MR 109–( ) OPERATION MANUAL
T01008-MRR-0000
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6.6. Beacon
Autonomy
The MR109 has been designed to operate, after 5 years storage at ambient temperature (lower than
25°C), in the active mode for more than 25 hours at a temperature of -20°C.
In order to save battery power the number of self tests shall be limited to one per month, over 5 years.
While operating at -20°C the MR109 will transmit the 406.028 MHz and 121.5 MHz for 25 hours. After
this time the MR109 will transmit only on the homing frequency: 121.5MHz for an additional 10 hours.
VERY IMPORTANT NOTE: at temperatures below -20°C the battery will be affected and the du-
ration of normal operation will be reduced. Therefore the user must note that lower tempera-
tures shorten the transmission time.
6.7.
Integral GPS receiver
The integral GPS receiver is an 8 channel satellite receiver allowing acquisition of global position
within the first 5 minutes of beacon activation. However, be aware that the average time to obtain a fix
is dependant on the beacon location and terrain configuration.
In order to obtain a fix, the beacon shall be operated as described §6.5.2., with care that the sky
clearance is as wide as possible.
The MR109 is programmed to attempt to obtain a fix every 20 minutes, therefore the GPS receiver
should be automatically turned off during periods of 15 minutes in order to save battery power.
Every time the GPS receiver obtains a fix the buzzer will beep shortly 3 times.
The status of the GPS position encoded in the digital message of the 406.028 MHz is indicated by the
LED and the buzzer (see § 6.5)
