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Polar HRM problems under power lines, anyone?(10 posts)

Polar HRM problems under power lines, anyone?gmc
Aug 23, 2001 5:11 PM
When I ride a local bike trail my heart rate monitor (Polar A5, 3 months old so batteries are pretty fresh) craps out - reads "00" - for the duration of the trail. I've had intermittent problems with the thing over the summer, like it telling me my average HR for a two hour ride was 225 (am I a hummingbird?). But nothing like this. Then I figured out that above the trail are some power lines. Lots of them actually, as this trail is an old railroad right-of-way.

The engineer in me says this seems a little odd. I wouln't have thought there was a strong enough field to screw things up, but...? HRM starts working immediately off the path.

Anyone else have this problem? At first I thought I must be crazy, but three straight rides in the same location seem to indicate I'm not. About this, anyway.
Mine goes wacky too.Atombomber
Aug 23, 2001 5:35 PM
Even the fenceless dog retaining systems screw my HRM up.
re: Polar HRM problems under power lines, anyone?Lone Gunman
Aug 23, 2001 5:37 PM
Not just the Polar either. I have a spot on one of my regular routes that the monitor craps out for about 1/4 mile or so.
Not Just PolarRich Clark
Aug 23, 2001 6:35 PM
My Cardiosport zeroes out under power lines, too. Part of my commute follows a trolley line, and the HRM reliably zeroes the entire length of it.

It's a common failing of these things, I understand.

Yes, indeed.dough
Aug 23, 2001 7:06 PM
The Leadville Trail 100 MTB race course goes up a nasty climb right under some big power lines. LT100 racers refer to this section simply as "The Powerline". My Polar HRM craps out and reads "00" everytime I that section.
Aha, so I'm not crazy. Thanks all (nm).gmc
Aug 24, 2001 2:29 AM
re: Polar HRM problems under power lines, anyone?DoothaBartman
Aug 24, 2001 6:24 AM
I've have two polar HRM's, and both have the same problems. My newer polar is coded, so it happens less, but every now and then my heart rate will read 246 for a mile or so. I know this sounds odd, but I've found the problem doesn't manifest itself in the early morning hours when the sunlight is weak. Later in the day when the sun is blaring I'll have trouble. Also, sometimes I'll ride the breakdown lane of a state highway and the route itself won't seem to give any trouble at any time of day, regardless of powerlines, but it seems passing cars (especially 18 wheelers) will send it into a spasm. I never have trouble on the mountain bike trail.
Here's another weird one for ya.dough
Aug 24, 2001 2:26 PM
My HRM sometimes goes on the blink if I have it on while driving my truck. No, I don't care what my heart rate is while driving. I discovered this by accident. I sometimes forget to take off the chest strap after a workout and while driving home I notice it doesn't always work.
Come on, did you read the manual?Trollman
Aug 24, 2001 8:25 AM
If you read the manual you would have come across the part that deals with interference from electrical sources. I believe it even lists automobiles as possible culprits in this area.

You would know if your heart was beating at an average of 225 for 2 hours.

Of course it was interference. Do you need us to tell you this?

Next time read the whole book.
Not from O/H's on walkerszelig
Aug 24, 2001 10:30 AM
I don't get it from power lines hung on the big steel walkers but I do get interference from power lines underground or on overpasses crossing a train line with o/h power. EMI drops off pretty rapidly as a function of distance although microwave signals are supposed to also affect the receiver. I have O/H power lines on my property through an easement and have never had a problem. Well, there're the horns on my head, but other than that. In my 2.5 year absence they added a telco transponder on the very walker sitting on my property so we shall see what effect that has on my heart monitor and my trick stereo system.