Yaesu FT-920 Operating Manual page 16

ceivers, as the ALC voltage may be generated
because of amplifier mis-tuning not related to
an excessive-drive condition. With amplifiers
deriving their ALC voltage in this manner, we
recommend that you not connect the ALC line,
and rather let the amplifier's protection circuitry
manage its ALC requirements internally.
One useful alternative to ALC interconnection may
be considered: by entering Menu Item(s) U-49 and/
or U-50, you may define the maximum power output
for the FT-920. So if your amplifier never requires
more than 50 Watts of drive, just set the maximum
power output to "50" via the menu system, and you
will not have to worry about over-driving your ampli-
fier. And since the power output may be set indepen-
dently for each antenna port (use Menu Item U-49
for Antenna A, and U-50 for Antenna B), you may
lower the power output on a port connected to your
amplifier while retaining the full 100 Watts on the other
antenna port.
Interconnection with QSK Amplifiers
If using a Yaesu FL-7000 amplifier, connect the (op-
tional) cable CT-11 from the transceiver B
the amplifier's ACC-2 jack. This provides automatic
band selection for the linear, as well as QSK Tx/Rx
switching control and sequencing. Also connect an
RCA-to-RCA patch cord (Yaesu Part #T9101296 -
14
supplied with the FL-7000) from the amplifier's ALC
jack to the transceiver's E
an RF coaxial jumper (Yaesu Part #T9100980 - also
supplied with the FL-7000) from the transceiver's
antenna jack (A or B) to the amplifier's RF I
If using another manufacturer's QSK amplifier, and if
it meets the 15 VDC/100 mA limitation for transistor
switching described previously, connect the Tx/Rx
switching line for the linear to Pin 2 of the B
and use Pin 3 for the shield of the cable. If the ampli-
fier provides a closure to ground to confirm that its
relays are properly seated, this "exciter-enable" line
may be connected to Pin 8 of the B
The B
AND
connector. When a suitable plug (Yaesu Part
#P0090160) is inserted into the B
the interlock which, in the case of the FT-920, grounds
Pin 8. If no exciter-enable line is provided by your
amplifier, connect a jumper between Pin 8 and Pin 3
(Ground); if you do not, the FT-920 will not allow it-
self to transmit.
If your QSK amplifier requires the exciter's control
jack to
AND
circuits to switch more than 100 mA, or uses more
than 15 VDC for Tx/Rx relay switching, you will have
to provide a suitable external interface transistor, con-
trolled by Pin 2 of the B
ALC jack, and connect
XT
AND
jack is a specialized, interlocked 8-pin DIN
AND
jack.
AND
FT-920 Operating Manual
jack.
NPUT
jack,
AND
jack.
jack, it opens