Phoenix2001

Have a look at: http://www.geocaching.com/seek/cache_detai...KJ&Submit6=Find

Any GPSR with a map screen that will zoom in to about 2 to 4 feet per pixel. I currently use a Garmin GPSmap 76.

Did you make a note of where the satellites were? Sky blockage of 60 percent could be at problem if you were there when there weren't many satellites overhead. The distribution of satellites varies and sometimes one is taken out of service for maintenance for a day and sometimes more days on unknown failures. See: http://www.gpsmap.net/SatellitePatterns.html If you can find another cacher with an old or new eTrex that works well, it might help if you can compare yours to theirs to see if yours is working correctly.

In terms of specifications from Garmin - no. One indication that only one antenna is used is if I plug an external antenna into the GPSmap 76 and then block the external antenna - all the signal bars go to zero until I either remove my hand or disconnect the external antenna. I don't have a passive antenna to do more tests. Check the following message in sci.geo.satellite-nav or do a google search in that group for "external antenna current" or some such. This was with a 12XL but I doubt they changed much. <http://groups.google.com/groups?selm=5doj82%24qpi%40harpo.cs.ubc.ca&output=gplain> Would you share what these are? Yes, 9' wouldn't make much of a difference. I think the error in the system is larger. The thing is, if I'm designing a system to use two antennas - what is the goal. I don't necessarily know whether the antennas are close together or far apart. I could compute the location of one and then the other and compare. Then what? Note that combining the signals from the two antennas is not necessarily easy. The best solution might require two signal processing units and then compare the output from one with the output from the other. And perhaps in essence end up with an average of the location of antenna A and antenna B. Instead of the extra expense of making a "dual antenna" receiver why not just put the single antenna receiver at location A and mark then at location B and mark and average? In other words I see engineering challenges, more costs, maybe not much in the way of benefits so I wouldn't expect it to work that way. Not taken that way and I don't mean too either. I read to learn and help if/when I can and it's OK with me to disagree. Thanks, Dan

Ahhhh, you didn't know you were supposed to read a GPS 76 manual?!?!? Garmin manuals have plenty of room for improvement. It looks like they didn't say anything about how to hold the receiver in the 60C, 60CS, 76C, and 76CS manuals. My Venture manual on one page says, "Hold the unit.... with the antenna pointing up." It doesn't say which direction is "pointing up". In this case the eTrex series have patch antennas that should be horizontal which is the same plane as the screen. In other words the eTrex models should be held horizontal (then the antenna is pointing up) but are also not that sensitive to orientation. I can turn the Venture upside down and have it still work. The 76 series (76, map76, and 76S) have quadrifilar helix (sometimes referred to as quad-helix or just helix) antennas, as do the 60 series and 76C and 76CS. These antennas are sensitive to orientation. If you read a GPSmap 76 manual it will tell you to hold it in front of you "with the top of the unit pointed toward the sky." This puts the screen in a vertical direction - not the way you would usually put a map.

I've assumed you are using it correctly.... That model needs to be held vertically for best reception. It won't do well if you hold it horizontally, which you have to do for the magnetic compass to work well (If Garmin is still using the hardware that's in the 76S).

I wasn't aware of this; I have checked the manuals for both the 76CS and the 60CS and find no mention of it. It was my understanding that even with an external AE plugged in, the unit still used input from it's built-in AE. Trying to use two antennas at the same time would be something like my putting headphones on you and feeding one person talking into one ear and delayed by a fraction of a second into the other ear. Better example.... The position that is calculated is where the signals "come together" i.e. at the antenna. If the external antenna is put 200 ft. away and the receiver tried to used both, it would be trying to calculate the position of both antennas at the same time. When using a re-radiating antenna with a GPS receiver it's important to make sure the internal antenna can't receive the signals directly from the satellites and only from the re-radiating wire. I did mention that an amplified external antenna can help when vegetation attenuates the signals. My primary use is mapping trails. I use a GPSmap 76 in my hand with it's internal antenna and a GPS 76 in a belt holster connected to an external antenna on top of my hat. Sometimes one does better, sometimes the other.

The receiver might not be operating "within spec" and should be sent to Garmin for repair. Try using it more in fairly clear areas. If you continue to have trouble note how often so you have some good statistics to give to Garmin's technical support.

Another thing that might help is to use some satellite prediction software or just pay attention to the satellite patterns on your GPSR screen. If you are going into an area where the satellites are going to be blocked from the horizon to a fairly high elevation (angle), go there when you will have a good distribution of satellites high overhead. A straight line is a very poor pattern. The patterns repeat about 4 minutes earlier each day (sometimes a satellite will be down for a day for maintenance or other reason). Sometimes there are few satellites overhead and many close to the horizon. This is not a good time to go into a wooded canyon. The distribution of satellites is not the same throughout the day.

There is a "GPS Units and Software" forum that's a good place for hardware questions. The 60CS has an MCX antenna connector. An external antenna plugged into it draws power from the 60CS and causes the 60CS to switch from the internal antenna to the external antenna. The newer Garmin receivers supply 2.5 volts via the antenna connection if they have an external antenna connection. Make sure you get an external antenna with the appropriate connector (MCX) and operating voltage range. Some antennas that are specified to work from 3 to 5 or more volts will work at 2.5V. eBay can be a good source for external antennas. A Gilsson antenna from GPSgeeks is a common one purchased. The early Garmin eTrex series (I don't know about the new color models) did NOT have an external antenna connector. You need to use a re-radiating antenna with them and the re-radiating antenna needs a power supply - it doesn't have a physical connection to the receiver's batteries. The 60CS has a pretty good antenna. The external antenna may not make a big difference. If you are blocking signals often with your body, the external antenna will help if you mount it on top of a hat, etc. If vegetation is attenuating the signals, it might help enough. If buildings and mountains are blocking the signals no amplifier will work because there aren't any signals to amplify. Amplifying signals bounced off a wall, rocks, or refracted through leaves is also not good (multipath). In other words an external antenna will help in some conditions but not always.

I've never used the compass screen to navigate to a cache. And so far I haven't used my real compass either. I use the map screen and just keep going until "my location icon" is on top of the cache icon or I can see that the cache is say "25 ft. ahead of me" if the terrain is not walkable. Then I have the approximate center of the "search circle". How easy it is to use the map screen depends on the size of the icons used to indicate your position and the location of the cache and how far you can zoom in. I usually have the map screen set to track up and track log on. Showing the track log on the screen as I approach the cache helps with the orientation of the map. Then I've sometimes left the track logging on so I can see where I've walked in relation to the cache indication but not for long. The pack and GPSR is soon set down and the real search started.

If your receiver generates coordinates that are clearly wrong for a few minutes it might help to stop the receiver by putting the unit into simulate mode and then back on again so it will re-search for satellites. If that doesn't get it back to the correct location then try turning it off and back on again. It might be best to leave it alone, like you did, if you have a heavy enough canopy and/or a poor satellite constellation because the receiver might not be able to regain a lock. On five occasions last year I had a Garmin GPSmap 76 start generating weird position values. At worst I got it back to normal by turning it off and back on. One of the times may have been caused by multipath off of high mineral content rocks above timberline in the Colorado Rockies - trees aren't the only things that can cause trouble.

You might consider how easy it is to break the item. Something that's easily broken might go into the cache in one piece but not stay that way.

Note that large-scale maps cover a small area not a large area. The scale is an inverse relationship. I wouldn't put much emphasis on how easy the cache is rated. You might be able to find a "5" cache easier than a "1" cache when just using a map. If I put an ammo can by a cactus in the middle of a desert that's flat for miles and no features that would be shown on a map, you could find it easily with a GPSR but a map and compass probably won't get you close. Try looking for caches that are near easily distinguished features on the map. In other words you can "see" where the cache is located relative to features shown on the map and in the field. You're going to "triangulate" your position and the cache location with the features - as tirediron said "basic skills with map & compass".

Currently there's no software that does everything I would like it to in terms of handling a GPS receiver and annotating maps. If you are interested in marking trails with dotted or dashed lines there is a version of GPSUtility that will do that and save as a BMP image (tracks merged with background map). It hasn't been released to the public so you would need to contact the author. Some other programs might do what you need such as GPS Trackmaker and are free. See software list at: www.gpsmap.net/links.html

I started with a Garmin 38 when it first came out and no longer have it. Then got a 12XL followed by a hardware upgrade to it. I still have the 12XL and added a Venture in Aug. 2001. Picked up a GPS 76 in Dec. 2001 and added a GPSmap 76 in Dec. 2002. (I use two receivers to help with accuracy mapping trails). I keep the Venture as a backup and for use on bike handlebars. I'm waiting for a higher res. and slightly larger color screen in a 76C version.

Good observations. In general short term averaging (minutes) doesn't really help when the conditions are good. If the conditions are bad, some averaging can help. General comments..... If you're trying to mark the location of your cache, try walking away at least 50 yards/meters and back and in different directions. Note the readings you get at the cache. If you have good conditions the readings will be close, if you have bad conditions the readings will probably vary a fair amount in which case you might average them. Best is to try to get multiple marks at different times (different satellite constellations with good dispersion) on different days. Note that you get the same satellite constellation 4 minutes earlier each day. Don't take a reading when a major solar storm hits unless you are using DGPS processing (ie WAAS) to get the correct ionosphere delays. The USFS tests at the Clackamas site have some good info.... http://www.fs.fed.us/database/gps/gpsusfs.htm http://users.erols.com/dlwilson/gps.htm http://www.gpsnuts.com/myGPS/GPS/Technical...curacy_by_c.htm

Garmin receivers do not have auto averaging, Magellan receivers have auto averaging. The Garmin original eTrex series does not have any waypoint averaging but other Garmin receivers (12XL, 76 series, the new Legend C/Vista C, 60C) have a user command to average.

I guess you're not in the Colorado Springs area. I count more than 40 MOC's within about 22 miles of 80904. A few of those who place many caches around here make them MO. (This isn't a complaint.)

The antenna on all the 76 series receivers "sticks out" too. It's just that the case covering the antenna is as wide as the rest of the body to create an air pocket to help it float. The antenna is also centered above the circuit board on the 76 series (C's or not) and above the left side of the circuit board on the 60's - a minor difference. Microwaves don't care about the shape of the plastic case. Most of the hardware of the 60 and 76C's is the same (outside of different size memory chips, circuit boards for the different keyboard positions, etc.). So they will probably perform about the same and if they are "tuned" the same. I have been using a GPS 76 and a GPSmap 76 (at least one year newer than the plain 76) for more than a year simultaneously (for mapping purposes). Sometimes one will pick up faster and sometimes the other so beware of jumping to conclusions.

Then "Bloodhound" should get the credit for the find. Take along an ink pad so he can "sign" the log with his paw.

I think the social trail created after a cache has been placed also spoils the hunt. A "line drawn in the dirt" right up to the cache is a giveaway.

Not essential but some items to consider... A pencil instead of a pen in cold weather in case you can't keep the pen warm enough to work. Something to sharpen the pencils with - especially the dull or broken pencils in a cache. Some kind of marking pen that will write on wet log book paper.

That's fine. If that's the way you think it it should be, then I give you permission to log a find for this cache. I mean it's in the US and you live in the US, so why not. You've probably even flown over it once or twice if you've ever visited the east coast. Thanks Brian, it's logged No thanks. For me I didn't find the cache unless I opened the container. I regard signing the log as proof I was there. If the container was a type of puzzle to solve to open, it would certainly be part of the challenge so I would not log a find until I got it open. I wonder if those that are so inclined to add to their find count avoid multi-caches. I'm working on a puzzle multi-cache. I have to find 10 metal tags before getting to the final cache. That's 11 finds to get credit for one find. That's a lot of work for a count of one but then I'm enjoying the journey and not in it for the count.

It would help if the size attributes had different first letters for abbreviations. So I would also suggest “Small” instead of “Mini”. So there would be M, S, R, and L, instead of M, M, R, and L.