Zartek ZA-720, User Manual, Page: 8 / 15

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BASIC OPERATION
Power ON/OFF
Turn the Power Knob clockwise to switch on the radio; you will hear an On
sound and a voice message will indicate the current channel number. Turn
counter-clockwise to switch off the radio.
Adjust the Volume
Hold in the side “Monitor” or “Squelch Off” button to listen the background
noise, then turn the On/Off knob to increase or decrease the volume.
Select a Channel
Turn the Channel Selector Knob clockwise to change the channels from 1 to
16. Your radio will report the channel number.
Refer to the factory channel settings when linking your radio to other radios
as it may be necessary to reprogram or adjust the frequency / sub tone to
match.
Transmit
Keep pressing down the PTT key and speak directly into the microphone
hole (MIC). Hold the radio about 2.5cm to 5cm from your mouth. The radio
should be held so that the antenna is vertical. Speak slowly loud and clear
into the radio for a good signal to be received.
Receive
Release the PTT key to receive a call and adjust the volume if needed.
Monitor
The squelch circuit in the transceiver mutes the speaker automatically,
when no signals are present so you will not hear background noise. Hold in
the side button to Monitor a frequency by deactivating the squelch. This is
useful when you want to adjust the volume level, or when you need to hear
a weak signal.
Communication Range
Range will depend on the type of terrain that you are communicating across.
The ZA-720 uses the UHF (Ultra High Frequency) band and will be subject
to similar obstacle interference as cellular phones. The radio works indoors
as well as outdoors. Typical rough estimate ranges for different terrains are:
y
Indoors or Shopping centre 300m-1200m,
y
Building 5-30 stories,
y
City centre & dense bush 500m-2km,
y
Residential & over water 2-6km,
y
Farmland 3-7km,
y
Top of mountain or building (line-of-sight) 10-30km.
When you press the PTT talk button a signal is transmitted and the signal
floods the area in all sideway directions. The signal travels in 3 different
ways:
1) Penetration: The signal can go through materials such as wood, plastic,
cement and fabric. The denser the material or more built up the environ-
ment the weaker the signal will become. The signal cannot go through
solid metal or very large solid land structures such as a hill or mountain.
Metal acts like a shield and that is why the performance from the inside of
a vehicle will be less than from outside.
2) Reflection: The signal cannot go through metal or very large structures
such as a hill or mountain, but it can bounce off (like a mirror), go around
and reflect in other directions as well. This happens at the speed of light.
3) Line-of-sight: Line-of-sight is when there are no obstructions in the path
between the communicating parties. The higher up you go the further you
can see, so the larger the line-of-sight distances will be. Generally you
can talk to wherever you can see, which is why the coverage in a valley
is much less than the coverage from on top of a hill.
Ensure that there is nothing blocking the antenna. The less metal in close
proximity (0-2m) the better the range. There may be external interference
from electrical equipment (power lines or factories) or natural causes (mois-
ture in the air or storms) that may vary depending on the location and the
weather.