Unbalanced Line Application; Connecting A Low-Level Audio Input; Figure 3 Model Am25Ck Connections (Balanced Line); Figure 4 Model 300Ck Connections (Unbalanced Line) - Federal Signal Corporation D1 Série Manuel D'installation Et D'entretien

Installation and Maintenance Manual
For 25 Vrms line-operated speakers, connect them directly to the balanced signal output of the 300MB.
Remove the labeled jumper from terminals TB1-13 and TB1-14 of terminal block TB1. Connect the
speakers in parallel to the terminals TB1-13 and TB1-14 of terminal block TB1 on the 300MB. Unlike the
unbalanced line output, this output is not switched.
IMPORTANT: This output is to be used only if there are no SelecTone system devices connected to the
unbalanced signal output (across TB1-15 and TB1-16).

Unbalanced Line Application

See Figure 4. For existing SelecTone systems using the 300CK Connector Kit, use the unbalanced signal
outputs on the 300MB. A 300CK Connect Kit is required to connect a 300GC, 300GCX, 300X, 302GC,
302GCX, 302X or 50GC to the unbalanced signal lines. The 300CK properly terminates the signal lines to
the amplifier in the 300GC, 300GCX, 300X, 302GC, 302GCX, 302X and 50GC. Connect the blue wire on
the 300CK to the
wire from the 300MB.

Connecting a Low-Level Audio Input

See Figure 5 on page 13. There is a provision for a low-level, low-impedance audio signal input at the
rear of the 300MB. It is designed to accept a cascaded input from a master CommCenter (TB1-12), but it
also accepts audio from a telephone system, radio receiver, CD player, or tape player. When the
pin (TB2-2) on the cascade input is pulled to circuit ground, audio on the cascade-in signal line is gated
through the CommCenter and output on the signal lines. This input is the lowest priority. The audio-level
input should be 1 Vpp. When cascading units, connect the cascade-out
and ground of the slave unit to the cascade-in
12

Figure 3 Model AM25CK connections (balanced line)

300GC
AM25CK
TERMINAL BLOCK (TB1)
ON REAR OF 300MB
wire from the 300MB. Connect the yellow wire on the 300CK to the
SIG COM

Figure 4 Model 300CK connections (unbalanced line)

300GC
300CK
YEL
TERMINAL BLOCK (TB1)
ON REAR OF 300MB
Model 300MB-SD CommCenter Series D1
300GC
AM25CK
14 13
SHIELDED TWISTED PAIR
SIGNAL LINE TO ADDITIONAL
SELECTONES
300GC
300CK
BLU YEL
16 15
SHIELDED TWISTED
PAIR SIGNAL LINE TO
ADDITIONAL SELECTONES
COM SIG
HI
and
ENABLE SIGNAL
290A7443
BLU
290A7332
ENABLE and SIGNAL
terminals on the master unit.
SIG HI
ENABLE
terminals