Epirb Digital or Analogue

[Crackerjack]

Does anyone know the difference between analogue and digital epirbs.

we just want to go and play outside and not sure what one we have to buy

[Marlin_Mike]

Either or mate.


Mike

[Hamish73]

All you need to know is here
http://www.gme.net.au/marine/PDFs/EPIRB_fact_sheet.pdf

Analogue are getting very cheap as they are effectively useless as of 2009
I was in a boating chain store today and overheard the manager saying that they will be reducing the price of the analogue unit to $50.

[Black_Rat]

I picked up a GME MT400 406 MHz for $399 yesterday. Sent in an online form to register it last night with my name with details and contacts in the event it is activated and a description of my boat.
I had a reply by 10am this morning saying it has now been registed with the Australian Maritime Safety Authority.

I don't think this is possible with the analouge :-/ $400 is cheap insurance really :) Considering boat inurance is for me around $400-00 a year and the EPIRP has a battery warantee lifespan of 6 years or $66.66c a year ;D The official battery replacement date is March 2014 which is about $23.52 a year ;D

[Spaniard_King]

Dont matter what you buy as long as it's the new frequency model as the old one wont be monitored after 2009

Garry

[FNQCairns]

I picked up a GME MT400 406 MHz for $399 yesterday. Sent in an online form to register it last night with my name with details and contacts in the event it is activated and a description of my boat.
I had a reply by 10am this morning saying it has now been registed with the Australian Maritime Safety Authority.

I don't think this is possible with the analouge :-/ $400 is cheap insurance really :) Considering boat inurance is for me around $400-00 a year and the EPIRP has a battery warantee lifespan of 6 years or $66.66c a year ;D The official battery replacement date is March 2014 which is about $23.52 a year ;D

So what is the deal to keep one of these legal after the 6 years are up? or does it stay legal till 2014?

cheers fnq

[Black_Rat]

So what is the deal to keep one of these legal after the 6 years are up? or does it stay legal till 2014?

cheers fnq

The battery GME waranty is for 6 years (whether from manufacture or purchase, not sure). On the side of the EPIRB is written, inside a battery symbol "Replace after use or by Mar 2014"

EDIT: Just read the manual ;D

Battery
Replacement Period: Prior to expiry date marked on case

So I guess untill were told to do so :-/ No expiry on the EPIRB mentioned just the batteries

[FNQCairns]

Thats great news! the old ones were 5 years?? Digital may need much less punch from the batterys to get the job done??. If it is up to 14 years thats a huge difference!! and very economical I might spend a little more on one if the GPS variant has the same expiry.

cheers fnq

[subzero]

Beacons operating at 406 MHz and 121.5 MHz are compatible with the Cospas-Sarsat System; however, the operational capabilities of the System are different for these two types of beacons.

An analogue 121.5 MHz distress beacon is a small electronic device that emits a radio signal to help rescue authorities locate your position in a life-threatening emergency. The signal is picked up by polar-orbiting satellites and aircraft monitoring the 121.5 MHz frequency.

These devices, when detected by satellite narrow your position down to a 20 square kilometer region. Aircraft can home on in on beacon signals leading them directly to the target. Detection takes an average of 90 minutes but can be up to five hours.

The 406 MHz distress beacon emits both an analogue and digital signal. The digital signal carries a code which identifies the beacon while the analogue signal is to enable aircraft to home on location. That digital code can be cross referenced with a database of registered 406 MHz beacon owners held at AMSA which identifies who is in trouble and what type of craft they are in. This enables the search and rescue authorities to tailor a response to the emergency situation.

A 406 MHz beacon narrows its position down to 5 square kilometers. This can be reduced to just 120 meters if the beacon includes a Global Positioning System. Detection of 406 MHz beacons can be instantaneous if a geo-stationary satellite is positioned over Australia.

__________________________________________________ ______________


406 beacon Signal type
Digital
Coverage
The entire globe
Identification
406 beacons have a unique identification code which is part of it's signal.
When properly registered with the Rescue Coordination Center, Australia, the unique code provides information about the boat or aircraft, or person carrying the beacon.This includes the owner’s emergency contact and the country of registration. This also allows false alarms to be resolved with a radio or phone call.
Alert time
The 406 signal may be received within seconds by Geostationary satellites.
Location
Accurate to 5kms. Some 406 beacons use Global Positioning System (GPS) and have an accuracy of 120 meters. An accurate location can be determined with the pass of 1 satellite 95% of the time.
Rescue time
If the 406 beacon is registered, it will enable rescuers to know more about who you are, where you are, what your boat/plane looks like, and your emergency contact. This saves time, and therefore helps rescuers to act more quickly.
Signal Power
5 Watts

__________________________________________________ _______________


121.5 Signal Type
Analogue
Coverage
Australian land mass and about 900 to 1500 km from the coast.
Identification
121.5 beacons are anonymous. They don't tell rescue authorities who's in trouble, or even what's in trouble.
Only about 3 in every 100 alerts are genuine. The rest come from:

* Accidental & malicious activation
* Faulty beacons
* Aeroplanes
* Power transformers
* Other electronic equipment
* Unusual atmospheric conditions

All alarms must be tracked to the source. False alerts waste the valuable time and resources of rescue organizations and volunteers.
Alert time
Orbiting satellites take 90 minutes on average to receive the signal but it may take up to 5 hours depending on the conditions. Processing the 121.5 signal may take an additional 45 minutes.
Location
Accurate to 20 km
More information is needed to determine the real location. This usually means at least 2 satellite passes &/or independent intelligence is required to determine a location and this takes more time.
Rescue time
Rescuers must wait for confirmation of the beacon’s position before sending a search & rescue team. This takes more time.
Signal Power
0.1 Watt

Future Technology
From February 2009 the international satellite system (called Cospas-Sarsat) will no longer process the 121.5 signal. This will make all 121.5 beacons obsolete.

__________________________________________________ _______________


The above information was taken and edited from http://www.safeboating.org.au

Once activated an epirb will continue to transmit for at least 24 hours.
They will have an expiry date of 5 years from date of sale, manufacture or service. The battery's in epirbs have a large safety margin built in to them to ensure that they will continue to transmit for at least 24 hours, in reality this means at least double the life of the expiry period at least.
Like all equipment carried on vessels, if it is expired or not in a serviceable condition the Police will offer infringement notices.

Cheers Lloyd

[litenup]

The GME battery life is 6 years, so replace battery then. The Pains Wesssex is 5 years, but there's a deal arround where you can get the replacement battery in price you pay. Not too sure about life of unit, guess manufacturer will tell you it needs replacing if stuffed when battery requires replacing. Cheers Pete

[blaze]

often wonder with these new epirbs, or old ones for that matter, when registered to my boat, if when doing desert treks in my 4x4 and needed to activate the epirb if they would take it for real or would they just think what the heck is a boat doing there, false alarm.
cheers
blaze

[FNQCairns]

often wonder with these new epirbs, or old ones for that matter, when registered to my boat, if when doing desert treks in my 4x4 and needed to activate the epirb if they would take it for real or would they just think what the heck is a boat doing there, false alarm.
cheers
blaze

Yeah me too, we take the current one along with us but have not done any full on trips for quite a while now, will be taking the new one with me on land trip irrespective of what the authorites position on that may be.

cheers fnq

PS thanks pete, for the posting the expiry duration, I badly miss-read BLs reply above, I am back to the cheapest one again...o well. Suspect that these units in the real world will be throw aways same as the current one's, once the warrenty/expiry is through.

[Hamish73]

great info as always LLoyd :thumbup:
I just got a 'new to me' boat and it has a new GME MT300 and a old GME MT250C with an expired battery. Test function works. Anyone who wants it can have it for free. You'd have to imagine a battery replacement would be less than a complete new unit.

[subzero]

The authorities will respond to an epirb no matter where it is used even if its registered to a boat on the water. (Or not registered as the case will be with a 121.5/243 epirb)
So if you take your epirb with you to the interior, then eventually they will find you.
Land, air and marine epirb's are all detected by the same Satellites and aircraft, they all use the same frequency(s). The only difference between the epirbs is the environment they are designed to work in and how they are designed to work. (A marine epirb has a lanyard attached, will often have a strobe light attached, is buoyant, I would expect but dont know for sure that it will transmit for longer as space for batterys are not such an issue as with the little PLB's used by treckers, will have far superior security from water ingress and is designed to work best bobbing around in the ocean using reflected signal from the water plane as well).
121.5 epirbs are generally picked up by orbiting satellites as opposed to geostationary satellites and the path of their orbits is fixed to cover the most populated areas. (Travel the globe about every 100 minutes from memory). A 121.5 epirb will need 2 passes to get you and will also require to see a Local User Terminal and yourself at the same time otherwise it cant download the info as being analogue it cant store the info until it sees a LUT. (The digital do). I would still suspect that you would be located fairly quickly just the same though.

Cheers Lloyd

[blaze]

I would like to think that would happen Lloyd but do you remember the one that went off in mcqauriry harbour on the west coast of tassie and they deemed it to be on land and didnt search
cheers
blaze

[subzero]

Gidday Blaze, haven't heard about the situation you mention. It is possible that if it is a 121.5 epirb then because of its location it was decided that the transmission may have been a spurious one. (I don't know the answer for sure).

This is taken from the AMSA web site found athttp://beacons.amsa.gov.au/Beacon_monitoring/Bushwalkers_PLBs.asp

There has been some discussion on one or two of the bushwalking type chat pages about the use of PLBs - often referred to as EPIRBS, the term used for marine beacons - and the likely action, or inaction, that RCC Australia takes.

To set the record straight, all distress alerts received from the Cospas-Sarsat satellite system are treated as one of the 3% real distress situations until proven otherwise.

It is true that approximately 97% of alerts from distress beacons are non-distress alerts but this does not mean that alerts are not followed up. The actions taken depend on the frequency that the alert is received on. If a 406 MHz alert is detected, we know that it is definitely a distress beacon because we receive the unique identifying code that can be decoded to provide ownership information. Once received, contact can be made with the owner or a nominated 24 hour contact to ascertain the situation. Hence, a false alert can usually be sorted out with a phone call and little or no fuss. Importantly, scarce SAR assets need not be deployed for a non-distress situation.



On the other hand, an initial alert received on the 121.5 MHz frequency presents a more complex problem. A 121.5 MHz alert is anonymous and may even be caused by interferers and other extraneous system generated signals. Even if from an analogue beacon operating on 121.5 MHz, we have no way of knowing whose beacon it is or the exact position of the beacon. Once the SAR Officer assesses that the alert may be generated by a distress beacon, he seeks further intelligence. Firstly, Air Traffic Control services are contacted to alert aircraft in the probable areas to listen on 121.5 MHz (the aviation distress frequency) in an attempt to hear the beacon. Often, an aircraft will hear the beacon before a second satellite passes over the area and the position is then resolved. In addition, the other SAR authorities responsible for the areas around the two unresolved positions are contacted to see if there are any operations in progress that might account for a beacon alert. The satellite system will no longer pick up alerts from 121.5 MHz beacons from 1 February 2009. Although aircraft will still be able to detect the beacons, very few listen on the frequency all the time and you would need to be under a major flight route to be detected.

Once the position is resolved assets are dispatched to home on the signal and, hopefully a successful rescue follows.


Australia is one of a small number of countries with the Mission Control Centre for the Cospas-Sarsat system located in the Rescue Coordination Centre and operated by one of the Search and Rescue Officers on watch. These officers are very astute when it comes to discerning between system derived false alerts and alerts derived from a beacon.

Under no circumstances should people believe that no action is taken on an initial distress alert.

The answer is "Switch to 406". The newer technology being introduced means the price is coming down without detriment to accuracy or the other superior characteristics that the 406 MHz beacons have over the 121.5 MHz units.

[subzero]

Something else I should highlight that I didn't earlier is that when I was quoting accuracy of the 2 types of epirb, they mention 5 square km for the 406 epirb and 20 square km for the 121.5 epirb. These are huge areas to cover from the water in a search and not really all that practicable either. Hence the need to use the services of Aero Rescue Services Dorniers and Rescue Helicopters to locate people in distress. The Dorniers cost AMSA or the Water Police budget $23,000-00 an hour to search and the last time I heard the Rescue helicopters were in the area of $3 to $4 thousand an hour to operate.
Big bucks, but what price a life.
I have tried NOT to offer opinions as the facts really do speak for themselves.... but why the hell would anyone want to buy a 121.5 epirb anyway?

AeroRescue web site http://www.aerorescue.com.au/locations.html

Rescue 500 web site http://www.emergency.qld.gov.au/aviation/

Cheers Lloyd

[blaze]

Hi Lloyd
You are right that it was the older 121.5 epirb BUT. I think there has been major changes because of that incedent. I still have this horrible picture in my head of some dead beat in an office somewhere deciding that, oh that epirb is registered to fred and his boat is mary and there is no way that boat could be in trouble in the middle of the canning stock route, must be a false alarm. I havnt upgrade yet and will be soon, it would be nice to know that I could register my new epirb for all intended uses.
Thank you again for all the valuable information you post for the benifet of others
cheers
blaze

[rumy1]

Even though the initial price tag is dearer for the 406 than the 121, it does work out cheaper in the long run to buy the 406 !!!

When dollars count !

[Black_Rat]

Even though the initial price tag is dearer for the 406 than the 121, it does work out cheaper in the long run to buy the 406 !!!

When dollars count !

The 121 is going for around $160 the 406 is going for around $400.
Given the 121 is due to be become obsolete in 2009 and the 406 will cost you the same in the long run, I can't see the reason for not buying a 406 long term :)