Let's Talk PLBs......

Posted by: hikermor

Let's Talk PLBs...... - 10/30/12 03:42 AM

It's time I was dragged, kicking and screaming, into the 21st century. It's about time I started carrying a PLB on my trips, which are frequently solo backpacking or bike touring excursions. I want something that is reasonably lightweight, dependable, and a good value. I welcome any comments you might have.....
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 10/30/12 03:49 AM

ACR ResQLink is the best value and performer of current PLBs. The McMurdo Fast Find / Kanaad Safelink are a not very distant second. Given they cost about the same... I carry the ACR currently.
Posted by: KenK

Re: Let's Talk PLBs...... - 10/31/12 12:14 AM

Its hard to follow up a recommendation by Doug :-) , but if it means anything ... +1 on what Doug said.

I purchased a PLB a while back, have never used it, but it offers a nice level of comfort knowing that my family and I can get help if needed. Its a really REALLY cheap insurance policy that takes advantage of some amazing technology ... if you want to think of it that way.

Still, I continue to plan to carry what I (or we) need to be as "findable" as possible - night or day, and to be prepared to wait out the time until rescue comes (figuring a day or two ... or three uncomfortably).
Posted by: gonewiththewind

Re: Let's Talk PLBs...... - 10/31/12 01:20 AM

I have several ACR ResQLink devices I use for work. I have not had to use them, but they are light and have great capabilities. I also just returned from 3 weeks in northern Arizona teaching land navigation, and used the InReach from Delorme. They were great and maintained a good signal even deep in the canyons. It also allows two way comms, and the account is very flexible in how you manage the costs. There are two versions, I have the one that works with the Delorme Pn-60W GPS. Comms were great and I could track the students real time. It is a consideration. It also has SOS capabilities similar to a PLB, without the strobe light. It can work as a stand alone or with the GPS or a smartphone to communicate. I am very pleased with it.
Posted by: Phaedrus

Re: Let's Talk PLBs...... - 10/31/12 04:02 AM

I don't have one yet but I plan to pick up a PLB soon. Doug's word is pretty much gospel to me when it comes to things like this, so I'll be buying whatever one he recommends!
Posted by: Glock-A-Roo

Re: Let's Talk PLBs...... - 10/31/12 02:12 PM

I've been running the ACR Res-Q-Link since the spring of this year. I got the subscription for the 'I'm OK' notification service, which has worked well.

Good info there from Montanero, as always.
Posted by: Pete

Re: Let's Talk PLBs...... - 11/01/12 12:43 AM

I don't use a PLB ... but I have been happy with my SPOT2 device.
If you get something reliable - it should work out for you.

cheers,
Pete2
Posted by: comms

Re: Let's Talk PLBs...... - 11/03/12 02:18 AM

SPOT2, here. carry it for every road trip and off grid trip.
Posted by: Russ

Re: Let's Talk PLBs...... - 11/03/12 02:22 AM

I carry a ResQLink in my overwater survival vest. My McMurdo Fast Find was moved into the GHB kept in the back of my truck.
Posted by: celler

Re: Let's Talk PLBs...... - 11/07/12 12:28 AM

I like separating my emergency and check-in/non-emergency communications and a small bit of redundancy. McMurdo Fast Find on my belt and Delorme InReach in the pack. I really love the two-way capability of the InReach and don't worry about using up the battery for routine communications. The InReach moves to my pack strap if I want to do tracking.
Posted by: GoatMan

Re: Let's Talk PLBs...... - 12/06/12 06:14 AM

So is the consensus that an InReach as reliable as a standard PLB in an emergency, assuming good batteries?
Posted by: gonewiththewind

Re: Let's Talk PLBs...... - 12/06/12 01:00 PM

I have used the InReach quite a bit for communications, but not as a PLB. That is something you can't just go out and test, without getting into trouble. I would defer to Doug Ritter on how well it has performed in tests. It is great for communicating though.
Posted by: JohnN

Re: Let's Talk PLBs...... - 12/06/12 02:39 PM

Keep in mind the InReach is bulkier than the current generations of PLBs, and has a monthly subscription. To use it effectively, you pair it with another electronic device, so it is more complicated, and heavier overall.

Personally, I use the same approach as Celler. I have a FastFind as the primary device, and then have a InReach as a supplementary device.

If I could only have one device, it would be my GPS enabled FastFind (or similar ACR product).

-john
Posted by: RNewcomb

Re: Let's Talk PLBs...... - 12/06/12 04:10 PM

JohnN - Just curious - is the battery replaceable on your FastFind? Or do you just replace it every six years?
Posted by: CANOEDOGS

Re: Let's Talk PLBs...... - 12/06/12 06:44 PM


any chance of a no frills,one button SOS PLB in the works for under $100?..i would like a PLB that i can take on canoe trips that i can afford,no monthly fees,does not have all those "track me" send a message and so on add on's.just something i can carry on my belt so if my old 67YO body gives out i can flip open a cover and hit a big red button and a GPS gizmo will bring help.
there is no cell phone coverage,in fact it gives out just after you leave Orr Minnesota,which is fine with me.
renting a satellite phone would cost $11 a day,last time i checked with a outfitter so that's around a $150 for my normal two week trips plus if i,m down and in shock with a busted hip or pinned under a tree--that happens!!!--fooling around to get a satellite phone to connect would be the end of me--
so..any back room talk about a one big red button SOS PLB for under $100 and no fees???..
Posted by: JohnN

Re: Let's Talk PLBs...... - 12/06/12 07:38 PM

Originally Posted By: RNewcomb
JohnN - Just curious - is the battery replaceable on your FastFind? Or do you just replace it every six years?


I have a 210. My understanding is you have to send it back to them for battery replacement.

-john
Posted by: JohnN

Re: Let's Talk PLBs...... - 12/06/12 07:43 PM

Originally Posted By: CANOEDOGS

any chance of a no frills,one button SOS PLB in the works for under $100?..i would like a PLB that i can take on canoe trips that i can afford,no monthly fees,does not have all those "track me" send a message and so on add on's.just something i can carry on my belt so if my old 67YO body gives out i can flip open a cover and hit a big red button and a GPS gizmo will bring help.


I don't know about mfg plans and $100 price points, but about $250 can get you that right now:

http://www.landfallnavigation.com/fastfind220.html
http://www.landfallnavigation.com/acr375plb.html

Personally, my guess is $100 is unlikely. In that price range you might be able to get an older, used model and then replace the battery.

-john
Posted by: Phaedrus

Re: Let's Talk PLBs...... - 12/06/12 08:57 PM

The non-user replaceable battery is part of the legal standard.
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/07/12 12:43 AM

Originally Posted By: RNewcomb
JohnN - Just curious - is the battery replaceable on your FastFind? Or do you just replace it every six years?



The current generation PLBs require them to be sent to a service center for battery replacement. Having said that, nobody is ever going to do that. New generations of PLBs are appearing every couple years. With each generation they get smaller, lighter and deliver better performance. Nobody is going to replace the battery after six years.
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/07/12 12:47 AM

Originally Posted By: Phaedrus
The non-user replaceable battery is part of the legal standard.


Sorry, but that is not correct. There are aspects of the standard that make it a bit of a challenge to have a user replaceable battery given how small the latest units are, but it could be done, technically. It would certainly add size and weight, and cost as well. The first generation McMurdo PLB, much larger than the current generation, had a user replaceable battery pack. No real reason, see my prior response, to do that today or going forward. Size and weight are king
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/07/12 12:52 AM

Originally Posted By: GoatMan
So is the consensus that an InReach as reliable as a standard PLB in an emergency, assuming good batteries?



Depends on the circumstances. Overall, the PLB is extremely reliable. The jury is still out on the inReach, just not enough data. Certianly they have numerous saves to their credit and you balance any potentially lesser reliability with the ability to use it to two-way communicate and have to balance that. My recommendation to clients at this juncture is always carry a PLB as back-up, Given the small size and modest cost, not a big problem for most. If you can afford the inReach subscription, you can afford the PLB back-up
Posted by: ponder

Re: Let's Talk PLBs...... - 12/07/12 02:36 AM

Originally Posted By: Doug_Ritter
...The current generation PLBs require them to be sent to a service center for battery replacement. Having said that, nobody is ever going to do that ... Nobody is going to replace the battery after six years.


As long as we are giving opinions - IMHO This statement is false. I send in my PLB's back to the manufacturer and have them replaced every five (5) years. If you actually use the PLB's and your life depends on them, you would be an idiot to not maintain these and ANY SURVIVAL/RESCUE equipment.
Posted by: Russ

Re: Let's Talk PLBs...... - 12/07/12 02:42 AM

Ponder -- I think what Doug is saying is that no one will replace the battery in an older PLB when the newer models are smaller and more reliable. They won't replace the batteries, they'll get a new PLB.

That said, the ACR ResQLink is pretty small and I'd need a fairly compelling reason to replace it with a newer smaller unit rather than simply replace the batteries.
Posted by: Phaedrus

Re: Let's Talk PLBs...... - 12/07/12 05:53 AM

Originally Posted By: Doug_Ritter
Originally Posted By: Phaedrus
The non-user replaceable battery is part of the legal standard.


Sorry, but that is not correct. There are aspects of the standard that make it a bit of a challenge to have a user replaceable battery given how small the latest units are, but it could be done, technically. It would certainly add size and weight, and cost as well. The first generation McMurdo PLB, much larger than the current generation, had a user replaceable battery pack. No real reason, see my prior response, to do that today or going forward. Size and weight are king



Good to know! I guess I misunderstood that; I thought the reason they didn't have replaceable batteries was legal.
Posted by: Glock-A-Roo

Re: Let's Talk PLBs...... - 12/07/12 04:38 PM

Saw this on ACR's site:

"If you use it...we'll replace it, Free of Charge. Simply submit your story, send us back your used beacon so we can have it mounted on our Wall of Fame and we'll send you a brand new beacon of equal or greater value."

Nice!

The ACR site has this user report where a solo hiker used his PLB to call for help after getting snowed in. I noticed something interesting in the associated SAR report that caught my eye:

"The Tulare County Sheriff Search and Rescue Team requested Kern County's assistance in locating the hiker. He had been activating his portable locator beacon every hour since Friday night."

I thought the accepted practice was to turn on the PLB and leave it on, not cycle it. Thoughts?
Posted by: chaosmagnet

Re: Let's Talk PLBs...... - 12/07/12 05:23 PM

Uh, yeah. You leave it on.
Posted by: Denis

Re: Let's Talk PLBs...... - 12/07/12 05:40 PM

Originally Posted By: CANOEDOGS
any chance of a no frills,one button SOS PLB in the works for under $100?

I actually just ran into such a deal ... Radioworld.ca has some McMurdo Fast Find 210's on clearance for $99. However, I didn't see any reference to them shipping outside of Canada so I don't know if non-Canadians could have access to this deal as well.

It looks like they are older stock and have an expiry date of 07/15. But even with only a 3 year's of life left, it seems like a pretty good deal to me.
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/07/12 06:12 PM

Originally Posted By: Denis
Originally Posted By: CANOEDOGS
any chance of a no frills,one button SOS PLB in the works for under $100?

I actually just ran into such a deal ... Radioworld.ca has some McMurdo Fast Find 210's on clearance for $99. However, I didn't see any reference to them shipping outside of Canada so I don't know if non-Canadians could have access to this deal as well.

It looks like they are older stock and have an expiry date of 07/15. But even with only a 3 year's of life left, it seems like a pretty good deal to me.


PLBS are Country Coded, so an American could not register that PLB in the U.S., PLBs are a dated item so anything more than a month or so old, should be discounted. More than a year old, significantly discounted, as we see here.
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/07/12 06:16 PM

Originally Posted By: ponder
Originally Posted By: Doug_Ritter
...The current generation PLBs require them to be sent to a service center for battery replacement. Having said that, nobody is ever going to do that ... Nobody is going to replace the battery after six years.


As long as we are giving opinions - IMHO This statement is false. I send in my PLB's back to the manufacturer and have them replaced every five (5) years. If you actually use the PLB's and your life depends on them, you would be an idiot to not maintain these and ANY SURVIVAL/RESCUE equipment.



Sorry, can't imagine why you would do that. You are going to spend 1/3 to 1/2 the cost of a new PLB, better in most all respects, to keep around an outdated PLB. Like trying to keep an old cell phone working after 4-5 years. That you can do it doesn't mean it makes much sense. But, different strokes.

My recommendation to anyone is upgrade to the latest PLB when your battery reaches it's expiration date.
Posted by: celler

Re: Let's Talk PLBs...... - 12/07/12 09:14 PM

I have to agree with Doug on this one. I gave a couple of PLBs to boaters that needed them with specific directions that they would need to replace the battery soon. Replacing the battery was a do-able expense for someone who had never owned one before and was unaware of the smaller size, expanded capability units. I found out that de-registering a PLB was quite easy. And if you give one away, you definitely want to do that. Similarly, if you loan your PLB out, be sure you have sufficient information from the borrower to attempt to make contact them if it is activated and you receive a call from the authorities.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/10/12 07:11 AM

I carry an ACR SarLink View and a sat phone; its number is entered into the registration record for the PLB. The PLB registration record is updated with activity type and who else is in my party before the journey and removed upon return. The "view" portion of the SarLink View is a LCD screen which displays the GPS coordinates; I don't think the "view" is really needed as sar would have that information upon transmission so I look at it as a nice to have - can't hurt knowing GPS coordinates which could be useful if communicating on the sat phone. I purchased the SarLink View before the ResQLink was on the market.
Posted by: celler

Re: Let's Talk PLBs...... - 12/10/12 01:04 PM

Originally Posted By: QuietStove
<snip> can't hurt knowing GPS coordinates which could be useful if communicating on the sat phone. <snip>


You did not mention which sat phone you were using, so this may not apply to you. Globalstar phones have a "hidden" menu that is only available while a call is in progress. It will provide you reasonably accurate coordinates using their satellite triangulation. Potentially useful if a GPS is not handy.
Posted by: RNewcomb

Re: Let's Talk PLBs...... - 12/10/12 03:21 PM

Originally Posted By: Doug_Ritter
Originally Posted By: RNewcomb
JohnN - Just curious - is the battery replaceable on your FastFind? Or do you just replace it every six years?



The current generation PLBs require them to be sent to a service center for battery replacement. Having said that, nobody is ever going to do that. New generations of PLBs are appearing every couple years. With each generation they get smaller, lighter and deliver better performance. Nobody is going to replace the battery after six years.


Doug - That makes perfect sense!
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/10/12 10:37 PM

[quote="celler"][You did not mention which sat phone you were using/quote]

Iridium 9555 and I do not think it has a feature for GPS coordinates. I used GlobalStar years ago but switched to Iridium when GlobalStar was having service issues. Now that their second generation constellation is active I may have a look at them when i'm ready for my next sat phone. I believe the Iridium 9575 has a GPS tracking feature which looks interesting.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/10/12 10:41 PM

I found an interesting link on ResQLink battery replacement.

http://advrider.com/forums/showthread.php?t=749245


I don't have enough information to know if changing the battery is a straight forward process for the technically inclined or if it is a matter of revenue generation for the PLB company. Or perhaps since it is a life saving device not letting consumers toy with battery replacement is a wise decision.

Posted by: celler

Re: Let's Talk PLBs...... - 12/10/12 11:50 PM

Originally Posted By: QuietStove
<snip>I don't have enough information to know if changing the battery is a straight forward process for the technically inclined or if it is a matter of revenue generation for the PLB company. Or perhaps since it is a life saving device not letting consumers toy with battery replacement is a wise decision.


That looks like a proprietary battery pack custom made for ACR. You can find people that will replicate such things with the shrink wrap and all, but there's going to be some soldering involved. I seriously doubt you will find one ready made and ACR for sure won't sell it to you.

That said, I would do something like this for the rechargeable battery pack for my cordless drill. I would not do it for something involving life critical communications. I want to know the lithium batteries are fresh, I want some QC involved, and I would like it tested before its handed back to me. If it were an Ipod a cell phone with a permanent battery, the market would offer solutions cheaper than the manufacturer. But the life critical nature of this device and the litigation potential will likely leave the manufacturers as the only source.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/11/12 12:20 AM

Agree that ACR will not sell a battery pack for any of their PLBs. The 9V battery appears to be made up of Panasonic Lithium-manganese dioxide cells.
Posted by: Russ

Re: Let's Talk PLBs...... - 12/11/12 12:23 AM

There are also seals to consider when opening up a PLB to change the batteries. At least for me, I want to know that the unit is sealed correctly, can be submerged and still functions 100% with the fresh batteries.

That said, the only time the battery will be used is when I consider my life to be on the line and at that point, the ResQLink is mission complete. ACR might want it for their "Wall of Fame" but I'll put it on mine and buy a new unit.
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/11/12 04:39 PM

Originally Posted By: QuietStove
I found an interesting link on ResQLink battery replacement.

http://advrider.com/forums/showthread.php?t=749245


I don't have enough information to know if changing the battery is a straight forward process for the technically inclined or if it is a matter of revenue generation for the PLB company. Or perhaps since it is a life saving device not letting consumers toy with battery replacement is a wise decision.



Penny wise, Pound STUPID!
Posted by: JohnN

Re: Let's Talk PLBs...... - 12/11/12 06:26 PM

It would be interesting to know if the manufacturers even plan to do the battery replacement of your 6-10 year old unit. That would require them to keep spares (that have a shelf life), and the labor to open, replace, reseal the units. You could imagine it might make sense for them to simply send you a lower end current unit.

-john
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/11/12 07:33 PM

Originally Posted By: JohnN
It would be interesting to know if the manufacturers even plan to do the battery replacement of your 6-10 year old unit. That would require them to keep spares (that have a shelf life), and the labor to open, replace, reseal the units. You could imagine it might make sense for them to simply send you a lower end current unit.

-john


WRT replacement batteries, due to expiration dates, nobody really "stocks" these for any distress beacons. They generally build to order or once they have a period of consistent sales history, will build to anticipated sales based on that. It is a PITA for the manufacturers and PLBs are headed to becoming throw-away items (but, please don't actually throw them away in the trash without disconnecting battery). EPIRBs and ELTs are a different matter being used in mandated carriage and these they can plan on replacement with required inspections that ensure sales of replacement batteries for a period of time. In any case, no way this will ever be cheap done correctly and considering market size, etc.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/12/12 08:07 AM

Originally Posted By: "Doug_Ritter"
Penny wise, Pound STUPID!


Yup. Agree. Battery replacement service is more than just replacing the battery.

http://www.acrartex.com/support/faqs/personal-locator-beacon-faqs/#q-4722
Posted by: spuds

Re: Let's Talk PLBs...... - 12/20/12 10:06 PM

So for a schmuck who knows nothing,is the ResQlink the one to have?

What other models?

Best price per ability on units?

I want it for if truck goes over the hill or stuck in snow storm.

Is snow an issue for these things to work,have to wait for clear weather?

Would this work in a collapsed building or line of sight to sat essential?

Experts,need your advice!

Edit-looks like resqlink is the ideal?
Posted by: hikermor

Re: Let's Talk PLBs...... - 12/21/12 02:28 AM

You will find DR's analysis of the available units most informative. Check the main portion of ETS.

I am probably going to get the ResQLink, primarily because of the compact size and low weight. If you are going to use your PLB in conjunction with a vehicle, that probably need not be an important consideration.
Posted by: gonewiththewind

Re: Let's Talk PLBs...... - 12/21/12 03:52 PM

The Res-Q-Link does not float, so get the pouch that they sell that will make it float in case you are going to be around water. It also is a convenient belt pouch for it. It is small enough that it is easily carried in a pocket though.
Posted by: Russ

Re: Let's Talk PLBs...... - 12/21/12 04:03 PM

My ResQLink is carried in a pouch on my aviation survival/flotation vest. Besides the pouch, it is also tied in with a paracord lanyard. It doesn't float and in the environment I could use it, the water is very deep, so I keep it firmly attached to something that will float -- me.
Posted by: JohnN

Re: Let's Talk PLBs...... - 12/21/12 05:11 PM

Originally Posted By: spuds
So for a schmuck who knows nothing,is the ResQlink the one to have?

What other models?

Best price per ability on units?

I want it for if truck goes over the hill or stuck in snow storm.

Is snow an issue for these things to work,have to wait for clear weather?

Would this work in a collapsed building or line of sight to sat essential?

Experts,need your advice!

Edit-looks like resqlink is the ideal?


You should be able to buy a compact GPS enabled PLB for around $250 these days if you look around.

Examples:

http://www.landfallnavigation.com/fastfind220.html
http://www.landfallnavigation.com/acr375plb.html

-john
Posted by: KenK

Re: Let's Talk PLBs...... - 12/21/12 11:33 PM

Originally Posted By: spuds
I want it for if truck goes over the hill or stuck in snow storm.

Is snow an issue for these things to work,have to wait for clear weather?

Would this work in a collapsed building or line of sight to sat essential?


I'll make an attempt to answer your questions about how the PLB will operate in poor weather and/or poor light-of-sight conditions.

When a 406 MHz PLB is activated it transmits a signal that identifies the PLB (I assume there is a unique ID code).

If you are in a latitude between 70 degrees north & 70 degrees south that signal will be picked up almost immediately by geostationary (GEO) satellites that are positioned at the equator.

If you are not within that 70 degree latitude area - or marginal - that signal can still be picked up by low-Earth orbiting (LEO) satellites. Because LEO satellites have a more narrow view of the Earth it may take some time for one of them to come into "view" of your PLB signal. This potential time delay is longer at the equator and shorter at the poles - up to 1.5 hours. The maximum delay in the United States is about 1 hour.

It is my understanding that transmission of the PLB signal to the GEO and LEO satellites does not require direct line-of-sight, and will do well even in poor weather. The effect of mountains and buildings in blocking the signal will depend on the type and location of the receiving satellite - your mileage may vary there.

Receiving the PLB signal alone is of limited benefit if the system does not know your location.

There are two methods of identifying the location of the PLB signal: GPS and Doppler. The GPS method requires a clear view of the sky, but the Doppler method is more robust and shouldn't be impacted by weather.

GPS:
If your PLB is equipped with a built-in GPS capability, AND you have a reasonably clear view of the sky, AND the GPS has succeeded in locking in on enough GPS satellites to provide position coordinates, then the PLB transmission will include those position coordinates to both the GEO satellites (potentially instantaneous) and the LEO satellites (may be delayed up to 1.5 hours). The accuracy of the GPS position is within about 400 feet.

Historically GPS has required a fairly clear view of the sky, but in the last few years more advanced GPS chipsets can lock onto GPS satellites even without a direct view of the sky (under vegetation, inside buildings, ...). I'm pretty sure all modern PLBs have those more advanced GPS chipsets.

Doppler:
If your PLB is not equipped with a built-in GPS capability, or you do not have a clear view of the sky, your position can still be determined by the LEO satellites using a Doppler effect - though there can be that delay associated with the LEO satellites. The accuracy of the Doppler position is within 1.2 to 3 miles, but averaging about 1.5 miles.

Note that because the GEO satellites are geostationary there is no Doppler effect - they aren't moving relative to your location, so they cannot find your location using this method.

It seems to me that the +/-1.5 miles area is pretty big, but its far far better than no location information at all. At least they will be looking for you nearby.

DO get a PLB that has an onboard GPS capability.

If you activate the PLB, then you'll want to give it as good a view of the sky as you can. If you're in your vehicle, put it outside. If you're in a collapsed building, put it near a window - or an opening if possible. Getting that GPS position means they'll essentially come right to you. Without that GPS position they'll need to search for you which will take more time.

Hopefully that helps,

Ken
Posted by: Doug_Ritter

Re: Let's Talk PLBs...... - 12/22/12 12:38 AM

Originally Posted By: KenK
Originally Posted By: spuds
I want it for if truck goes over the hill or stuck in snow storm.

Is snow an issue for these things to work,have to wait for clear weather?

Would this work in a collapsed building or line of sight to sat essential?


I'll make an attempt to answer your questions about how the PLB will operate in poor weather and/or poor light-of-sight conditions.

When a 406 MHz PLB is activated it transmits a signal that identifies the PLB (I assume there is a unique ID code).

If you are in a latitude between 70 degrees north & 70 degrees south that signal will be picked up almost immediately by geostationary (GEO) satellites that are positioned at the equator.

If you are not within that 70 degree latitude area - or marginal - that signal can still be picked up by low-Earth orbiting (LEO) satellites. Because LEO satellites have a more narrow view of the Earth it may take some time for one of them to come into "view" of your PLB signal. This potential time delay is longer at the equator and shorter at the poles - up to 1.5 hours. The maximum delay in the United States is about 1 hour.

It is my understanding that transmission of the PLB signal to the GEO and LEO satellites does not require direct line-of-sight, and will do well even in poor weather. The effect of mountains and buildings in blocking the signal will depend on the type and location of the receiving satellite - your mileage may vary there.

Receiving the PLB signal alone is of limited benefit if the system does not know your location.

There are two methods of identifying the location of the PLB signal: GPS and Doppler. The GPS method requires a clear view of the sky, but the Doppler method is more robust and shouldn't be impacted by weather.

GPS:
If your PLB is equipped with a built-in GPS capability, AND you have a reasonably clear view of the sky, AND the GPS has succeeded in locking in on enough GPS satellites to provide position coordinates, then the PLB transmission will include those position coordinates to both the GEO satellites (potentially instantaneous) and the LEO satellites (may be delayed up to 1.5 hours). The accuracy of the GPS position is within about 400 feet.

Historically GPS has required a fairly clear view of the sky, but in the last few years more advanced GPS chipsets can lock onto GPS satellites even without a direct view of the sky (under vegetation, inside buildings, ...). I'm pretty sure all modern PLBs have those more advanced GPS chipsets.

Doppler:
If your PLB is not equipped with a built-in GPS capability, or you do not have a clear view of the sky, your position can still be determined by the LEO satellites using a Doppler effect - though there can be that delay associated with the LEO satellites. The accuracy of the Doppler position is within 1.2 to 3 miles, but averaging about 1.5 miles.

Note that because the GEO satellites are geostationary there is no Doppler effect - they aren't moving relative to your location, so they cannot find your location using this method.

It seems to me that the +/-1.5 miles area is pretty big, but its far far better than no location information at all. At least they will be looking for you nearby.

DO get a PLB that has an onboard GPS capability.

If you activate the PLB, then you'll want to give it as good a view of the sky as you can. If you're in your vehicle, put it outside. If you're in a collapsed building, put it near a window - or an opening if possible. Getting that GPS position means they'll essentially come right to you. Without that GPS position they'll need to search for you which will take more time.

Hopefully that helps,

Ken


Ken,

You are hereby appointed assistant PLB expert here. :-)

One thing I can add. PLBs are equipped with homing signal on 121.5 MHz. So, when the beacon is located within a couple miles via Doppler, that is quite adequate to be in range of the homing signal and SAR can accurately home into your location from the air or the ground. That's what the homing signal is for.

Beyond that, more and more SAR aircraft (USCG, CAP and Air Force) are now equipped with digital 406 MHz direction finders that can home in on the intermittent, but much stronger (5W), 406 MHz signal. Homing from as far as 120 miles has been seen in real world SAR cases.

Doppler and this dual homing capability is a major advantage that 406 MHz PLBs (and EPIRBs and ELTs) have over alternative distress signaling devices that must have a GPS location to be useful for locating them.
Posted by: Glock-A-Roo

Re: Let's Talk PLBs...... - 12/22/12 12:47 AM

Originally Posted By: Russ
it is also tied in with a paracord lanyard. It doesn't float and in the environment I could use it, the water is very deep, so I keep it firmly attached to something that will float -- me.


I was going to post the same thing. I don't mind that my ResQLink doesn't float because it is always attached with a dummy cord.
Posted by: gonewiththewind

Re: Let's Talk PLBs...... - 12/22/12 04:30 PM

Do you float? lol
Posted by: Glock-A-Roo

Re: Let's Talk PLBs...... - 12/22/12 10:31 PM

Originally Posted By: Montanero
Do you float? lol


Well, if I wind up sinking for good, I don't much care what the fate of the PLB is...
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/05/16 02:05 AM

Thoughts ?

https://www.youtube.com/watch?v=BYgBEPi0jFU
Posted by: hikermor

Re: Let's Talk PLBs...... - 12/05/16 04:21 AM

Originally Posted By: Doug_Ritter
Originally Posted By: QuietStove
I found an interesting link on ResQLink battery replacement.

http://advrider.com/forums/showthread.php?t=749245


I don't have enough information to know if changing the battery is a straight forward process for the technically inclined or if it is a matter of revenue generation for the PLB company. Or perhaps since it is a life saving device not letting consumers toy with battery replacement is a wise decision.



Penny wise, Pound STUPID!


Here is an opinion from earlier in this very thread. Amateur battery replacement doesn't seem like a very good idea for critical equipment.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/05/16 03:05 PM

The expiration date in my SarLink View is 04/2016.

Yes, I decided to open it. I'm certainly am not willing to pay an outrageous $130.00 to send to it someone whom I do not know other than they are "certified" (whatever that means) to "service" my make and model PLB.

The battery in my SarLink is simply two sets of two Panasonic CR14375 (These exact battery cells are available on Amazon.) connected in series and spot-welded with nickle strips at each terminal, then taped together. (Interestingly enough the batteries are dated 02-2020) The wires are then soldered to the tabs, and then entire package is then covered in heat shrink tubing. If one really wants to do a sweet build then by utilizing new Molex connectors 51065-0200 and 50212-8100 one could build a battery pack without having to transfer the current connectors. The "gasket" appears to be silicone and it is not becoming deficient anytime soon.

What I find rather ironic is that the batteries are not soldered to the circuit board. On most electric shavers and toothbrushes the batteries are spot-welded and soldered in place which makes an excellent connection but that is not the case on my life-saving PLB. For my PLB it seems the build engineers decided a friction based connection will suffice. Connectors are simply not as reliable as a soldered joint. And this connection IMHO is more of a deficiency on this make and model PLB than any battery build (certified or amateur).





Posted by: hikermor

Re: Let's Talk PLBs...... - 12/05/16 06:18 PM

It would appear that you know your way around electronics. If so, carry on and enjoy the savings!

I think this whole thread lays bare one of the problems inherent with electronic gadgets. You are dependent upon their reliability and the reliability of the system of which they are part. Experience, at least that which gets reported, indicates that PLBs, etc. and their systems work well enough.

Your first, and often best, strategy is to insure that your enterprise is well equipped with materials, knowledge, and skills, to deal with emergencies and glitches.

I note that I started this thread in 2012 seeking information on PLBs. I still have not taken the plunge and purchased -mostly inertia, but also that traditional methods have worked and still do. I make sure that dependable folks (mostly my wife) know my plans and where I will be.
Posted by: bws48

Re: Let's Talk PLBs...... - 12/05/16 06:22 PM

Can you do it yourself? Yes (probably). Should you do it yourself? Maybe, if you have the skills and know what you are doing.

The problem from the manufacture's perspective is probably liability if the user screws up the battery replacement in a critical unit like the PLB, and someone dies as a result of a failed battery replacement. They then get sued over a faulty design that allowed the user to screw up battery replacement.

In a device like a PLB, as an attorney, I would advise the Company to NOT design to allow users to easily change batteries, say like in a flashlight, and to make sure that a certified service is available to change the batteries. IMO, the legal risk of not doing so would be too high.
Posted by: TeacherRO

Re: Let's Talk PLBs...... - 12/05/16 07:43 PM

I note that some satellite phones have an "sos" - would this be similar to a plb?

tro
Posted by: Russ

Re: Let's Talk PLBs...... - 12/05/16 11:43 PM

In my opinion, a PLB (Personal Locator Beacon) is a device that does one thing very well; it sends a signal to a satellite constellation that tells an established SAR system where you are. Your PLB being active at all is your 9-1-1. Because it cannot do anything else, its battery should always be at or near full charge.

Simply because of normal usage, a satellite phone's battery may be at a low state just when you need it most.

my $.02
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/06/16 01:10 AM

Originally Posted By: bws48
Can you do it yourself? Yes (probably). Should you do it yourself? Maybe, if you have the skills and know what you are doing.

The problem from the manufacture's perspective is probably liability if the user screws up the battery replacement in a critical unit like the PLB, and someone dies as a result of a failed battery replacement. They then get sued over a faulty design that allowed the user to screw up battery replacement.

In a device like a PLB, as an attorney, I would advise the Company to NOT design to allow users to easily change batteries, say like in a flashlight, and to make sure that a certified service is available to change the batteries. IMO, the legal risk of not doing so would be too high.

Hi,
What about smoke alarms?
They've had replaceable batteries for decades ...
the liability argument is a non-starter,
if that was the real issue the lawyers would craft a license agreement disclaiming liability, like they already do for every product under the sun

Only recently are 10 year non-replacable batteries smoke-alarms becoming the standard,
and not because something could break in the life saving device,
its because too many people are lazy to replace batteries ,
esp property managers,
so they end up with nonworking fire/smoke alarms.
That and the smoke alarm companies don't sell batteries smile

Like Doug Ritter said, the market is too small,
there is no profit in replaceable batteries

but the whole technology
gets smaller and more reliable
argument doesn't hold anymore
as its been plenty small and reliable for a while now
a 5 year old cellphone is perfect example of this

so it makes sense for individuals like hikers
who wouldn't buy a new one,
to get an old one at low price and replace batteries
provided its compliant with the current standard


and yes , it doesn't make sense to ship old one in for service/battery replacement,
esp if you're a boater/flyer/offroader/business ,
for those people it makes sense to buy a new one,
esp from liability perspective (your lawyers are weak :D)
Posted by: Quietly_Learning

Re: Let's Talk PLBs...... - 12/06/16 02:42 AM

My question in buying one used and replacing the batteries is, how do I know it was stored properly and will work when my life depends on it?

I have bought a lot of slightly used gear but I stay away from used electronics for the back country.

If there is a way to be sure it will work I'm listening...
Posted by: chaosmagnet

Re: Let's Talk PLBs...... - 12/06/16 04:31 AM

The engineering problem for smoke alarm batteries is very different than the one for a PLB. A PLB requires much more power and is subject to wildly different environmental factors in terms of temperature, pressure, water, dust, shock, and movement. A smoke alarm has a test mode that does not activate a worldwide rescue system. A PLB would probably have to be a lot bigger to hold enough AA batteries to reliably have enough power compared to the batteries they use today.

I am not saying it could not be done, especially with CR123A lithium primaries and a different form factor, but it is not the same engineering problem as a smoke detector.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/06/16 05:22 AM

Originally Posted By: bws48
In a device like a PLB, as an attorney, I would advise the Company to NOT design to allow users to easily change batteries, say like in a flashlight, and to make sure that a certified service is available to change the batteries. IMO, the legal risk of not doing so would be too high.


I'm pretty sure AEDs have user replaceable batteries.
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/06/16 09:15 AM

Originally Posted By: Quietly_Learning
My question in buying one used and replacing the batteries is, how do I know it was stored properly and will work when my life depends on it?

I have bought a lot of slightly used gear but I stay away from used electronics for the back country.

If there is a way to be sure it will work I'm listening...

Hi,
There is talk of a self-test feature,
a switch/button on the device

some devices offer a paid subscription service with free 2 day triel, to get a email/sms when performing a test , see 406link.com
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/06/16 09:33 AM

Originally Posted By: chaosmagnet
The engineering problem for smoke alarm batteries is very different than the one for a PLB. A PLB requires much more power and is subject to wildly different environmental factors in terms of temperature, pressure, water, dust, shock, and movement. A smoke alarm has a test mode that does not activate a worldwide rescue system. A PLB would probably have to be a lot bigger to hold enough AA batteries to reliably have enough power compared to the batteries they use today.

I am not saying it could not be done, especially with CR123A lithium primaries and a different form factor, but it is not the same engineering problem as a smoke detector.

Hi,
What are you talking about? A 10 year plb?

I used smokealarm as an example of a lifesaving device with replacable batteries,
since PLBs already have those,
and yes they are CR123A LiMnO2 (Lithium Manganese Dioxide)
The website to go along with video above is
new-batteries-for-a-sarlink-plb

Posted by: chaosmagnet

Re: Let's Talk PLBs...... - 12/06/16 03:03 PM

All I meant is that the engineering problem for user replaceable batteries is very different for a PLB than for a smoke detector.

Personally, I think a flashlight-like form-factor of a tube with the batteries in series would work well for a PLB, but I've got too much to do to learn enough to design a competing PLB.
Posted by: Quietly_Learning

Re: Let's Talk PLBs...... - 12/06/16 03:15 PM

Originally Posted By: EMPnotImplyNuclear
Originally Posted By: Quietly_Learning
My question in buying one used and replacing the batteries is, how do I know it was stored properly and will work when my life depends on it?

I have bought a lot of slightly used gear but I stay away from used electronics for the back country.

If there is a way to be sure it will work I'm listening...

Hi,
There is talk of a self-test feature,
a switch/button on the device

some devices offer a paid subscription service with free 2 day triel, to get a email/sms when performing a test , see 406link.com


Glad I asked. Thank you for the info and link!

The website is good to check out for anyone owning or thinking of owning an ACR or ARTEX PLB.
Posted by: bws48

Re: Let's Talk PLBs...... - 12/06/16 06:01 PM

Originally Posted By: EMPnotImplyNuclear

What about smoke alarms?
They've had replaceable batteries for decades ...



I'm thinking of the jury's reaction. Smoke alarms are, as you say decades old, and people are very familiar with them. I see it being argued that PLB's are "new" "exotic" "complex" etc. and therefore require "expert" maintenance, including, for example, battery replacement.

Analogy's to other equipment, smoke detectors, AED's and probably other examples would be argued, but are not definitive and guaranteed proof and protection. Neither are licencing agreements, no matter how strongly worded.

Even if the manufacturer wins, it is expensive and they still get bad publicity of allegedly designing faulty/defective equipment that "killed people." And if they lose, it gets really expensive.

Better to avoid the risks with "non-user replaceable" batteries. That would be my recommendation, anyway.
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/07/16 09:30 AM

Originally Posted By: bws48
...
Better to avoid the risks with "non-user replaceable" batteries. That would be my recommendation, anyway.


Too late smile look at the picture, that's already a regular user replaceable battery right there smile

In fact , it looks very close to hotel door lock battery packs "Saflok 54240 6V Lithium" which are commonly priced under $10, even as low as $4

The connector might be different though, not a "Molex Micro-Latch (51065-0200 housing + 50212-8100 connectors)"
Some other PLBs use 9volt packs
...
I'd bet wherever you live there is a small shop (or a person) that would take such a small job for well under $150
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/07/16 09:38 PM

I have a conversation today with ACR. I understand their position on why they want to service their products. In addition to changing the batteries the unit is then tested for water entry and checked to ensure it complies with the Cospas-Sarsat certification the unit was issued when submit for certification. Plus another way to look at the cost of a $130 (or so) battery replacement is that the unit is good to go for another five years which comes out to $26.00. Also if the PLB is activated for an emergency ACR will replace the batteries for free or provide a brand new unit.

I would like to state that I do not recommend anyone to do their own battery build to service a PLB.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/07/16 09:42 PM

Originally Posted By: EMPnotImplyNuclear

Too late smile look at the picture, that's already a regular user replaceable battery right there smile


It is not a regular replaceable battery. The cells might be commonly available but because the cells are assembled into a pack it is not user replacement. This battery pack cannot be purchased from ACR; therefore it is not user replaceable.
Posted by: AKSAR

Re: Let's Talk PLBs...... - 12/07/16 11:09 PM

Originally Posted By: ChicagoCraig
I understand their position on why they want to service their products. In addition to changing the batteries the unit is then tested for water entry and checked to ensure it complies with the Cospas-Sarsat certification the unit was issued when submit for certification.

I think that is the crux of it. A PLB is actually a fairly complex little item, and there is a lot more too it than just replacing batteries. My RescQLink+ has a GPS chip, a 406 MHz transmitter, a 121.5 MHz transmitter, associated antenna(s), and some sort of processor linking GPS and 406 radio. As just one example of what could go wrong, transmitters are subject of frequency wandering which will degrade performance (I had that happen with an older avalanche beacon). Presumably ACR has all the appropriate test jigs to insure that all those components and features are still in spec. Also, as noted, the waterproofing.

Originally Posted By: ChicagoCraig
I would like to state that I do not recommend anyone to do their own battery build to service a PLB.

I agree. For me the cost of sending back for authorized service is well worth the peace of mind knowing that it will work when I need it most.
Posted by: hikermor

Re: Let's Talk PLBs...... - 12/08/16 12:20 AM

I'll bet that if you use your PLB just once that $130 service fee will seem like a terrific bargain. I felt that climbing rope prices were awfully high until I was hanging by the rope after a leader fall, very much alive and uninjured....That's the way it is with critical gear, whether it is a PLB, rope, good boots, etc.
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/08/16 04:15 AM

Originally Posted By: AKSAR

I think that is the crux of it. A PLB is actually a fairly complex little item, and there is a lot more too it than just replacing batteries.


The crux of it is manual labor (not to mention liability if it doesn't work as expected).

Batteries packs are assembled as needed with fresh cells, new gasket, o-ring (for the antenna shaft), it is connected to a computer and status reads performed against various sensors, and then a RF transmission check, and the unit is water tested to a depth of 30 feet. At least this is what I gather from my conversation with ACR.
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/10/16 09:50 AM

Originally Posted By: ChicagoCraig
Originally Posted By: EMPnotImplyNuclear

Too late smile look at the picture, that's already a regular user replaceable battery right there smile


It is not a regular replaceable battery. The cells might be commonly available but because the cells are assembled into a pack it is not user replacement. This battery pack cannot be purchased from ACR; therefore it is not user replaceable.

Hi,
thats funny,
the nature of a thing (user replacable)
doesn't change if you haven't found where to buy it
see
$7.87
Saflok- 54240 6V-Lithium-1300mAh-Door-Lock-Battery

the user has to do no soldering
If the connector is the wrong kind of connector,
just twist some wires together
but yeah, its highly advanced complex life saving device
that instantly breaks the second the original battery expires
:P
Posted by: AKSAR

Re: Let's Talk PLBs...... - 12/10/16 09:19 PM

Originally Posted By: EMPnotImplyNuclear
but yeah, its highly advanced complex life saving device
that instantly breaks the second the original battery expires
:P
Sorry, but this is a redacted straw man argument. No one here has suggested that a PLB "instantly breaks the second the original battery expires".

What has been suggested is that ANY electronic device is subject to failure over time. The rate of failure may be extremely low but is still finite. If my car sound system fails, it is at worst an annoyance, and will cost some money to fix. If I break my leg in a remote area and my PLB fails it could cost me my life. No amount of money can fix me being dead.

PLBs are subject to rough use in demanding conditions. They are routinely attached to life jackets and gumby suits. They are carried in very wet conditions, hot dry deserts, and extremely cold conditions. A complete and thorough systems check every 5 years (not just a battery replacement) doesn't seem like a bad idea to me for a device that my life might depend on.

It is your life and your money, and you are free to make your own choices. But you have no excuse to belittle those of us who choose to follow the manufacturers recommendations.
Posted by: hikermor

Re: Let's Talk PLBs...... - 12/10/16 10:04 PM

A PLB only has to work once to generate a truly awesome ROI. This doesn't mean that everyone must carry one on every picnic; that's a personal choice and one is at perfect liberty to factor cost into the decision.

Just remember - if you punch the button, you have vastly simplified the task for the responding SAR outfit. That is most likely a good thing.
Posted by: Russ

Re: Let's Talk PLBs...... - 12/10/16 10:33 PM

I view ACR's check-up and battery replacement as an insurance renewal. Their PLB insurance plan comes with a premium just like all insurance plans.
Posted by: TeacherRO

Re: Let's Talk PLBs...... - 12/13/16 06:38 PM

going with the ARC device - its well though of and has a rebate through the end of the year. Question -- it is ok to share this with family? Can my kids take it on a trip ( and use if necessary) without me?
Posted by: AKSAR

Re: Let's Talk PLBs...... - 12/13/16 11:23 PM

Originally Posted By: TeacherRO
going with the ARC device - its well though of and has a rebate through the end of the year. Question -- it is ok to share this with family? Can my kids take it on a trip ( and use if necessary) without me?

Yes, you can loan it to anyone. If the device is activated, the RCC will no doubt call you (or whatever phone numbers you put down when you registered the device). This is good, of course, since you may be able to provide additional info helpful to the SAR team, such as how many people were on the trip, their gear etc.

As a side note, awhile back I had the opportunity to chat with one of the watch supervisors from the Alaska Rescue Coordination Center (RCC) at Joint Base Elmendorf-Richardson (where PLB alerts for onshore Alaska are handled). He said that ELTs (from aircraft) and EPIRBs (boats) tend to have a higher rate of accidental false alerts than PLBs. For example a hard landing is sometimes enough to trigger an aircraft ELT. Likewise EPIRBS which are designed to deploy and activate automatically when a boat sinks sometimes do so by accident. So in some cases (where there is reason to suspect it may be a false alert) they will try to make a few quick calls to verify before requesting a full on rescue mission.

On the other hand, PLBs require several deliberate conscious actions to activate. On mine one has to release and deploy the antenna, which allows access to the button, which then must be pushed to activate. Because of this, PLBs tend to have a lower rate of accidental false alerts. For this reason, the RCC is more likely to immediately request a rescue team to launch.
Posted by: Blast

Re: Let's Talk PLBs...... - 12/14/16 03:31 AM

Just taking a look around to see if I'm needed. I'm not, correct? &#128544;
-Blast
Posted by: ChicagoCraig

Re: Let's Talk PLBs...... - 12/25/16 09:08 PM

Originally Posted By: EMPnotImplyNuclear

Hi,
thats funny,
the nature of a thing (user replacable)
doesn't change if you haven't found where to buy it
see
$7.87
Saflok- 54240 6V-Lithium-1300mAh-Door-Lock-Battery

the user has to do no soldering
If the connector is the wrong kind of connector,
just twist some wires together
but yeah, its highly advanced complex life saving device
that instantly breaks the second the original battery expires
:P


The battery in the above link is not the correct capacity.

Its technical specification are unknown if it is the same or even near cells that ACR utilized.

Its expiration date is not known.

Just twisting the wires together will almost insure that the unit will not function when needed as copper corrodes.
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/26/16 01:07 AM

Originally Posted By: ChicagoCraig
The battery in the above link is not the correct capacity.

Its technical specification are unknown if it is the same or even near cells that ACR utilized.
Its expiration date is not known.

Hi,
Yes, but you know how it says "special order item, ships in 3-5 days"?
That means they build it before they ship it, the expiration date on cells is usually 5-10 years ... and no reason a higher capacity couldn't be arranged


But even at less capacity,
same argument applies
diy plb is better than no plb at all smile

Originally Posted By: ChicagoCraig
Just twisting the wires together will almost insure that the unit will not function when needed as copper corrodes.

smile Where did you hear that?
Unless you dip it in vinegar ...
Taped and sealed in a box, its not going to tarnish for decades
but they do sell grease for sealing connections
Posted by: EMPnotImplyNuclear

Re: Let's Talk PLBs...... - 12/26/16 01:15 AM

More infos, that video guy linked
U.S. Coast guard maintenance procedure card RESCUE AND ASSISTANCE RSS583042.0 REV’D: 08/22/12
RSS583042.0_PLBAUG2012.pdf
another copy MPC_PEPIRB.pdf

It shows how to reinstall battery packs and perform the self-test smile

Other guys that did these things
DIY ACR EPIRB Battery replacement
749245ACR ResQLink PLB Dissassembly- AKA the $10 battery replacement. | Adventure Rider
Posted by: TeacherRO

Re: Let's Talk PLBs...... - 02/15/17 08:57 PM

I'm finding that many companies run coupons, offers, discounts and rebates either on the units or the service... Do a quick search before you buy one