Garmin GPS Questions

[adventureboy]

Greeting all,

I am going to be buying a Garmin GPS in the next week or so. I have been looking at the Etrex Series, the Rhino series, and the GPSMap 60 CS version. The last two mentioned are considerable more expensive, but seem worth the price upgrade. My real question I guess is this: If I do not need radio contact options what would the Rhino 130 offer that the GPSMAP 60CS wouldn't. Or the other way. Remember I do not need a radio. The etrex series looks nice, but I feel that the internal antenea would not be great under overhead cover and cloudy days. Plus I have heard a lot of stories about the little thumb stick breaking. Any leads would be great. Thanks

 

[Mark]

I have an eTrex Summit which I like a lot. It has a built in barometric altimeter and compass. It does not have map display capabilities, but I don't miss this feature. The built in antenna has always worked well for me in the Whites and the High Peaks if you keep the unit high on your body. (I leave mine in the top pocket of my pack and very rarely lose signal.) Clouds will not affect signal reception. Not all of the eTrex series has the joy stick. Mine only has buttons on the side which look pretty bulletproof.

 

[DougPaul]

I have had an eTrex Vista for several years now and have been considering upgrading to the 60CS. Either is a good unit for hiking. The unique feature of the Rhino is that it transmits its location, but that is only useful if someone else in your party also has a Rhino. (If I want an FRS radio, I carry a separate (and much cheaper) unit.)

Don't worry about the internal antenna--it is fine. GPS is essentially unaffected by weather. BTW, both units have an internal antenna.
There is a lot of unjustified religion about the antenna types running around--tests by knowledgeable people show only a rather limited difference, if any. (One itiot claimed his unit worked poorly until someone else pointed out that his thumb was over the antenna--flesh absorbs the signal.)

I waited for a unit with a reasonable amount of mapping memory to become available. The internal map significantly increases the utility--one can locate oneself on a paper map by inspection without resorting to cordinates. One can also place waypointsfrom the panel. (I have used the unit away from my computer for weeks by using a combination of paper maps and the internal map and inputting my waypoints and routes from the front panel.)

Some people have reported problems with the joystick. Mine still works.

My suggestion is that you get a Vista or 60CS and the Garmin US Topo maps (100K scale) and perhaps the Garmin 24K Topo East maps. (I have both maps--you can get by just fine on the 100K maps if you can only afford one.)

A GPS is a complex little beast--plan to take some time to learn how to use it. Many, if not most, of the reports of GPS problems are actually due to operator ignorance, not the GPS.

Lots of good info at http://www.gpsinformation.net also news://sci.geo.satellite-nav.

Standard disclaimer: GPS is not a substitute for a map and compass. Each gives you different info and has different failure modes.

Doug

 

[wally2q]

...yea!

Vista owner.

Happy.

I'm taking it with me to the presidentials this weekend.

Bringing a small photocopied section of paper map as well - for back up.

The biggest problem with reception is mountains and land features. Your torso will shield the unit from satellites, but your finger won't. If you are hiking in a canyon, with the GPS in your pocket - don't expect it to track satellites.

I've used my GPS to track my position while sitting in a 747. Keeping the unit close to that little window is all it took for the unit to lock onto 4 satellites.

Bottom line: give it clear view of the space above your head (keep the unit attached to the top of your shoulder strap of your pack.

the wall.........

 

[DougPaul]

Bottom line: give it clear view of the space above your head (keep the unit attached to the top of your shoulder strap of your pack.

If I want to record a track or use the GPS frequently, I usually carry it in small pouch attached to the top of the shoulder strap of my pack on the side away from the hill. If I just want to record a track, I keep it in the top pocket of my pack with the antenna oriented up. Another good place to carry it is clipped to the sizing strap at the back of a baseball cap. You can also stealth carry it in the crown of a Tilley hat. (You can also put an external antenna in the crown of your hat and the GPS in a more convient place, but then you have to be careful not to get tangled in the wire.)

If you were, for instance, surveying a trail, you would likely use a choke ring antenna mounted on a pole attached to your pack to keep the antenna above your head. (This is getting into professional quality equipment...)

Last weekend I recorded a good track up a treed valley with it in the top pocket of my pack.

And yes, if you put your thumb over the antenna on a Vista (located right under the globe symbol above the display) you will significantly degrade the signals.

A few mm thick sheet of water will block the signal. (Water droplets have essentially no effect.) Flesh is, as far as the signals are concerned, just a bag of salt water (even worse than fresh water).

Trees, particulary if wet, will absorb, diffract, and reflect the signals causing
weak and multipath signals. Worse when the sap is running. Earth and rock block and reflect the signals.

There are pointers to some professional evaluations of performance under trees at http://www.gpsinformation.net.

Your GPS should be fine above timberline.

Doug

 

[Mark]

I've used my GPS to track my position while sitting in a 747. Keeping the unit close to that little window is all it took for the unit to lock onto 4 satellites.

I got scolded by a flight attendant for using a GPS on an airliner. I was bored and tracking our progress with the GPS hooked up to my laptop. Apparently, GPSs are still on the list of devices that allegedly will interfere with a plane's navigation system.

Puh-lease!

 

[adventureboy]

helpful

Thanks for the insights theyt will be helpful in teh comming weeks.

 

[DougPaul]

I got scolded by a flight attendant for using a GPS on an airliner. I was bored and tracking our progress with the GPS hooked up to my laptop. Apparently, GPSs are still on the list of devices that allegedly will interfere with a plane's navigation system.

This is a constant theme on news://sci.geo.satellite-nav...

The FCC does not prohibit GPSes, the FAA leaves the decision to the airlines--different airlines have different policies: see http://www.gpsinformation.net/airgps/airgps.htm.
Some airlines post their policy in their inflight magazines. Ultimately, it is the captain's decision which applies (by FAA law).

From a technical standpoint, it IS possible for a handheld GPS to interfere with an aircraft's electronics systems. (All GPSes unintentionally emit some radio signals.) Just unlikely. (Laptops are generally a bigger hazzard, but there is economic incentive for allowing them...) There have been ancedotal reports of consumer electronics interfering with an aircraft's navigational radios.
Trade-off: passenger enjoying his electronic toy vs. possible aircraft accident.
Bottom line: Some airlines just don't want to bother and aren't losing enough business because of it to care.

Even airlines which allow GPSes, restrict them (along with all other consumer electronics) below 10K ft during landing and take-off.

Some flight attendants mistake a GPS for a cell phone (illegal by the FCC during all phases of flight). Make sure the flight attendant understands that it is a GPS, and if still denied, you can ask politely if the captain will let you use it.

You can also send a polite letter to the airline saying you will take your business elsewhere because of this policy.

BTW, a GPS is only legal if it has no wires connecting to to external devices, so a stand alone GPS is legal, but connecting it to your laptop is not.

More info:
http://www.gpsinformation.net/
http://www.gpsinformation.net/airgps/
http://www.gpsinformation.net/airgps/gpsrfi.htm
http://www.gpsinformation.net/airgps/airgps.htm

Doug

 

[WildPeaks]

Adventureboy,

Get a 60cs. They're more $$$ because it's the better unit out of the ones you mentioned.

Tom

 

[Nessmuk]

This is a constant theme on news://sci.geo.satellite-nav...

You can also send a polite letter to the airline saying you will take your business elsewhere because of this policy.

Is this really a rational cause to dump business from an airline? While I can see the recreational aspect of using a GPS during a long boring flight, it hardly serves any other purpose for a passenger. A business person may well get some productive work done using a laptop, but I can see no really productive use of a GPS outside the cockpit. If you must know your position then try map reading out the window, or practice dead reckoning skills when over clouds. Pay attention and you will be able to identify that mountain or city down below, just like you can do from the ground. GPS or not, you'll get to your destination airport just the same.

 

[DougPaul]

Is this really a rational cause to dump business from an airline? While I can see the recreational aspect of using a GPS during a long boring flight, it hardly serves any other purpose for a passenger.

This is up to the individual passenger...

I'm not trying to convince anyone how important a personal GPS should be to flying (as a passenger). However, some people seem to get quite offended if they are not allowed to use their GPS. (Just read news://sci.geo.satellite-nav...) Some even act like it is a constitutional right... (Some also seem to think that there is no way a GPS could have any effect on the aircraft.) Just trying to explain the technical and legal background and suggest a range of responses. IMHO, appropriate responses range from doing nothing to changing airlines and letters to the airlines.

That said, I enjoy using my GPS to help me identify what I see out the window, but it is hardly the most important factor in choosing an airline. I also carry a good book on the flight.

Doug

 

[wally2q]

I have my rights.....

Damn it.... if I can't use my GPS onboard the airplane, then I'll take my business elsewhere!!!!

..... after all I have a very special relationship with my GPS.... it's not just a tool.... it's a companion.. it talks to me and I talk to it, in GPS-speak: I ask it questions, it gives me answers ("where are we Mr. GPS?.... we're at: 44N-33'-28.440" x 60W-05'-59.011" wally")...... other times, it asks me questions and I give it answers ("do you want me to calibrate the altimeter using GPS altitude?..... YES...."

... so just like a small dog could run amok and bite the flight attendant's ankles, my GPS could break the airplane....... by....... say..... shutting down the engines.... right?

anyway - EMI is a real problem, but the GPS's emission levels are probably smilar to that of my fake Breitling.


the wall.......

 

[SAR-EMT40]

BTW, a GPS is only legal if it has no wires connecting to to external devices, so a stand alone GPS is legal, but connecting it to your laptop is not.Doug

This is a fascinating tid-bit. I was not aware of this one but it makes sense. If the wires are unshielded that basically makes them antennas transmitting the spurious signals with increased output making them more likely to interfere and cause problems. Speculation, but my best guess.

By the way. I have had several GPS's through the years. My current is a Etrex Vista C which I really like. About the same time my friend bought a 60CS. I can't say I wish I was him but the 60C does have some neat features that mine doesn't. Bigger screen (not a big deal), more memory (yeah I could always use that) and maybe a couple of other things I can't remember. The Quadfillar antenna seems to hold signals a little better than the patch antenna on mine but not enough that I would worry about it. He also does have the ability to get NMEA output from his serial output port. If you need to ask what NMEA is used for then you probably don't need to worry about it. I get my NMEA out from and older 12XL which I can also connect an external antenna to and I cannot with my Vista C. If you have the extra money get the 60CS, if not I doubt you will be disappointed with the Vista C.

Oh yeah. Another comment about Mapsource. Worth the money. I have the 100K topos maps and the eastern country 24K topo maps. Not perfect, but very usable. Don't hesitate to pick them up.

Just my $.02
Keith

 

[Rick]

I have taken my GPS E-Trex Vista on several cross country flights and it was pretty cool knowing where we were and our altitude at any given time. Especially with the airpseed & directionals as we us moved over the basemap (I had downloaded only California topos).

I fly US Air, and the attendants never bothered me. I did have to keep the GPS near the window, though or risk losing the signals.

 

[arghman]

If you are ever tag-teaming it, the Rino's CB features are *really* useful. Here's a personal anecdote: A friend and I were camping up in International Paper's Phillips Brook Backcountry, he brought a pair of Rinos and we each used one. We were bushwhacking to get down to a brook to go fishing and I got stung by a couple of yellowjackets. By the time I got away from the @#$@# things, he was out of earshot and I didn't feel like wading through underbrush anymore, & very worried about possible allergies (thankfully not the case) in the middle of nowhere. I was able to communicate with him via the walkie-talkie & we could each tell where the other person was. I could even create a new waypoint to show him where I wanted to meet him & then send him the waypoint over the walkie-talkie (it basically acts like a modem for GPS data). Having those features saved us a lot of grief at the time, and they were really easy to use.

I don't do much tag-team work, but if I did, I'd buy a Rino in a heartbeat, at least until someone else comes out w/ something similar. (Although the standard advice applies: never depend on electronics without a backup plan.)

I'm actually looking at a few of the GPS's by Lowrance, someone had recommended them as a good alternative to Garmin; Lowrance seems to have some better features (one of their units has MP3 capability which is gratuitous, but they give you a microphone to record voice notes, which would be ***very*** useful, a lot faster to say "we saw a black bear here and three moose" than to write it down or key it in via the thumbstick.) even though they're not as well known as Garmin.

 

[DougPaul]

This is a fascinating tid-bit. I was not aware of this one but it makes sense. If the wires are unshielded that basically makes them antennas transmitting the spurious signals with increased output making them more likely to interfere and cause problems. Speculation, but my best guess.

A reasonable and accurate speculation.

Consumer GPSes are FCC class B devices--that is they pass certain tests for emitted signals. Only an exact configuration can be certified, so allowing plug-ins would require the manufacturer to certify an impossible number of configurations.

By the way. I have had several GPS's through the years. My current is a Etrex Vista C which I really like. About the same time my friend bought a 60CS. I can't say I wish I was him but the 60C does have some neat features that mine doesn't. Bigger screen (not a big deal), more memory (yeah I could always use that) and maybe a couple of other things I can't remember. The Quadfillar antenna seems to hold signals a little better than the patch antenna on mine but not enough that I would worry about it. He also does have the ability to get NMEA output from his serial output port. If you need to ask what NMEA is used for then you probably don't need to worry about it. I get my NMEA out from and older 12XL which I can also connect an external antenna to and I cannot with my Vista C. If you have the extra money get the 60CS, if not I doubt you will be disappointed with the Vista C.

NMEA is a serial protocol. Designed for communication between nautical devices. The Vista C has no serial interface. (USB only.) NMEA is used by many other (non-Garmin) map vendors, eg National Geographic TOPO! and Maptech Navigator. (AFAIK, the non-Garmin manufacturers do not currently support the USB interfact, but are probably working on it.)

If I upgrade from the current products, I'd probably get a 60CS, although I wish it had the larger memory (115MB vs 56MB) and more detailed basemap of the otherwise very similar 76CS. The display on the 60CS/76CS/Vista C/Legend C is a lot nicer than the one on my eTrex Vista.

Oh yeah. Another comment about Mapsource. Worth the money. I have the 100K topos maps and the eastern country 24K topo maps. Not perfect, but very usable. Don't hesitate to pick them up.

Agreed. I have the same set. I find the 100K plus a more detailed paper topo to be sufficient, but the 24K is a nice improvement (but it uses more memory and covers less area). Still need the paper maps even with the 24K.

Also have National Geographic TOPO! for NE which I use for a range of scales including 24K maps. Also good to analyze altitude profiles and printing out area maps. I recommend it too. (I have heard good things about Maptech Navigator, but I have never had a good look myself.) There are things on these maps (which are digital images of paper US topos) which do not show on the Garmin 24K maps (which are derived from vector maps from USGS).

Doug

 

[kevingg]

I have learned and taught my parents the 60cs for their purchase and use. I have the foretrex 101 (wrist gps). I would never carry the 60cs, it is really of no use to someone who should have a topo anyway. The little featherweight device (foretrex) has all the same features you'd need to get out of a jam and cost only a fraction of the 60cs. You can get a state Topo program to print custom topos exactly where you plan to hike with a 12 second grid (0.2 minutes) on them so you can easily translate gps coords to your exact position on the paper topo in seconds. The print can be 1:24000 which has much more detail than the 60cs screen (1:100,000).