Question about emergency beacons

A kid at my son's school brought some sort of an emergency beacon to school the other day. It was a very high pitched alarm, and it seemed like it was built into his winter coat. I couldn't really see it though, so it could have been a handheld personal alarm. It certainly got our attention, at least initially. After a few minutes it became just another misused suburban alarm - annoying. Probably another piece of paranoid parenting paraphenalia gone wrong.

It did get me thinking though. Is that how those built-in avalanch beacons work? He could activate it at will and it was super loud. Although easily abused, it could be a benefit in a lost/injured in the wilderness scenario. I have to admit though, I'd probably be more responsive to a whistle, unless it was being sounded in threes, in a known S&R situation, or if we were in a low traffic area like the backcountry.

The beacons with which I am familiar work on a radio frequency and are on a lanyard around your neck. When you begin your trip, they are turned on and they continually transmit. After the avalanche, the survivors and/or rescuers turn theirs to receive and systematically comb the area to determine where to dig to recover your body, the usual result.

I used one once, wearing it night and day for three weeks. I never had to use it, thankfully.

Thanks hikermor! Think I'm going to start researching PLBs. I don't have one, but I'm increasingly thinking it might be good insurance. Of course, if i just activated by black berry again I'd mostly have my bases covered. I'm a recovering BB addict.

I think i'm read 3 things here:
- "personall alarms", loud and annoying alarm thingy. to 'scare' people off.
- Avalanch beacons, which transmits radio frequency, which other beacons can read in their 'find' mode. Depending on the model it will show how far and which direction another beacon is. Used by skieers/mountainers to be able to be found and to rescue others. No rescue will be alerted by these beacons, just make you easier to be found.
- Personal Locator Beacons, which uses satelites to alert emergency services.

I think the audible alarm aspect of this beacon makes it not a good fit as an avalanche beacon - snow is an excellent deadener (is that a word?) for sound. Bury your beacon under 4 feet of snow, and see how loud it is then. Plus there are the issues of activation - the advantage of radio waves is they travel through snow to receivers, and they can always be activated.

Also I'm skeptical of audible alarms for use when lost or separated. It may make sense when you are nearby, but depending on terrain and decibels the alarm may not go out as far as you think, and depending on power source, it may not operate for very long - plus it will be very annoying to the person trying to get rescued. A whistle seems to be a better compromise there. You can get tired and stop whistling, but start again when you get your breath back. Once the batteries are out on an audible alarm, its finished sounding for you.

This sounds more like a personal alarm, kind of a "Stranger Danger" type alarm for kids, that they can set off if approached by someone they don't know etc. ymmv

LOL! I hear ya Izzy! aint paranoid parenting great!

I think PLB's are absolutely important pieces of gear. And while some think otherwise I decided to get a SPOT2 GPS messenger and here is my reasoning. YMMV.

Living in the desert there are a lot of areas in my primary endurance training were there is zero cell phone service. Even a basic breakdown on a state route would necessitate a very long walk out, let alone getting anything on trail. So the Help & OK functions are nice back ups for me.

As we all know, we can get behind schedule on the trail. And on great days where I maybe just dawdled too long instead of hitting my turnaround time, I keep going knowing I will be late. DW can either get a text update from me when I'm heading back (preset) or go to the SPOT shared page for a real time update of my position.

Heck even when I am with a group and we just decide to kick back and watch the sunset after a run or swim out there, its good positive reinforcement for my DW to know I am okay b/c I haven't called in when I said I would.

I'm starting to think along the same lines, comms. The Spot2 seems to have everything I need, and shouldn't rekindle my bb addiction. I just happen to be having a decade birthday this week. I think I'll buy one for myself and wrap it up from the family.

I'm starting to think along the same lines, comms. The Spot2 seems to have everything I need, and shouldn't rekindle my bb addiction. I just happen to be having a decade birthday this week. I think I'll buy one for myself and wrap it up from the family.

Congratulations on turning 30!

BLESS YOU!

I advise you to watch out for silver-tongued devils like this one.

HB!

Congrats!

It appears to me that signing up at the 406 link could level the playing field some when choosing between a Spot2 or a PLB. According to what I read on the website you can pay for a yearly service plan that allows you to send "I'm okay" or another pre-set message to up to 5 contacts using the self-test button.

Website is here: http://www.406link.com/index.html

I also wonder if you could pre-arrange with your loved ones that if you send, say three "I'm okay" messages within a minute or two then that means "come help me" or something to that effect. If I'm right, that would mean it could function basically like the Spot2 except also have the increased reliability of a PLB.

I haven't looked at how the costs might compare.

LOL! You guys are making this birthday much easier to take.

Thanks Ann! Back to researching I go!

Congratulations with 30



Hmm.... Will a sequence of identical messages in short intervals be interpreted as one (repeated) attempt of sending the same message?

I very much like the idea - and it would be GREAT to have some "I'm fed up/in non-immediate distress and wanna go home" - message to friends and family. But before such a code can be used, someone should actually test how frequent you reliably can push the "I'm here" button on that particular system. Oh, and the "code" (number of times to press that button) should take into account some expected failure rate of that kind of message. What if your spouse receives 2 such "I'm OK" messages? Is that you pushing the wrong button? Or is it 3 messages where one is lost?

This is an interesting notion. To avoid ambiguity, I would follow the "no news is good news concept." The only message that would then be sent to family would be a low level emergency sort of thing - Please meet me at the trailhead, etc.

My wife is of the, "no news, no calls w/in plan window, means he is dying in the desert". (very slight exaggeration).

Before going with SPOT I was heavily swayed by ACR. In fact I still carry a very old, but reliable rubber button ACR Firefly strobe that ran on those lipstick style mercury or lithium cells before I converted it to CR123.

Anyway, I have never seen a dedicated PLB act as a I'm Okay function using the test sequence. Interesting but honestly I think its trying to make something into something it is not. I mean, we do that all the time but somehow to me it feels weird using a test function as a communication function.

SPOT2 messages are sent over several minutes. You could not hit the button multiple times for multiple updates going to the recipient.

What SPOT2 does very well (w/ some learning) is track the unit online. For hiking I usually set up a Shared Page for my wife to see online. When in Track mode the unit pings the website every ten minutes and to make sure there are no gaps, it sends the last one (maybe two) pings to make sure the gap is filled in. This way DW can see where I am at. For some of my routes she knows my exact turnaround (hilltop, river, etc) so she can see right away if I am heading in, heading out, and so on.

In the interests of accuracy and full disclosure,, I must state that whatever silver might have been resident in my tongue has long since migrated to my hair....

Comms, how would one go about making that conversion? I have some of the same units - still functional with the original fifteen year old batteries, but I would like to keep them working...

Here is an Ebay source for both the strobe and conversion cap, you could contact the seller to see if they will sell just the cap:

NEW SDU-5/E Distress Strobe w/conversion cap for cr123

Pete

Thank you very much!

A conversion cap for using a pair of CR123 batteries
to power a SDU-5/E Distress Marker Strobe light can be found here

http://www.prc68.com/P/Prod.html#B

I have no experience with these - just Googled for it because the
question came up above.

They work great.

Any comments on how the PRC-90 Battery Adapter works?

No, but in my experience they have a good reputation, so I don't see why it wouldn't work. Military uses a lot of their stuff adapters for training and such, since they can use cheaper batteries for training.

Thanks Doug. I ordered the 90BAv3. I have an old PRC-90 and while it came with a functional battery on receive, I have no way of knowing how long it would last if I needed to transmit.

PRC90 is a pretty good basic emergency radio.

It transmits both voice and morse on 243.0 MHz (Int'l air distress & guard on every military UHF radio I've used) and also voice on 282.8 MHz (Joint/combined on-the-scene voice) aka SAR common. That combined with a PLB should provide pretty good comms; bring the outside world into range and then talk to it.

Just another hope-I-never-need-to-use-this piece of gear.

quite some time ago I purchased a brass cap fitting to convert my ACR Firefly (SDU5/e) from a mercury battery to CR123 this site. Works great.

Thanks for the info comms!! Very helpful to know. There's lots to consider but I agree, I don't want to use it in a way it's not intended for because it leaves more margin for error. I'm still on the fence about 1-way vs 2-way communication. Seems a combo of PLB and cell phone might be the best way to go.

LOL!!!

Of course there are pros and cons to each method chosen, and everyone should use what they are most comfortable with after reviewing the facts, but that being said I think I may have done a poor job presenting the information. Allow me to attempt again.

As I understand it there are different ways of self-testing a PLB. The most basic way is you push the self-test button, the PLB lights up, and you're confident that it still works. A more advanced kind is a through-satelite self test, where a signal is actually transmitted. According to the website:



So the signal goes from PLB to satelite to Safelife receiving station, which, if you have signed up for the service, with then send you an email informing you that the signal was received. This is all part of ACR's PLB "self test" function.

If your PLB is already sending a benign signal, and you're getting an email or text message informing you when the signal is received, why not extend that service just a little farther to have it sent to the email(s) of your choice, with the pre-programmed message of your choice?

I guess what I'm saying is that through-satelite self-testing, as opposed to a basic self-test, is already a communication function--you're simply communicating with empty air. 406 link is merely a way to connect that communication to a recipient.

But hey, I'm not an expert or anything. No affiliation.

thanks ann. that sounds like a good idea!

the more i learn, i realize how little i know. i just wish i had the money to test it all out!

Recent update from NOAA:
http://www.noaanews.noaa.gov/stories2011/20110120_sarsat.html

An apparent PLB save:
http://satellite.tmcnet.com/news/2011/04/24/5464317.htm

Another vote in favour if carrying one, especially innremote locations.

Actually, given the "Texas" mention, I suspect it was a SPOT save, not a PLB. Regardless, a win for satellite distress alerting

That would be SPOT correct? I believe their response center is located in Texas. Whatever company made or manages the PLB, good job.

I'm not sure what type of beacon was attached to the kid at your school. The SPOT devices don't have a loud audible alarm.

I can see an argument both ways. If you are truly remote, you need a satellite-based locater with GPS. But it doesn't hurt to also have a device that makes really loud sounds ... like one of those 130-dB horns. Some people carry them to fotball games, and stuff like that. It would helpful for guiding a rescue team when they get close.

cheers,
Pete #2

Or simply use the whistle that should be somewhere on you. Whistles work extremely well, often at surprising distances and are quite distinctive. I tend to associate the loud air horn with drunken football fans.

That nice fire you have built also aids rescuers. It is both visible, both flame and smoke, and can be smelled at a distance as well. Just don't build a fire in dry conditions..