Reply With Quote1. Keep in mind a PLB (P-Epirb) does not meet marine requirements as the sole unit.
2. In a ditch bag a PLB would be a second choice (and generally more expensive) over a straight marine type Epirb.
It is waterproof, but this is from the manufacturers site and means its probably best for land use compared to one that floats upright and has the aerial sticking upright...
"GPS Antenna Orientation (2797.4 ONLY)
When activated it is critical that you do not cover the front bottom portion of the P-EPIRB with any body part, water, clothing, etc. The GPS Antenna is located under the front bottom portion of the case behind the embossed ACR logo. To ensure proper operation it needs to be unobstructed with a clear view to the sky. Avoid submerging this portion of the P-EPIRB in water if possible, as water will shield and inhibit the GPS receiver and may cause difficulties obtaining LAT/LON coordinates.
406/121.5 Antenna Position
For maximum performance you must deploy the P-EPIRB antenna into the proper position (see figure 2). The antenna will snap into place and be slightly slanted to the side. Be sure the antenna is positioned facing the sky and avoid submerging in water. If afloat employ all means to keep the P-EPIRB out of the water and the antenna dry. For best results it is important to keep the antenna dry and away from the water. Water acts as a detractor from the performance and reduces the P-EPIRB’s effectiveness.
"
1. Keep in mind a PLB (P-Epirb) does not meet marine requirements as the sole unit.
2. In a ditch bag a PLB would be a second choice (and generally more expensive) over a straight marine type Epirb.
Once again I'm a bit confused, I pulled this off the Pains Wessex site,
The standard Fastfind 406 MHz Personal Location Beacon has all the features of the Fastifnd Plus but without GPS.. The 406 MHz frequency provides an alert signal to the rescue services within 90 minutes depending on satelite passes and give a positional accuracy to within 3nm. Once in the vicinity the 121.5 MHz transmitter provides a signal for the rescue services to home-in on. This information is more than sufficient to enable rescue services to find a vessel or individual in distress particularly if equipped with flares and lifejacket light.
I thought that the 406's relayed the information on straight away, not within 90 mins. So if you haven't got a GPS eqipped one you could wait up to 90 mins, same as analogue I guess.
Then with the GPS eqipped one, below, (which i've put in bold) it say's that it also transmits on the 121.5mhz providing a homing signal for SAR. I thought that was the whole idea of getting a GPS equipped one so they find you within 50 metres or so, and not relying on the 121.5mhz?
The Precision 406 GPS EPIRB has been specifically designed to meet the needs of leisure boaters and commercial ship operators alike. The Precision features an internal 12 channel parallel GPS receiver within a compact 406 EPIRB. When activated, the precision GPS 406 EPIRB provides a 406 Mhz alert signal via the COMPAS-SARSAT satelite system. There is a visual indication of GPS acquisition. Precision also transmits on the International Aircraft Emergency Frequency of 121.5 MHz providing a homing signal for the Search And Rescue (SAR) services. A built-in self test facility includes testing of the 406 MHz and 121.5 MHz signal (where permitted) and GPS power up.
GPS equipped is meant to be down to about 5m and 406 5 SQUARE ks I thought
1. The "alert" is almost immediate using stationary satellites, they will know there might be an issue and will confirm this based on the registration details
2. Once "confirmed" as an issue then rescue services are on alert and could be partly dispatched
3. Without GPS it will/could take a short period (using the orbiting sats) depending on the location and relevent satellite coverage to determine an initial position which will then be confirmed by a second independent satellite position.
4. ALL 406 Epirbs have a 121.5mHz homing signal as the 406 signal is not trackable
5. GPS equiped Epirbs will not have an accuracy of 50 metres but certainly very close to the mark
This link was posted some time ago by member TheRealAndy which details dramas with the ACR GPIRB. Makes for interesting reading.Originally Posted by ozscott
http://www.boatus.com/foundation/Fin...39/default.htm
Thank's Chine for digging that up, I was going to pay the extra for the GPS one when purchasing, but now I'm wondering why bother. I love this bit, "Additionally, they plan to offer owners of their GPS-enabled beacons a software and firmware upgrade." where have I heard that line before??
Last edited by fishing111; 24-05-2008 at 08:37 AM.
I hope this clears the confusion;
Important changes to the satellite system
The international council that controls the satellite system, Cospas-Sarsat, decided in October 2000 to cease processing 121.5 MHz analogue signals by satellite on 1 February 2009. From that date only 406 MHz beacons will be detected by satellite. The decision was made to reduce the chronically high false alarm rate from analogue distress beacons.
Currently 97 percent of analogue distress beacon signals are false alarms. A lot of Volunteer Coast Guard money and time wasted.
In the United States there have been cases where pizza ovens and automatic teller machines have been detected emitting an analogue 121.5 MHz signal. As every beacon alert in and around Australia is treated as a genuine emergency until proven otherwise, these false alarms are tying up scarce search and rescue assets such as helicopters. AMSA is concerned that someone at sea in a genuine emergency will get an undersized search and rescue response because search and rescue assets are tied up chasing a false alarm. This has not occured in Australia to date, but the concern by many authorities around the world that it could happen has led to the international decision to eliminate the analogue frequency.
^
The digital beacons transmit an identity code on the 406 MHz frequency that can be cross-referenced with a database of registered 406 MHz beacon owners by AMSA. This database includes phone numbers, next of kin contacts, information on the type of vessel, how many people it usually carries and other vital information that enable the right response to the emergency to be provided. In the case of false alarms, it enables us to make a call to the registered beacon owner to see if he/she is in genuine distress or just has a beacon transmitting by accident. Many maritime false alarms occur because the switch on the distress beacon has been bumped on.
Most significantly however, 406 MHz beacons are detected more quickly and accurately (to within 5 km by satellite compared to 20 km for the analogue beacons) which has an obvious safety advantage. As well, depending on the location of the 406 MHz beacon it may be detected within minutes, compared to the average one hour and 30 minutes it takes to get a confirmed satellite detection from a 121.5 MHz analogue beacon.
Survival - The 406 MHz Distress Beacon
... is smarter, faster, safer. Global accuracy to within 5 kilometres.
A digital signal identifies its owner, is detected faster and your position is pinpointed much more accurately than ever before.
^
406 MHz Distress Beacon - The leader of the pack
Search and rescue teams will in most cases find you faster if you activate a superior 406 MHz beacon. It is detected more quickly than a 121.5 MHz beacon and can be located to within 5 km. If the 406 MHz beacon also has a built-in Global Positioning System, the location can be pinpointed to within 120 metres.
A 121.5 MHz beacon will only narrow your position down to 20 km.
What is a satellite distress beacon?
Satellite beacons take much of the search out of search and rescue. When activated, beacons transmit a signal to the Cospas-Sarsat global search and rescue satellite system which processes the information to obtain a position. This information is relayed to The Rescue Coordination Centre, RCC Australia, operated by AMSA in Canberra.
Beacons come in many shapes and sizes. They include Emergency Locator Transmitters (ELTs) found in aircraft, hand-held Personal Locator Beacons (PLBs) and marine-based Emergency Position Indicating Radio Beacons (EPIRBs).
^
2009 - a change is coming
From February 2009 the Cospas-Sarsat satellite system will no longer process the 121.5 MHz frequency used by most distress beacons. The distress frequency used by the satellite network will be 406 MHz.
Why the change?
RCC Australia detects many false distress alerts from non-beacon transmitters that interfere with the 121.5 MHz frequency and from inadvertently activated beacons. In Australia about 97 percent of the distress alerts detected are false.
False alerts can be resolved quickly with 406 MHz beacons as they transmit a digital signal that identifies the owner. AMSA keeps a register of 406 MHz beacon users and can simply make a phone call to determine if there is a genuine emergency or not.
If there is a problem, a 406 MHz beacon will eliminate much of the guesswork in a search by telling RCC Australia your name, address and the type of boat, aircraft or vehicle you are in.
121.5 MHz beacons are based on obsolete analogue technology that does not support an identifying message. In most cases, when these beacons begin transmitting, an expensive search has to be launched to determine if there is someone in distress.
These searches could divert rescue resources away from a genuine emergency.
^
What should you do?
2009 may seem a long way off, but you should start planning to upgrade now.
If you already have a 406 MHz beacon then you need not worry as long as it is registered. If you are not sure call AMSA on 1800 406 406 and check. You should have your beacon's fifteen character hexadecimal code ready for the database operator.
If you are relying on a 121.5 MHz beacon, you could upgrade when your beacon's battery is due to be replaced or you could simply make the change now. 406 MHz beacons are only slightly more expensive than 121.5 MHz beacons but offer far more features. Regardless of the price, if it saves your life, it is cheap insurance.
^
More information
406 MHz beacon registration advice
Telephone: 1800 406 406
Postal Address:
406/MMSI Registration Section
Australian Maritime Safety Authority
GPO Box 2181
Canberra ACT 2601
Rescue Coordination Centre (RCC)
24 Hour Emergency contact numbers:
1800 641 792 (Maritime)
1800 815 257 (Aviation)
Additional information about the Cospas-Sarsat international satellite system can be found at: www.cospas-sarsat.org
Get a better fix with 406.
Thanks mate - great article - but will the GME one with GPS work - is it worth the extra dough?
The best advise I can offer is the more safety gear on board the better chances of survival are as a skipper or master of the vessel who has the responsibility for other persons on board...
If you have VHF DSC and an EPIRB GPS, you've done the best possible
I guess thats right - one of the epirbs on that test did generally work with its GPS signal...and presumably GMEs should - they know somthing about GPS from the Garmin side of things. I have VHF with DSC hooked up and an EPIRB with GPS would be a nice way to finish it off...and certainly on dry land 4WDing/hiking etc it would be a very accurate safety item.
Cheers
Paul,
I think this particular ACR GPIRB failure was down to a corrosion issue with the antenna and was correctly addressed.
The 406 GPIRB is top shelf and should produce a response time in the order of 5 minutes with regular updates to allow for drift with normal GNSS accuracy......and you also have the 121.5Mhz homing signal as an added security.
The response time on the standard 406 EPIRB is entirely dependant on satellite geometry and number of received signals, the higher the LEOSAR satellites on your horizon then the better the accuracy and response time. The existing satellite configuration should lend itself to a premium 406 response. I query the 90 minute quotation in your other post.
If you can afford it go for the GPIRB although the standard EPIRB will also give you excellent security in our latitudes. The GPIRB is serviced by two geostationary satellites on the east coast (one Indian unit and one USA) for the balance of the australian coast, the one Indian satellite. EPIRBS are serviced by four low altitude polar orbiting satellites which take around 15 minutes to cross your sky.
This new digital technology has generally improved response times over the old analogue system by 45~60 minutes. That is a long time in cold water.
Last edited by Chine; 24-05-2008 at 05:35 PM. Reason: More to say..........
"and presumably GMEs should - they know somthing about GPS from the Garmin side of things"
1. I would not necessarily make that comparison as GME is only the Australian importer/distrubuter for Garmin
2. Actually should rephrase as GME WAS the Australian importer for Garmin products, GME no longer have anything to do with Garmin
3. In any case the GPS side of GME Epirbs would be using third party off the shelf GPS chips as does most other manufacturers
Last edited by SatNav; 25-05-2008 at 10:15 AM.
Chine everything in purple is off the P&W website,
The standard Fastfind 406 MHz Personal Location Beacon has all the features of the Fastifnd Plus but without GPS.. The 406 MHz frequency provides an alert signal to the rescue services within 90 minutes depending on satelite passes and give a positional accuracy to within 3nm. Once in the vicinity the 121.5 MHz transmitter provides a signal for the rescue services to home-in on. This information is more than sufficient to enable rescue services to find a vessel or individual in distress particularly if equipped with flares and lifejacket light.
1. Satellite coverage at present is not all that great as at this point there are no Russian (Cospas) satellites in the system at all.
2. Cospas9 was decommissioned late 2007 and another was shutdown in 2006 sometime. The loss of these satellites (natural planned attrition) have had a direct affect on 121.5 detection since about 2006. 121.5 detection is also currently limited due to Sarsat problems.
3. Russia has plans to launch replacement sats sometime in 2009 (I think?)
4. The Indian sat (Insat-3A) also currently has limited capabilities and it is this Geo Sat that covers Australia.
5. 121.5 detection capability has been steadily going down hill for quite a few years
Last edited by SatNav; 25-05-2008 at 10:25 AM.
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