The Great Big SPOT Thread

[SpotMaker]

Originally Posted by TomW

I haven't seen the specs. Did they specify the duty cycle? I presume 4.3 days means 103 hours of use (ten 10-hr days) at 6 transmissions per hour, or 618 GPS fixes and transmissions. Not too bad for something that size.

That is correct. Multiply 4.3 x 24 hours to get hours of operation on a set of batteries.

Originally Posted by TomW

Based on what Spotmaker's said previously about their transmitter and antenna design standards, I'm betting they're the same in both Spot 1 and Spot 2, thus you're no more likely to get through with one than the other. If you upgrade to the new Spot it'll be for the added messaging options and smaller size -- both are worthy features.

Cheers.

Transmitter radiation pattern and power is specified to a gnat's arse by Globalstar. So you're right that the transmit performance of any antenna operating on the Globalstar simplex network is going to be essentially identical (even if the antenna is physically different).

Lot's of people ask, "Why don't they just crank up the power (for better throughput)?" The reason is, it's already at the max allowed.

However, we improved the GPS performance of the antenna over that in the SPoT-I by several dB, while still meeting the very tight Globalstar transmit antenna specification. Combine that with several dB of improvement in the sensitivity of the GPS chip itself, and the GPS performance of the SPoT-II is a lot better than the old SPoT.

In Track mode, the SPoT-II transmits twice as much data as the SPoT-I (the same basic location data that the SPoT-I transmits plus redundant data that can be used to re-construct location points from messages that might be missed). This results in virtually no missed track points, but comes with a battery life impact. (The lower amp-hours of a AAAs AAs being the other battery life impacting factor.)

[boatworker]

Can anybody explain this? I have a Gen 1 SPOT and it regularly misses it's 10 minute updates while on track mode. This is my second unit as I replaced the first one for this reason thinking it was defective but now this looks like a feature of the device.

In the picture below, the line represents almost an hour between fixes. The unit was laying on the dashboard of my car up against the windshield. I was driving on the freeway and surface streets with a pretty much unobstructed view of the sky. Part of the hour the car was parked in a market parking lot again with the unit facing up to the sky with nothing around.

Any help on this would be appreciated.

[HogWild]

Originally Posted by boatworker

Can anybody explain this?

I'd guess the roof and window posts might be blocking 20%-40% of the sky. That's not "unobstructed". If the satellite it needs to see is somewhat behind you, then you're at risk of missing points. Though I've had mine inside the back of an SUV, with only side and back window views of the sky, and got better results than you in the same general area.

[boatworker]

You are correct about the roof and posts, but it is a fairly slanted windshield and the GPS satellites are pretty well spread out. With the driving I was doing the car was pointed in all directions, not just traveling one way.

The first time this happened, the unit was in my tank bag on the bike and it also quit tracking for almost an hour. Missed at least 5 ten minute check ins. Again, I was on the road not out in the woods and it had been working fine for over eight hours at that point.

[jake28]

A bit dissapointed with the customer service. I lost my Spot recently and emailed SPOT about getting a replacement because I bought no-hassle replacement insurance originally. It has been two weeks and still no emails, calls, etc.

Poo.

[boatworker]

Originally Posted by jake28

A bit dissapointed with the customer service. I lost my Spot recently and emailed SPOT about getting a replacement because I bought no-hassle replacement insurance originally. It has been two weeks and still no emails, calls, etc.

Poo.

Their customer service leaves something to be desired. When I called about the missing track updates on the first unit, the CS rep just repeated what was in the manual and on the website. This after a twenty minute wait on hold. No useful info at all. E-mailing tech support brought a quicker response, but they wanted me to pay shipping both ways and have the option to replace my three day old unit with a used one.

[DR. Rock]

Originally Posted by boatworker

You are correct about the roof and posts, but it is a fairly slanted windshield and the GPS satellites are pretty well spread out. With the driving I was doing the car was pointed in all directions, not just traveling one way.

The first time this happened, the unit was in my tank bag on the bike and it also quit tracking for almost an hour. Missed at least 5 ten minute check ins. Again, I was on the road not out in the woods and it had been working fine for over eight hours at that point.

I don't think it's the GPS satellites that are the issue, but rather the sat-phone ones for the outgoing signal that are harder to catch.

[SpotMaker]

Originally Posted by boatworker

Can anybody explain this? I have a Gen 1 SPOT and it regularly misses it's 10 minute updates while on track mode. This is my second unit as I replaced the first one for this reason thinking it was defective but now this looks like a feature of the device.

Under average real world conditions (imperfect view of the sky), due to the movement of the Globalstar satellites relative to the surface of the earth, about 70% of the messages get through.

That 70% is an average over time. Because of the way the satellites move, at any given instant, the likelihood that a message transmitted at that instant will get through may be 99.99999% or it may be 20%. However, because of this "time factor" within the equation, it works out that if you transmit three messages between 5 and 10 minutes apart, the likelihood that at least one or more of those three will get through is about 99.5%.

This is why the check-in message transmits the same data three times with a randomly dithered 5 - 10 minute interval between each of the transmissions. (And, this is why it's important to let the check-in cycle, which takes about 20 minutes, finish, for best throughput results.)

This is also why 911 (SOS) mode transmits every 5 minutes, (with a fresh GPS fix each time) until the unit is shut off (or the batteries are dead). Even if only 70% of those messages are getting through, that's 7 - 8 messages getting through per hour. So, the Geos 911 center is getting plenty of messages. Even if you're on the move in 911 mode, they are tracking you fairly accurately.

In "Track" mode, the Spot-I transmits every 10 minutes. You can expect about 70% of these messages to get through if the unit has a reasonable view of the sky. Lying on the dashboard of my Dodge Durango, this is about what I get (maybe a tiny bit better, like 75%) My boss carries his face up in a rear compartment on his Harley (transmitting through plastic/fiberglass), he gets about 70 - 75% also.

The Spot-II, when in track mode, transmits some additional redundant information between the regular track transmissions, allowing the Spot back-office to reconstruct the missed points, resulting in a map that appears to have very nearly 100% throughput. This is one of the enhancements added to Spot-II.

[boatworker]

Spotmaker, thanks for the explanation. That is the info I was hoping to get from Customer Service and Tech Support. The track feature is why I bought the SPOT in the first place so for me the added enhancement of the tracking is worth the shorter battery life.

Looks like there will be a SPOT II in my future. I guess I should have waited.

[9Dave]

Originally Posted by SpotMaker

Under average real world conditions....

That was great info.

Thanks!

[GSjoyride]

Originally Posted by GSjoyride

ok: my problem

(since I wasn't willing to wade)

batteries dead after regular use of "ok" for total of 6-8 hours. Replaced with new batteries. New batteries lasted 7-8 hours in "ok" mode. I did not engage tracking. The unit was completely turned off between uses. Successful "ok" checks that were transmitted during the "ok" period was only a couple.

Unit returned.

Major disappointment so far with the exception of the times that it did transmit (thank goodness I wasn't the guy in Mexico whose wife got the first SPOT transmit and then .........nothing, sounds like me)

UPDATE:

Spot sent to warranty department twice: for same problem, unit turning itself off and only sending 1 out of every 4 ok transmissions when it was working.

Warranty dept unable to recreate the same environment for Spot to turn off. They use a paint shaker.

I velcroed my Spot to my RAM handlebar mount so it wouldn't launch into space over bumps. Batteries had wear marks on them, compartment was powdery when opened, BOTH TIMES (as well as for battery changes, in those cases, I was thinking the reason the unit turned off was because the batteries were dead, didn't realize at the time that they last MUCH longer).

Also, when I ride, my motorbike goes in an up & down motion (not side to side unless I'm turning....), I'm mostly pavement, but I do live in California with our terrific road surfaces...so.....

THEY JUST SENT ME A NEW ONE

I won't be velcroing this one in hopes that that was the culprit...
and Matt at Spot Warranty ROCKS! he's been awesome



Cheers!

[950katoom]

Originally Posted by Roonie

I have used the Spot 1 now for three years every time I ride or snowmobile. I will definately upgrade to the Spot 2. My biggest complaint with the Spot is if it isn't pointing towards the sky and concelead in something it may not send its signal. Also if it is anywhere near your GPS it won't send either. .

How did you get a SPOT over 1 year before anyone else? SPOT only went on sale to the rest of us in Nov. 2007, less than 2 years ago!

I usually have good luck with transmissions, but every once in a while it isn't quite as reliable as other times. It is often within 4-6 inches of my GPS and that doesn't seem to affect anything. I've been surprised how many times I've looked at my SPOT page and the things is still getting signals out from my garage (no window).

[bouldergeek]

Just an FYI: I have been leaving my SPOT on every day of my 4-month Central America journey. I typically send an OK message at the end of each day. Original batteries still working well.

It sent my message from the end of the Panamericana highway in the Darien, just fine.

[SpotMaker]

Originally Posted by GSjoyride

UPDATE:

Spot sent to warranty department twice: for same problem, unit turning itself off and only sending 1 out of every 4 ok transmissions when it was working.

Warranty dept unable to recreate the same environment for Spot to turn off. They use a paint shaker.

I velcroed my Spot to my RAM handlebar mount so it wouldn't launch into space over bumps. Batteries had wear marks on them, compartment was powdery when opened, BOTH TIMES (as well as for battery changes, in those cases, I was thinking the reason the unit turned off was because the batteries were dead, didn't realize at the time that they last MUCH longer).

Also, when I ride, my motorbike goes in an up & down motion (not side to side unless I'm turning....), I'm mostly pavement, but I do live in California with our terrific road surfaces...so.....

THEY JUST SENT ME A NEW ONE

I won't be velcroing this one in hopes that that was the culprit...
and Matt at Spot Warranty ROCKS! he's been awesome



Cheers!

I actually had my eyeballs on your old SPoT the other day. Matt is just down the hall from me.

The only cause we can think of for the symptom you describe (SPoT spontaneously turning off) is that the batteries are breaking contact inside the battery compartment. You'll notice that if you remove the batteries with the SPoT in operation, and then put them back in, it comes up "off". So, if the batteries are momentarily coming loose from the contacts, that would cause this.

The fact that you found powder in the battery compartment, tends to confirm this guess. (Battery labels or SPoT plastic getting ground into powder as the batteries jostle around in there.)

Perhaps the paint shaker cannot impart quite as sharp a "thump" to the SPoT as the handlebars of a bike can. (The one we use actually moves in an "orbital" pattern, sort of a 3D ellipse, sort of like a football, but it may be too, um, "smooth" in its motion.)

Since I personally know people who have mounted their SPoT that way who've not had the problem, our fingers are crossed that the battery compartment is just a tiny bit "looser" on your old SPoT than is the average, and that the replacement is "tighter".

If you still have the problem (and only do this IF you still see the problem) you might try jamming a small, thin object, like a folded over business card, between the battery door and the batteries, to tighten things up a bit in there. Also, make sure the screws on the battery door are nice and snug (not so tight as to strip the threads, of course, but snug).

We sincerely hope this one works better!

[ghostbuster2]

A foam ear plug is what I use to keep the batteries from vibrating around in my Garmin 60CSX and SPOT unit. Put it on top of the batteries and instqall the cover. I carry my SPOT in the fenderbag of my dirtbike. It has seen about 2000 miles of offroad use and is still going strong.