Interfacing To Other Linear Amplifiers - Yaesu FT-991 Operating Manual

i
nsTallaTion and
i
144/430MHz Antenna
DC 13.8 V
n
ote
 The TX GND OUT pin (pin 2) of the TUN/LIN jack
is a transistor "open collector" circuit. It is capable of
handling positive relay coil voltages up to +60VDC
at 200 mA or +30 VDC at 1 A. If you plan to use
multiple linear amplifiers for different bands, you
must provide external band switching of the "Linear
Tx" relay control line from the "TX GND OUT" line
at the TUN/LIN jack.
 The specified range for ALC voltage to be used with
the FT-991 is 0 to -4 Volts DC.
 Amplifier systems utilizing different ALC voltages
will not work correctly with the FT-991, and their
ALC lines must not be connected if this is the case.
Page 12
i
nTerConneCTions
o
nterFAcing to
Coaxial Cable (50Ω)
Connect to "INPUT" of the linear amplifier
HF/50MHz Antenna
Linear Amplifier Connection Cable
(Option: T9207451)
l A
ther ineAr MpliFierS
i n !
MportAnt ote
 Do not exceed the maximum voltage or current rat-
ings for the "TX GND OUT" pin (pin 2) of the TUN/
LIN jack. This line is not compatible with negative
DC voltages, or AC voltages of any magnitude.
 Most amplifier control relay systems require only
low DC voltage/current switching capability (typi-
cally, +12V DC at 25 ~ 75 mA), and the switching
transistor in the
such amplifiers.
F T-991 O
FT-991 will easily accommodate
M
peraTing anual