Speco Technologies PBM-60 - Manual (Page 6)

6
25V and 70V CONSTANT LINE VOLTAGE CONNECTIONS
(refer to figure 4).
IMPORTANT NOTICE: When the 25V and 70V constant line voltages are used, a line matching
transformer must be used with each speaker. All transformers must be connected in parallel.
HOW TO CONNECT LINE MATCHING TRANSFORMERS IN PARALLEL
(25 VOLT LINE OR 70 VOLT LINE)
ALWAYS CONNECT LINE TRANSFORMERS IN PARALLEL
NEVER CONNECT LINE TRANSFORMERS IN SERIES
S
P
1
S
P
n
S
P
1
S
P
n
25V Transf. 70V Transf.
FIGURE 4
SPEAKER IMPEDANCES:
Output cabling need not be shielded in most cases and should be of sufficient gauge to minimize
losses due to the resistance of the wire over long runs (insertion loss). Cable thinner than 18
gauge is not recommended. Long runs require 16 gauge or heavier.
In some cases, where the output cable is run in close proximity to unshielded intercom cables,
electrical cables, radio transmission antennas or other sources of interference or when the
amplifier is being used for paging from a telephone system, the amplifier may require shielded
output cabling to prevent audio feedback or interference.
PRIORITY PAGE:THE AMPLIFIER FEATURES A VOICE ACTIVATED PRIORITY PAGE CIRCUIT AND
AUTOMATICALLY MUTES ALL PROGRAM MATERIAL (TUNER/TAPE/CD,ETC.) FROM THE
AMPLIFIERS OUTPUT AND PERMITS MICROPHONE # 1 AND THE TELEPHONE INPUT TO
OVERRIDE FOR PAGING ANNOUNCEMENTS.
TELEPHONE LINE: A TELEPHONE LINE INPUT OF 600 OHM IS PROVIDED.
THERE ARE MANY OTHER FEATURES OFFERED. PLEASE READ MANUAL COMPLETELY.