks for all of the advice. I ended up getting a GPSMAP 60CSx as an Xmas gift, so I didn't have to worry about choosing myself. Sounds like it will do very well.

 

That is a fine unit. Has anyone mentioned paperless to you yet? You can add a Nuvi to do that cheaply....or.....

[jholly]

Thanks for all of the advice. I ended up getting a GPSMAP 60CSx as an Xmas gift, so I didn't have to worry about choosing myself. Sounds like it will do very well.

 

That is a fine unit. Has anyone mentioned paperless to you yet? You can add a Nuvi to do that cheaply....or.....

a cheap palm.