Forum: Just Getting Started In Geocaching
Topic: Types of Antennas???
started by: ILBCNU
Posted by ILBCNU on Nov. 14 2003,6:04 amI am "almost" ready to update my classic Magellan Pioneer GPS and I am totally confused as to the types of antennas. I do a lot of walking in the woods and I heard a GPS with a Quadfilar Helix antenna is what I need. The problem is, I can hardly believe that a company as good as Garmin would be selling most of their GPS's with the traditional internal antenna if it was inferior. Has anyone used both types in the woods or does anyone have experience using both types Your assistance would be greatly appreciated.
Posted by DustyJacket on Nov. 14 2003,8:04 amI have not used both, but I have been repeatedly told that the Garmin patch antenna is best in looking for satellite more "above" you, and the Magellan quadrafiliar antenna is best looking for satellites closer to the horizon.
Some say the patch antenna is less effective in dense tree cover.
I use a Magellan and have excellent results, but if I was in canyons and such a lot, I might look at a Garmin.
BTW - the Garmin V has a quadrafiliar - it comes highly recommended for driving and geocaching, but it is pricey.
Posted by PC Medic on Nov. 14 2003,8:10 amIMHO (and many others), Quadfilar Helix antenna is definitely the way to go. My experience is that you get a better more consistant lock on the Sats with this type. This is one reason I am am a big fan of the Magellan Meridian Series (having had a Meri Green, a Gold, Platinum and now a Color). I am in Virginia and a lot of heavy tree cover in the area, yet I get a fast and consistant lock every time.
Posted by welch on Nov. 14 2003,8:48 amIve only used an etrex, which has the interal *patch* antenna. It's worked fine for me (make sure you have it facing skyward as often as possiable ), except under very dense cover.
I also like the fact the etrex is pretty small, but the trade off is it has a smaller screen than some other units.
Posted by team_tar on Nov. 14 2003,12:07 pmThis is a sort of everlasting debate. To my knowledge, is definitively true that quad helix are somewhat
more sensitive. This may depend on the antenna type, or on the "equivalent area" of it: a HUGE patch
would be surely more sensitive than a small quad helix... but, shortly, it's almost sure that eTrexes are
somewhat less sensitive in dense cover than their quad helix competitors, Magellan sportrack/meridian,
Garmin GPS III / V...
The debate is wether this difference is significant or not, practically. This forum seems to me to be
rather "Magellan oriented", conversely on GC.com (when the forum will rise again from its ashes :rock: ...
my impression is that the Garmin fans (or users), mainly eTrex users, are the majority.
They seem to place and find caches without major problems, so...
I always used eTrex (the "yellow submarine", and now since a month a Legend). In my "type" of woods (timber forests in the Alps, northern Italy) it always worked
well. Signal loss happened but only in sporadic cases. It never became an issue. Never
had the impression that I couldn't trust the "yellow submarine". Would a Helix perform better
in the same situation? Likely. SIGNIFICANTLY better? I never had significant problems, so would be
tempted to say no, at least for me.
I would say: consider the "antenna factor" in the purchase, but together with many others.
Don't think that a patch would be a MAJOR shortcoming...
The eTrex Legend/Vista are powerful GPS units.
Posted by PC Medic on Nov. 14 2003,12:33 pmHmmm...Pro Magellan, not I. I liked my little yellow eTrex also. But as you say, Quad Helix over patch in dense cover is a plus and while I would also love a Garmin V, I just happen to have Magellans instead (for the moment )
Like Welch pointed out, if a patch keep it pointed skyward as you tend to get better reception that way due to placement.
Posted by team_tar on Nov. 14 2003,2:34 pm
Well... this is something that I never considered before... how much of the perceived sensitivity of the patches comes from "position" issues.
I mean: for what I know, helix are not so sensitive to orientation, by keeping them horizontal you lose only few sensitivity (correct me if I'm wrong).
Patches are EXTREMELY sensitive to orientation, an eTrex will lose almost all its reception if held vertically. It can become difficult to have a lock also in the clear. Is possible that some people ignore this? It seems strange to me.
I always assumed that people was comparing the receivers held in the RIGHT position (vertical for helix, horizontal for patch)...
Of course, you may consider this a minus of the patches: on a hike, for example, you have to find out a way to keep them near to horizontal,
which can be a bit tricky or annoying.
My Legend has his Garmin case with the belt clip clipped on the backpack strap exactly over the shoulder, with the antenna pointing outwards... nothing very original, but it works quite well.
Posted by Quinn on Nov. 14 2003,2:42 pmAll I can say is what the facts were shown to me. I tested just about every unit placed in my lap by both magellan and also garmin. I found repeatedly that the Garmin units with the exception of the IIIPlus and the Garmin V just could not perform anywheres as well as the Magellans.
I had the Vista and it was at that time very pricey, I also had the Garmin map76 which also cost quite a bit. Now i can easily go out and buy Magellan units for far less that perform quite a bit better in any conditions.
Now like I stated...you see quite a bit of Magellan here only because of the quality and nothing else, but I also know a good thing when i see it thus the reason why I use the Garmin V
Posted by Volvo Man on Nov. 17 2003,5:26 pmI agree on the quad helix, I've found that it doesn't seem to matter what the orientation, the Magellan is very accurate. I get consistent results and lock even when the unit is in my hand, swinging back and forth on the trail, or when it's tucked in it's pouch.
In my van, I have to have it up on the dash as there is a huge ammount of metal behind and above the cab, what with the ladder rack and stuff. but in most cars/suvs I've used it in, I can prop it up in the centre console and get good results. In my 87 jaguar, there is a little shelf on the centre dash, with a lip above that is about level with the top of the windshield, and signal strength is quite adequate with the magellan on this shelf.
I'm currently using a gold, this was my first purchase of a GPS and to echo quinn, I chose it based on the features and build quality for the price. On my christmas list (probably not this year ) is a platinum.
I would imagine that having to keep the GPSr horizontal would be a real pain for auto navigation too.
Posted by Renegade Knight on Nov. 30 2003,9:37 amI've seen a forest service study that contradicts what Quinn has seen however it was back in the GPS III days and things have come a ways since.
Since I've seen both the patch in the etrex, the Quad in the Sport track and the GPS-V and here are my real world observations.
1) The patch is noticeably better near vertical surfaces such as rock canyons and buildings. The Quad in my V had problems.
2) The Quad is noticeably better under tree cover.
Noticeably better meant move over 3 paces and re-gain your lock. In other words not enough to be a deal breaker on either GPS.
Insofar as the V quad and the Magellan Sport Track Quad there is no noticeable difference. I found that my Garmin is happy to tell me it lost lock while the Magellan would keep on doing its moving average thing without a lock and not tell you. Both just had a different software means of dealing with a lost signal but both lost the signal in the same locations as we were caching. As far as the moving average thing I've seen advantages to both the instant location and the moving average location depending on what you were doing and where you were at.
Posted by Tahosa on Dec. 08 2003,6:24 amI've used the Vista quite extensively in CO tracking trails for the USFS and the only place I've encountered any problems is in a few narrow canyons.
I usually carry it under my left shoulder strap with the antena facing up, and when I take a break I just lay it on my hat on the ground.
So for me its never been an issue its always performed quite well.
Posted by Northern Lights on Jan. 06 2004,4:12 pm
All are very good points..... I think the final decision is how you will be using the unit. Me, I cant stand the little buttons on the side of the e-trex units. I like the buttons on the front where I can see them and push them while traveling in my boat, or car, or even walking. I've used and owned Garmin, and now I own and use Magellan. I think the quad antenna is better in dense forests like I enjoy in northern Michigan, so I got a Magellan Gold, than way I can put a SD chip in it and download all kinds of maps....wow, is it ever slick!