System Description Chapter 2

500-Watt VHF Low Band Transmitter Chapter 2, System Description
325A, Rev. 0 2-10
Table 2-11. VHF Amplifier Tray Remote Interface Connections with the A/V Input
and Remote Interface Assembly
FUNCTION REMOTE JACK/PIN
NUMBER
INTERFACE TYPE
Forward Output Power (A6)
VHF Amp
J10-1
Forward Output Power (A6)
Rtn
J10-2
1V full scale at 1kΩ source
resistance
Reflected O/P Power (A6)
VHF Amp
J10-3
Reflected O/P Power (A6)
Rtn
J10-4
1V full scale at 1kΩ source
resistance
Forward Output Power (A7)
VHF Amp
J10-6
Forward Output Power (A7)
Rtn
J10-7
1V full scale at 1kΩ source
resistance
Reflected O/P Power (A7)
VHF Amp
J10-8
Reflected O/P Power (A7)
Rtn
J10-9
1V full scale at 1kΩ source
resistance
2.4 AC Input
The transmitter needs an AC input of 220
VAC at 40 amps connected to it in order
to operate. The 220 VAC input connects
to (A2) the AC distribution panel in the
upper middle rear of the cabinet. The
panel contains the terminal block TB1
that connects to the 220 VAC.
The AC distribution panel contains four
circuit breakers that supply the AC to the
rest of the transmitter. The input AC is
connected to the main AC circuit breaker
CB1 (40 amps) that distributes the 220
VAC to the terminal block TB2. TB2 has
three MOVs, VR1, VR2, and VR3,
mounted to the terminal block: one MOV
is connected from each leg of the input
AC to ground and another is connected
across the two legs. The input AC is
wired from TB2 through three circuit
breakers, CB2, CB3, and CB4, to the rest
of the transmitter. CB2 is a 10-amp
circuit breaker that supplies the AC
voltage to the IEC outlet strip (A2-A1)
that is connected into the VHF exciter,
the (optional) receiver tray, and any
other optional accessories. CB3 is a 20-
amp circuit breaker that supplies AC
through J5 to the (A6) VHF amplifier
tray. CB4 is a 20-amp circuit breaker that
supplies AC through J6 to the (A7) VHF
amplifier tray. When the VHF exciter
circuit breaker is switched on, +12 VDC
is supplied to that VHF amplifier tray for
the operation of the LED status indicators
in the tray.