M538-BS(Base Station)
Operating instructions
NOTICE: All persons shall maintain a minimum of 35 cm separation distance when transmitting in
order to meet the Maximum Permissive Exposure level of 0.2mW/cm
2
.
1. Power Supply: The M538-BS is powered by a transformer that will convert from 120 volt AC
to 12 volt DC, with a current capacity of 900mA.
2. Function:
A. Transmit and receive. The M538-BS will operate as a transceiver, meaning it will both
transmit and receive messages from other MURS radio units. The M538-BS is equipped to
operate on 5 channels, with 38 sub channels. In order to communicate with another MURS
radio, the channel and the sub channel must be set alike. The M538-BS also has 4 separate
call tones that can be used to page other users before starting a conversation. The M538-BS
can also receive an alert signal from the MURS ALERT transmitter. This will notify you of
activity at the location of the MURS Alert Transmitter.
B. LCD Display. The LCD will display channel, CTCSS, Tone, TX, RX, Lock Icon(**), and Alert
Icon(**). When the base station is powered up, it will return to the same channel, CTCSS, and
tone that it had when it was turned off.
C. Earphone. The M538-BS is equipped with a jack for an earphone.
D. Relay Function. The red and black push button terminals on the back of the base station are
a Normally Open (NO) relay. The relay will make closure for several seconds when an alert
signal is received from the MURS Alert transmitter. The relay has a capacity of 5A @ 28V DC.
E. Operating range. The M538-BS is capable of communicating up to 2 or more miles. This will
vary depending on the local terrain.
3. Operation:
A. ON/OFF/Volume. With the transformer plugged into an outlet, you can turn the power on or
off by rotating the volume dial on the left side of the base station. This will also control the level
of the volume.
B. Changing Channels. You can select the proper channel by pressing the up or down key.
The lock Icon(**) must be deactivated before you can change the channel.
C. Sub Channels (CTCSS). You can select the proper sub channel by pressing the mode
button once. This will cause the CTCSS display to flash. You can then select the proper sub
channel by pressing the up or down key. The lock Icon(**) must be deactivated before you can
change the sub channel.
D. Call Tone. You can select between 4 different call tones. You can select the proper call tone
by pressing the mode button twice. This will cause the Tone display to flash. You can then
select the proper call tone by pressing the up or down key. The lock Icon(**) must be
deactivated before you can change the call tone.
E. Lock. The lock icon(**) will indicate that the unit is locked and the channel, sub channel and
tone will not be able to be changed. To lock the unit, press and hold the MODE button for 2
seconds. To unlock the unit, press and hold the MODE button for 2 seconds.
F. PTT. The PTT (push to talk) button is used so that you can send a message to another unit.
Simply press the PTT button and speak with a clear voice into the base station. When you are
done speaking, release the button. When the PTT is pushed, the TX display will show on the
