Dumb Question

[polar69]

Right ! Why does my etrex still work even if its inside my jacket pocket

 

I thought it needed a clear view of the sky

 

( see I said it was dumb _)

[+Sparky-Watts]

Right ! Why does my etrex still work even if its inside my jacket pocket

 

I thought it needed a clear view of the sky

 

( see I said it was dumb _)

Not a dumb question...a very interesting one....being a big Garmin fan, I'd say because you bought the best brand available...but, being the un-opinionated person that I am, I'd have to ask, what kind of jacket material, is the pocket totally closed, how long will it work that way, etc......I may have to try that with my Legend.

[polar69]

Its round my neck on its lanyard, jacket is of the quilted variety

[+bons]

Why does my etrex still work even if its inside my jacket pocket

 

It's the same reason that the signal penetrates the plastic around the antenna...

 

The signal can penetrate light cover. The more things blocking it, the thicker they are, and the more metallic they are, the less chance the signals will get through.

Edited April 1, 2004 by bons

[putawaywet]

My Magellan 310 and Meridian Marine both work in the cab of my truck as well as the cabin of a boat.

'go figure'

[+Sparky-Watts]

Well, now that it's springtime, and I don't wear jackets anymore, this is disturbing.....I'm still gonna try it out today, though. Maybe gain some good information for next winter!

[polar69]

Its always winter in Yorkshire !

 

I shall experiment with different materials

 

Where's that wetsuit

[+briansnat]

My eTrex Vista also gets reception in my jacket or pants pocket as long as it's facing the right way. I even get reception sometimes on my dining room table and my house doesn't exactly have a lot of windows.

[Mushtang]

The GPS receiver gets information from the satellites by way of electromagnetic radiation, much the same way as your radio gets information from your local radio station. The main difference is that a radio station may transmit it's signal at a very powerful 100,000 Watts, and the GPS satellites only transmit at a weak 30 Watts.

 

That weak signal can be blocked easily by tree cover, tall buildings, stuff in your backpack if you toss it in there, or even your hand (hold your hand over the antenna and you'll lose Sat Lock).

 

So, your jacket probably isn't thick enough to totally block the signal from the satellites. It's more likely that if you had on a much thicker coat you'd lose reception.

[+wimseyguy]

Why does my etrex still work even if its inside my jacket pocket

 

It's the same reason that the signal penetrates the plastic around the antenna...

 

The signal can penetrate light cover. The more things blocking it, the thicker they are, and the more metallic they are, the less chance the signals will get through.

Guess it's time to hang up the matching tin foil beanie and jacket combo.

[+wimseyguy]

Right ! Why does my etrex still work even if its inside my jacket pocket

 

I thought it needed a clear view of the sky

 

( see I said it was dumb _)

Blue, no red...arrrrhhhhhhhhh

Sorry, couldn't resist a request for stupid answers.

[+fly46]

The gps I use loses it's signal if I let it hang around my neck without me holding it up.

[+JeepCachr]

Right ! Why does my etrex still work even if its inside my jacket pocket

 

I thought it needed a clear view of the sky

 

( see I said it was dumb _)

Its not working, you just think its working. If you could get in your pocket with it you would realize its not working. Its just guessing where its at while its in your pocket.

[+Renegade Knight]

It's a function of the type of material that blocks the GPS signal. Different radio waves have different properties. You can listen to the radio in your house through walls. Some metal framed buildings block the signal as do bridges.

 

Your GPS signal is blocked by water. Your body, tree cover etc. are 90% water and so they block the signal very well. Your shirt pocket or a car window doesnt'.

 

Some cars have a thin metalic film in the front window (my Pontiac Montana has this) and that will block signals as well.

 

Your radio will work in your house but your GPS will have a much tougher time of it but some will get a signal indoors.

[Pipanella]

Its not working, you just think its working. If you could get in your pocket with it you would realize its not working. Its just guessing where its at while its in your pocket.

ROFLMBO!!!!!!!!!!!!!

[CHTH]

Gee I have a vista and if its not hanging with the face towards the sky I have trouble keeping a signal.

chth

[+jjdubs]

The young lady who sold me my Magellan Sportrak Map at Best Buy told me it wouldn't work in my car. I took a chance and bought it anyway. Why would Magellan sell a car lighter power adapter for it if it didn't? I'm happy to say it works fine in my car. I have it mounted on my dash. -- JJDubs

[+Shanediver]

My Legend has always worked just fine in my car. I have it resting right on the dash for trips. It even works pretty well sitting on my lap. It is off and on if I have it in a jacket or something.

[+Bill D (wwh)]

When I've finished with my GPSr for the day I often leave it on to run down the rechargeable batteries. I put it into its case and put it in the glove box of my car. When I get home I sometimes find it's got a complete track of the journey. But when I need it under trees it can't get a signal...

[Mushtang]

Your GPS signal is blocked by water. Your body, tree cover etc. are 90% water and so they block the signal very well. Your shirt pocket or a car window doesnt'.

See, now I can't believe this is true at all. Why would water keep the GPS signal from reaching the GPSr? It doesn't make any sense.

 

The fact that my GPSr works just fine in my car while it's raining tells me otherwise. I think the next time I'm near a clean stream of water I'm going to set my GPSr in it and see if it loses Sat Lock, then I'll know for sure.

[+Joe Smith]

one of the most accurate waypoints I have ever taken was sitting in my bathroom. it's in the middle of the house with no windows. I guess the roof and insulation didn't stop the signal so I don't think a jacket would, as long as you hold it right.

[+bons]

See, now I can't believe this is true at all. Why would water keep the GPS signal from reaching the GPSr?

Actually water is very good at blocking radio waves. The higher the frequency the more water blocks it. If you're running a wireless system in your house and you have a pocket PC running Kismet take a walk behind the water heater and watch your signal drop dead.

[+captnemo]

one of the most accurate waypoints I have ever taken was sitting in my bathroom. it's in the middle of the house with no windows. I guess the roof and insulation didn't stop the signal so I don't think a jacket would, as long as you hold it right.

 

Just wondering why you need a waypoint for your bathroom? Is it that hard to find?

 

My GPS V works in any of my vehicles including my Motor Home. It has no problems inside my house. So go figure?

[+GeckoGeek]

The young lady who sold me my Magellan Sportrak Map at Best Buy told me it wouldn't work in my car.

Metal will block the signal. Normal glass won't. But glass with a metal tint usually does. So the young lady wasn't completely wrong. It doesn't work in some cars.

 

What she should have said is that she couldn't guarantee that it would work in your car.

[+G-Squad]

My Map 330 works fine anywhere inside my mini-van. In my old house that had a brick front and hardi-plank on the rest of the exterior, I could get a signal anywhere in the house. But my new house with stucco all the way around? I can't get a signal lock standing right next to a window...grrrr.

[whoneedstrails]

Your Stucco house is surounded by a sheet of expanded metal. It is what the contractors apply the scratch coat to. That is in the process of applying the stucco finish. (makes everything hold). that sheet of expanded metal is just like having a giant metal fishnet around your house!

[AJK]

I can get a signal in my house, but not next to the window - metal insect screens.....

[+IVxIV]

Some cars have a metallic film in their windshields used as a sort of transparent defroster (instead of the lines seen on rear windows)

 

Apparently portable radar detectors that sit on the dashboard looking through this film won't work properly and, I would suppose a GPSr would find the material a challenge too..

 

I'm lucky, my low-tech Jeep Yj has no such windshield film, and the fibreglass hardtop doesn't seem to slow the signal much either, a perfect geo-mobile!

[+Lone Duck]

My GPS III+ actually receives the signals through the roof while in my living room with an EPE of 20 feet or less! What usually blocks the signal while outdoors is wet tree cover, your body, or that rock wall you're standing next to. (And a metal roof.)

[Holes in my Shoes]

It's funny. I have a low end etrex that works great in my car, I can even get it to work poorly in my house (if Im near the window). If I get in to even a late strand of trees however, forget it.

[+NightPilot]

When I've finished with my GPSr for the day I often leave it on to run down the rechargeable batteries.

Why would you do that, unless you're using NiCd batteries, which aren't that common any more. NiMH batteries don't like being run completely down, and doing so will greatly reduce their lives. Keep them charged as often as possible, and never run them dead.

 

And water certainly blocks GPS signals. It's very efficient at it, and just putting your hand over the antenna will cause signal loss. The signals get through rain because the raindrops are widely scattered and the extremely short wavelength signals easily travel between them.

[+Runfrog]

Why does it still work? You are extremely lucky, thats why. My Etrex Legend won't work when I hang it around my neck, coat no coat, clothes or or going natural, looses its signal. It does usually pop right back but can also take a few seconds to get the signal again. However my older 12 keeps right on going.

[+KingCamilomilo]

So let's say you are wearing your jacket and your GPS is in your pocket. If you start sweating massively, will you lose the signal?

 

Is this a dumb enough question or should I dumb it down a bit so it fits in with the forum topic?