Figure 2.4 Pacific Crest Uhf/Vhf Base Radio - ashtech Z-Xtreme System Manual

mended, for example the Pacific Crest PDL model shown in Figure 2.4.

Figure 2.4 Pacific Crest UHF/VHF Base Radio

The advantage of a UHF or VHF radio is that radios operating in these ranges can
legally transmit data using high powered transmitters. Though UHF and VHF radios
are affected by line-of-sight obstructions between the base and rover systems, the
increased transmission power of these radios allow for transmissions to push through
more obstructions than other radios functioning at higher frequencies, i.e. spread-
spectrum. Because of the power levels at which these radios function and the fre-
quency they utilize, a license must be obtained from FCC to operate them.
The radio in the rover system is available as a stand-alone component or embedded
in the Z-Xtreme receiver. The advantage of the embedded option is the simplicity of
not having another component with attendant cabling. This option is only available at
the rover. Since the base system must transmit data, the radio at the base is com-
bined with a 35-watt power amplifier. This requires that the radio be external to the
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