Linear Amplifier Interfacing - Yaesu FT-857 Operation Manual

I
NSTALLATION
The FT-857 provides the switching and drive-control lines required for easy interfacing to
most all commonly-available amplifiers sold today.
These include:
r The Antenna Jacks ("HF/50MHz" and "144/430MHz");
r A T/R control line (open circuit on RX, closure to ground on TX); and
r A negative-going ALC jack (control voltage range: 0V to –4V DC).
r When interfacing to the VL-1000 Solid State 1 KW Linear Amplifier, the optional CT-
58 Interface Cable provides for easy interconnection (requires that the Menu Mode No-
020 [ CAT/LIN/TUN ] setting changes to "LINEAR").
The rear-panel CAT/LINEAR jack is an 8-pin, miniature DIN type, with the "TX GND" pin
providing a closure to ground on transmit, for T/R control of your linear amplifier. The ACC
jack is a miniature stereo type, with external ALC input capability on the tip connection. The
main shaft is the ground return. The ring connection of the ACC jack, when closed to ground,
places the FT-857 into the transmit mode, and sends a steady CW carrier, for amplifier (or
antenna tuner) adjustment purposes.
Note that some amplifiers, particularly VHF or UHF "brick" amplifiers, offer two methods
of T/R switching: application of +13V or a closure to ground.
Be sure to configure your amplifier so that it switches via a closure to ground, as provided
CAT
by your FT-857's
plifiers use "RF Sensing" to control their relays; if yours is in this category, you may then use
the T/R control line from the "TX GND" pin
CAT
/LINEAR jack for control of your
of the
HF linear amplifier, and RF sensing for your
VHF or UHF amplifier.
16
L A
INEAR MPLIFIER
/LINEAR jack ("TX GND" pin). Alternatively, many of these am-
CT-58 BAND DATA Cable
I
NTERFACING
VL-1000
ANT 1
REMOTE
ON
OFF
ANT 2 BAND DATA 1
BAND DATA 2
CT-58 ALC Cable
FT-857 Operating Manual
INPUT 1
PTT 1
PTT 2
INPUT 2
ALC 1
CONTROL
ALC 2
DC48V IN
GND