Page 8 VX-1700 OPERATING MANUAL
MOBILE MOUNTING
The optional MMB-89 Mobile Mounting Bracket allows
quick insertion and removal of the VX-1700 transceiver
from the vehicle. Complete installation instructions are
provided with the bracket.
Mobile Antenna Considerations
The VX-1700 transceiver is designed for use with any
antenna system providing a 50-Ohm resistive impedance
at the desired operating frequency. While minor excursions
from the 50-Ohm specification are of no consequence, the
power amplifier’s protection circuitry will begin to reduce
the power output if there is more than a 50% divergence
from the specified impedance (less than 25 Ohms or greater
than 100 Ohms, corresponding to a Standing Wave Ratio
(SWR) of 2.0:1). Compliance with this specification criti-
cally depends on the range of frequencies on which opera-
tion will take place, and the design of the antenna(s) in
use.
If your mobile or marine operation requires wide frequency
coverage, the Yaesu YA-007FG or similar mobile whip
antenna may be used in conjunction with the Yaesu FC-
40 External Antenna Tuner. The FC-40 is designed to ac-
commodate a wide variety of whip impedances at the op-
erating frequency, converting these to the desired 50 ohm
impedance via a sophisticated microprocessor-controlled
impedance matching circuit. The FC-40 and VX-1700 pro-
vide memory of antenna matching settings sufficient for
all channels on Memory Bank 1. In marine applications,
the FC-40 is also ideal for the use with a “backstay” an-
tenna or marine mobile whip.
The FC-40 should be located at or near the base of the
antenna, so as to minimize losses and stray radiation. The
short lead-in wire from the whip must be securely bonded
both to the FC-40 and the antenna (whip or wire), and the
FC-40 must be securely bonded to the vehicle or vessel
ground system, which will act as a counterpoise for the
FC-40 and antenna radiating element. Be sure to weather-
proof all outdoor connections thoroughly, especially in
maritime environments.
Complete the installation by connecting the RF coaxial
cable and FC-40 control cable as shown in the pictorial
below. Complete installation instructions are found in the
FC-40 Instruction Manual; follow the manufacturer’s in-
stallation instructions when using a whip antenna other
than the YA-007FG.
For extending the operating frequency range of an antenna
fed with coaxial cable, the Yaesu model FC-30 Antenna
Tuner may also be used. The impedance matching range
of the FC-30 is from 17 Ohms to 150 Ohms. Interconnec-
tion guidelines may be found in the Operating Manual for
the FC-30.
VX-1700
FC-30
INSTALLATION
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