ZA-725 User Manual
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ZA-725 User Manual
13
The ZA-725 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:
Indoors or Shopping centre 300m-1200m
Building 5-30 stories,
City centre & dense bush 500m-2km,
Residential & over water 2-6km,
Farmland 3-7km,
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 environment
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 (car or
4x4) will be less than outside and a external car antenna kit is recommended
to improve communication.
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
(moisture in the air or storms) that may vary depending on the location and
the weather.
BASIC OPERATION
Power On/Off
Turn the Power Knob (also called Volume Knob)
clockwise to switch on the radio; you will hear a “di”
sound and a voice message will indicate the current
channel number. Turn counter-clockwise to switch off the
radio. (see Figure1)
Adjust the Volume
Press the programmed SK1 “Monitor” key or “Squelch
Off” key to listen the background noise, then turn the
knob to increase or decrease the volume. (see Figure2)
Select a Channel
Turn the Channel Selector Knob to select your desired
channel. If the Voice announcement function is enable,
your radio will automatically report the channel No.
where the knob locates. (see Figure 3).
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 (MIC). Hold the radio about 2.5cm to
5cm from your mouth. (see Figure 4). The radio should
be held so that the antenna is vertical.
Receive
Release the PTT key to receive a call and adjust the
volume if needed.
Communication Range
Range will depend on the type of terrain that you are
communicating across.
Figure1
Figure2
Figure3
Figure4
