User's Manual

2-2
VAC the meter will read a little higher
(3125 VDC).
B. Screen current (Is) - When in this position,
the meter is paralleled with a resistor in
series with the screen supply. This
monitors screen grid current. The upper
limit for screen current is 75 mA.
NEVER OPERATE THE TITAN III IN
EXCESS OF 75 mA SCREEN GRID
CURRENT. A warning zone indicator is
used on the face of the meter to alert the
operator. In addition to the analog meter,
the screen overdrive LED indicates
excessive screen current.
C. Forward power (FWD) - When in this
position, the meter is connected to the
forward port of a bridge circuit at the
antenna output. This measures forward
RF output power. It is, however, more
load dependent than an external
wattmeter. If your antenna is far from
resonance, the accuracy is not as good and
power measurements should be made
externally.
D. Reflected power (REF) - When in this
position, the meter is connected to the
reverse port of the bridge at the antenna
output. Reflected power is read at 1/10
indication scale of forward power (200
watts full scale).
2.2.8 PLATE CURRENT METER:
Full time plate current metering is provided
by the left analog meter.
2.2.9 OVERDRIVE: These two LEDs indicate
grid overdrive conditions.
A. When the screen overdrive LED is lit, the
screen current is approaching or has passed its
limit. Reduce drive from the transceiver
immediately and retune.
B. When the control grid overdrive LED is
lit, the control grid current is approaching or has
passed its limit. Reduce drive from the
transceiver immediately and retune.
2.2.10 WAIT: This LED indicates a 3 minute
warm-up period for the tube at initial power up.
After being turned on for 3 minutes, the wait
LED goes out and the TITAN III can be
placed in the operate mode.
2.2.11 PEAK POWER BARGRAPH:
This meter is connected to the bridge at the
antenna output through an emitter follower
to monitor peak RF output power. When the
red LED is lit, 1500 watts output has been
reached.
2.3 REAR PANEL CONNECTIONS
AND CONTROLS: The rear panel
connections and their functions are
described below.
2.3.1 TRANSCEIVER: This is a standard
SO-239 receptacle designed for a mating
PL-259 plug. RG-58U or similar 50 ohm
coax is required to connect the TITAN III to
the transceiver.
2.3.2 ANTENNA: This is a standard SO-
239 receptacle designed for a mating PL-259
plug. RG-8 or similar 50 ohm coax rated for
1500 watts is required for connection to the
antenna.
2.3.3 KEY IN: This jack is the input for
the TITAN III transmit/receive relay
system. When used with late model TEN-
TEC transceivers, this jack is connected to
the TX OUT connector on the transceiver.
When used with other transceivers, a key or
keyer is connected to this jack for CW
operation.
2.3.4 KEY OUT: This jack is a protected
output from the TITAN III which passes the
KEY IN to the transceiver after all relays in
the TITAN III have closed and it is ready to
transmit. When used with late model TEN-
TEC transceivers, this jack is connected to
the TX EN connector on the transceiver.
When used with other transceivers, this jack
is connected to the transceiver key input
jack.
2.3.5 PTT/VOX: This jack is an input to
the TITAN III transmit/receive relay