Page 4
VL-1000 Operating Manual
connections labeled T
X
G
ND
on the rear panel
of the transceiver; do
not, however, use the
transceiver’s P
TT
jack, as it was designed for
PTT
input (via a footswitch, etc.), not for am-
plifier control.
Automatic Amplifier Tune-Up
If you connect the supplied control cable
between the transceiver’s P
TT
or R
EMOTE
jack
and the VL-1000’s BAND-DATA 2 jack, the
transceiver will automatically transmit when
you press the amplifier’s front panel F SET key
(make sure that the M
ODE
switch of the trans-
ceiver is set to CW, RTTY, or some other con-
tinuous mode, and set the D
RIVE
or R
F
P
WR
control fully clockwise, if you want to perform
antenna tuning). To accomplish this function,
pin 11 of the BAND-DATA 2 jack closes the
transceiver’s P
TT
or R
EMOTE
jack to ground, thus
placing the transceiver in the transmit condi-
tion.
Automatic Amplifier Tune-Up
using FT-1000MP Transceiver
When using the VL-1000 in conjunction with
the FT-1000MP transceiver, the front panel F
SET key may be used to initiate an automatic
tuning procedure for the amplifier. In order to
accomplish this, Menu Item 7-9 on the FT-
1000MP must be set to “
KEYER ” (which is its
default value), and a control cable must be con-
nected between the FT-1000MP’s R
EMOTE
jack
and the VL-1000’s BAND-DATA 2 jack. The
required wiring for this cable is shown below.
Installation
Antenna Connections
As many as four HF or 50 MHz antennas
may be connected to the rear panel Antenna
jacks, labeled ANT 1 ~ ANT 4. The antenna to
be used on a particular band will be memo-
rized once you make the selection manually
via the front panel ANT switch. See the “
Op-
eration
” section of this manual for more de-
tails.
ALC Connections
The VL-1000 provides negative-going ALC,
which provides a negative voltage to the ex-
citer which begins to appear when sufficient
drive power from the exciter is being received;
the voltage becomes of greater (negative)
magnitude if the drive is increased, so as to
prevent overdrive of the amplifier. The voltage
range provided from the VL-1000 is 0 to
-
10
Volts DC, and this is compatible with all Yaesu
transceivers as well as many exciters of other
manufacture. At 1000 Watts of output power,
the typical voltage generated for use with
Yaesu transceivers is about
-
4 V DC.
The ALC cable must be connected be-
tween the transceiver and VL-1000 to
prevent overdrive of the amplifier, and espe-
cially to facilitate the proper operation of the
protection circuitry if sudden antenna system
problems should cause the SWR to rise to dan-
gerous levels.
PTT Connections
These jacks, labeled PTT 1 and PTT 2, ac-
cept T/R control signals from your exciter.
Grounding the center pin of one of these PTT
jacks will cause the amplifier to be placed in
the “Transmit” mode.
These jacks utilize a positive voltage (
+
5V
DC) at very low current (10 mA maximum), so
they are compatible with most open-collector
NPN transistor amplifier control circuits in
modern transceivers. Mechanical relays may
also be used, so long as they are “floating”
contacts that do not apply a voltage to the VL-
1000’s PTT jacks. On Yaesu transceivers, use
either the transistor or relay (Normally Open)