Garmin Forerunner Series and Whites Coverage

[DougPaul]

Not what I would expect from a device that's a receiver, not a broadcaster. Why is this?

* Antennas that are within a few wavelengths of each other can distort their patterns (gain vs angle of arrival of the radio wave). The wavelenth of GPS signals is 19cm.
* Close antennas can strongly couple signals between each other.
* A GPS receiver is not an intentional transmitter, but it uses a number of radio frequencies internally all of which leak to some degree--every wire is an antenna. (Some of this leakage is very detectable in some of the older Garmin models near 148MHz, don't know about the newer ones.) These leaking signals can potentially interfere with other GPS receivers (or aircraft avionics...). It may not take much power to cause interference--standard radio receivers can detect signals of less than a millionth-millionth of a watt and GPS signals are even weaker.

Doug

 

[Remix]

I have used the 201 and 301 and they both had very poor sensitivity in the woods, but were adequate for biking...they need to face the sky at all times.


For a cheap bike mount for any accessory with a strap, consider some pipe insulation from Home Depot or your neighborhood hardware store.

 

[IndianChris]

FWIW...there was an article in the NY Times on 12/20 (yesterday) about the accuracy of GPS units used by runners, joggers, walkers, bikers, etc...
Sounds like they're not too accurate...
Here's the link.

 

[sardog1]

* A GPS receiver is not an intentional transmitter, but it uses a number of radio frequencies internally all of which leak to some degree--every wire is an antenna. (Some of this leakage is very detectable in some of the older Garmin models near 148MHz, don't know about the newer ones.) These leaking signals can potentially interfere with other GPS receivers (or aircraft avionics...). It may not take much power to cause interference--standard radio receivers can detect signals of less than a millionth-millionth of a watt and GPS signals are even weaker.

And there's an even bigger potential issue in the reverse direction (yes, I just had to use that pun!): LightSquared and GPS.

 

[Snowflea]

My watch might record my run as, say, six miles, but according to Google Maps, the actual distance was more like 6.5 miles. That kind of discrepancy, of course, plays havoc with your training. The pace calculated by the watch is much too slow, and the run becomes an exercise in frustration.

Really? Havoc? This statement sort of cracked me up.

From dictionary.com:
Havoc: great destruction or devastation; ruinous damage.

Maybe it's because I'm just not that much of a 'numbers person' -- I don't weigh myself either -- but methinks the author is taking his running way too seriously.

 

[DougPaul]

And there's an even bigger potential issue in the reverse direction (yes, I just had to use that pun!): LightSquared and GPS.

Yeah--LightSquared has been threatening GPS for a while now. Tests show that they will cause widespread interference to GPSRs if allowed to operate: http://www.gpsworld.com/gnss-system...erference-with-75-percent-gps-receivers-12418. There are a number of organizations trying to get their provisional permission firmly revoked.

Doug