Poindexter
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Posts posted by Poindexter
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He said he has a Garmin Legend which does do waypoint projection. The manual explains how to do this. 515 feet is .097538 miles.
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Connect the garmin nmea data output to yellow and the garmin nmea data input to white. Tie black and green together and connect to garmin ground wire. The "H" is for High and the "C" is for common. If this does not work, you will need an rs-232 to rs-422 converter. The NMEA data standard calls for rs-422. Some manufacturers use it, most don't. Sometimes a direct rs-232 to rs-422 connection will work, sometimes not. Let me know if you need a converter.
The wiring diagram seems misleading to me. It says to connect white to the input terminal of the navigation unit. (Perhaps where it says "to NMEA input terminal" it's refering to input to the LS6000?) That input should be RX, not TX. Of course, RX and TX depends on the type of equipment, i.e. wether it's DTE or DCE. If my instructions do not work, try swapping the white and yellow wires.
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Also take a look at this converter.
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That's Pacific Standard Time, so 2am Saturday morning for us east coastie's
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But when I read the logs, a previous finder had provided coordinates of N 33 Deg. 47.280 Min. and W 117 Deg. 51.150 Min. So I was satisfied with using the very close numbers on the GC Benchmark Page.
Yes, that is only about 24' difference than the datasheet coordinates.
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You need to find a benchmark with coordinates of a higher degree of accuracy. From the datasheet for this benchmark:
The horizontal coordinates were scaled from a topographic map and have
an estimated accuracy of +/- 6 seconds.
One second of latitude is approx 100' longitude will be somewhat less depending on your latitude.
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With my Garmin, I wonder why I have to collect Location data Vertical but the Electronic Compass must be Horizontal (solved that with an external Antenna). Magellan even seems to have a better implementation of the Electronic Compass.
Garmin units use a two-axis magnetoresistive sensor chip. Magellan either uses a three-axis chip or a combination of two-axis and one-axis. There is also additional circuitry to compensate for tilt that provides roll and pitch information to the a/d converter. This is a bit more costly and requires more power.
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Yes, don't get taken on the price of the cable if you don't already have one. They are $7.45 at GPSGeek.
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QUOTE
As far as fantasy, to say that your GPSr always gets you within 5-15 feet 90% of the time, well that's fantasy!
I do not remember you ever being with me while I was looking for a cache so how can you comment on how well my GPS works, you have know way of knowing that now do you
Yes, I do. Not many of us are using survey grade receivers for recreational Geocaching. Our receivers simply do not have that kind of accuracy. You have 921 finds and your GPSr got you within 5-15 feet 90% of the time? Give me a break!
Not all trees lose their leaves and I have never seen any scientific study to back up this claim that GPSr lose reception because of leaves in trees. Can you provide a link to any study that has been done to prove this claim.There were issue with older GPSr, but I have never heard of the tree leaf problem with a 12 channel.
In none of my post did I say GPS reception is not effected by trees, what I have been saying is that an external antenna is not needed for geocaching.Nor did anybody claim that GPSr "lose" reception because of leaves in trees. Performance is degraded and can be improved with an external antenna.
The Delorme link works for me this morning. It's a .pdf file.
Garmin and any other company selling a product will say anything they can get away with to promote sales of that product.
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Not all trees lose their leaves and I have never seen any scientific study to back up this claim that GPSr lose reception because of leaves in trees. Can you provide a link to any study that has been done to prove this claim.
There were issue with older GPSr, but I have never heard of the tree leaf problem with a 12 channel.
While you may be a good salesman, you clearly have little understanding of the technical aspects of the GPS. My experience is 29 years as a Marine Electronics Technician having repaired/maintained/installed many types of GPS receivers since the first marine units came out and the Navy's Transit Satellite system receivers before that. But you can't be swayed as your one of those guys whos receiver ALWAYS gets you within 5-15 feet of a cache and your receiver ALWAYS maintains good satellite lock no matter what. Probably even works in the trunk.
http://www.fs.fed.us/database/gps/mtdc/map...smap_76_rev.pdf
http://www.waypnt.com/html/hgg24.html
http://www.fs.fed.us/database/gps/mtdc/gps.../Nav_3-2001.htm
http://www.digitalgrove.net/bolstad_gps_comparisons.htm
http://www.digitalgrove.net/GPS.htm#external
http://www.delorme.com/support/postpro/GPS...ion_Methods.pdf
http://www.gpstom.de/GPS/gar-wood.htm
Even Garmin states that tree cover can block GPS signals.
And you don't need a scientific study to prove the difference. Just walk into the forest, take note of the number of sat's you are receiving and their signal strength and then plug in the external antenna and watch the signal strengths rise and the number of sat's increase.
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As far as the antenna issue, if your are looking for a cache in an area in which and you cannot get a lock, there is a very good chance you are in the place anyway. A person needs to be locked onto the satellite to hide a cache and sense very few cachers use external antennas the external antenna just is not going to be very useful, the odds are the person did not have one so why would anyone need one to find a cache, They do not need one.
You forget about all the hundreds of caches being hidden during the late fall, winter and early spring in much of the country while there are no leaves on the trees. The external antenna will be a plus when searching for these caches in the summer under dense foilage.
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For instance, there are many, many caches hidden in the Patapsaco Valley State Park system that runs through a large area of my state. (Maryland) The problem is, there are dozens of entrances to this park system within 10 miles of my workplace. Many (or most) of these are not marked on a map and roads that appear to be close to the cache are not usually close to a park entrance.
I have done a few caches in this park as well. They have a nice web site with maps and directions to each of the entrance area's. They even have some nice topo maps with all the trail systems that you can purchase for just a few bucks. Well worth it if you hike often there. I provide directions to parking for my cache but it doesn't bother me that there are none for caches that I'm seeking. Just part of the fun trying to figure out the best spot as far as I'm concerned.
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It should be remembered, however, that these external antennas are powered by the GPSr. This severely limits your battery life. This isn't a problem in the Jeep because my 3+ is on external power. On trail, however, I'd rather not have to keep changing batteries.
These antenna's typically draw less than 10ma of current. In fact, the Gilsson is rated at 7ma. Compared to the 125ma that my Map76 uses, that is very little and certainly isn't a severe load.
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The OP never asked if he "needed" an external antenna. He just wanted to know if it would help with locking on and staying locked on to the signals. The answer is of course, yes, under certain conditions. JV, you are the only one hung up on this issue of need. Do you need your GPSr to Geocache? No, some people geocache without one at all. Do I need my $400 Garmin unit? No, I could get by with a cheap Gecko model. Do I need my external antenna? No, but it sure is convenient and helps with reception under tree cover. As far as fantasy, to say that your GPSr always gets you within 5-15 feet 90% of the time, well that's fantasy!
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I use one all the time. It fits neatly under my hat and so I don't have to worry about holding the receiver in the proper orientation all the time and I have found that it makes a big difference in reception under tree cover. It's a fact. Under marginal conditions, you can plug the antenna in and see a significant improvement. A friend of mine at work who just started geocaching bought one for his Garmin 60C and he was just amazed at the difference it made while trying to use the receiver indoors. Without it, he could get 2-3 sat's but it would never lock on. He then connected the antenna and within 20 seconds he had lock on 6 sat's. The Gilsson antenna for $20 is a great buy.
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I'm with clearpath, that's exactly what I was thinking.
The Great Outdoors!!!
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Position is determined by the time it takes for the signals to go from the satellites to the antenna. It takes at least 4 signals to get an ACCURATE fix. The time it takes for the signals from each satellite to travel from the antenna to the receiver is the same and therefore the x,y fix will be the location of the antenna without any additional error due to cable length. The elevation result will have some error due to cable length but the error depends on the angle of the sat's used for the fix and isn't just simply the length of the cable or length times velocity factor of the cable.
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The antenna shown is an active type. It is a few years old. All the marine antenna's Iv'e seen in the last couple years are of the patch type. Some passive (can be used with up to 25' coax) but most are of the active type.
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Here's the pic of a quad-helix antenna for a Northstar Marine GPSr. These antenna's typically come with 30' of cable and a larger antenna (high gain) is required to overcome the losses in the cable run.
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I use the i.Trek bluetooth GPSr. It will run up to 20 hours at full operation and even comes with an extra battery free. Fits neatly under my hat. No hassle with cables or reception problems while hiking to the cache area.
Oops. Looks like the extra battery isn't included free anymore. But you'll never need it anyway.
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The Geocaching.com membership has increased by over 3,000 new members in the last week alone!
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I would say this is not true, For an antenna to work properly it is made to be the same wave length as the signal it is receiving, A patch antenna is a piece of metal that is stamped out so that the area of the antenna is electrically the same size as the wave length of the signal from the GPS. This cannot really be changed without having and adverse effect on the GPS receiver.
While antenna size is a function of the frequency used, it does not restrict it to "a wavelength" in size. There are many ways to make an antenna "resonant". This is done by varying the physical size as well as the electrical size with other components. I'll have to bring my camera in tomorrow and show you guys a pic of a quad-helix gps antenna that is as big as your whole receiver. Making an antenna of multiple 1/2 wavelengths (the basic starting point in antenna design) in size is the most common way of increasing an antenna's gain.
Garmin Basic Etrex Version 3.0
in GPS technology and devices
Posted
Garmin has finally posted the manual for the "new" basic eTrex model with version 3.0 firmware.