Broadcast Electronics AM-2.5E, User Manual

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2-20
2-83. Emergency Off Indications. The emergency off indicator provides a signal to indicate
when the transmitter is operated to off by any condition or event other than the use of the
off switch. These conditions/events include: 1) an overcycle off condition, 2) a power sup
ply emergency condition, or 3) an open interlock condition. A power supply emergency con
dition is when all the power supplies in the transmitter encounter faults. The emergency
off indicator is located at J2-24. The indicator will go LOW (0 volts dc) to indicate when an
emergency off condition is encountered.
2-84.
WIRING.
2-85. Wiring consists of connecting audio, the RF transmission line, and ac power to the trans
mitter. Refer to the following text and connect the wiring to the transmitter.
2-86.
AUDIO INPUT CONNECTION.
The AM-2.5E and AM-5E transmitters are equipped
with electronically balanced 600 Ohm left and right channel audio inputs. The audio in
puts are located on the transmitter top-panel at J3 (refer to Figure 2-8). The inputs are
designed to accept a +10 dBm signal at 600 Ohms.
WARNING
WARNING
ENSURE PRIMARY POWER IS DISCONNECTED BE
FORE PROCEEDING.
2-87. Audio is interfaced to the transmitter by: 1) selecting the appropriate cable and 2) connect
ing the cable to the terminals of 9-pin D-type connector J3. J3 is located on the transmit
ter top-panel. To interface audio to the transmitter: 1) use Belden 8760 cable or equiva
lent and 2) refer to Figure 2-8 and connect the audio to the transmitter as follows:
1. Connect the plus signal line to the + terminal.
2. Connect the minus signal line to the - terminal.
3. Connect the shield to ground at the audio source end.
2-88.
EXTERNAL STEREO RF INPUT.
The transmitter is equipped with an external stereo RF
input on the transmitter top-panel (refer to Figure 2-9). The input is designed for the con
nection of an external stereo generator or reference oscillator with a signal level from 5 to
15 volts peak-to-peak. If an external stereo signal/reference is to be applied to the trans
mitter, connect the signal to the EXTERNAL RF INPUT connector on the transmitter
top-panel and program jumper P7 on the exciter circuit board in position 1-2.
2-89.
AM-2.5E/AM-5E RF TRANSMISSION LINE CONNECTION.
The AM-2.5E/AM-5E
transmitter RF output connection is located on the transmitter top-panel (refer to Figure
2-9). The AM-5E requires 7/8 inch transmission line with a 7/16 male DIN connector.
The AM-2.5E requires 1/2 inch transmission line with a 7/16 male DIN connector. To con
nect the RF transmission line to the transmitter, refer to Figure 2-9 and connect the 7/16
male DIN type connector to the RF OUT connector on the transmitter top-panel.
2-90.
EXTERNAL INTERLOCK.
The AM-2.5E/AM-5E is equipped with an external interlock
such as for a test load. The interlock will turn off the transmitter RF output when opened.
The interlock is located at J1-24 and J1-25 on the transmitter top-panel. Refer to
External Interlock Input and Int5v in the REMOTE CONTROL section of the
preceding text and perform the procedures to connect equipment to the transmitter exter
nal interlock.
2-91.
MODULATION MONITOR.
The modulation monitor connection is located on the trans
mitter top-panel. Refer to Figure 2-9 and connect the modulation monitor to the MOD
MONITOR SAMPLE OUTPUT receptacle.