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The MT250D Power Amplifier is a highly versatile,high-power performer. It delivers
250 watts (rms) at less than 2% distortion and is ideal for use where high power
and backup capability are required. The unit will operate both from 120/240VAC
(50/60Hz),and from a 24-volt battery backup system. It includes a battery saver
circuit which reduces idling power requirements after at least 20 seconds of no
signal. The amplifier complies with UL standards for Fire Protective Signaling
Equipment (UL1711). The front panel power switch is disabled so that the unit
remains on regardless of the position of the switch (an internal jumper enables
the switch for applications where this is desired.)
The amplifier can handle
input from a high-impedance unbalanced source, balanced low-impedance source (requires
accessory transformer), or from a telephone line. The impedance at the Hi-Z input
is 50 kilohms, nominal,and 600 ohms for the Lo-Z input (requires an accessory
transformer). The input sensitivity is 1 volt for full rated output (Hi-Z). The
Lo-Z input sensitivity is 200mV with the input selector switch in the HIGH LEVEL
position,and 70mV with the switch in the TEL LINE position. Provisions are included
for bridging input (requires an accessory transformer). Five output transformer
taps are provided on the rear panel: 12.5V, 25V, 8-ohm, 70.7V and 100V.
A
polarized output receptacle is provided for the 100V output. A low-cut filter
switch and input level control are provided. The amplifier is protected from
overload by fuses on the AC and DC inputs, and by thermal and electronic circuits
(includes a front-panel mounted elec-tronic overload indicator). The amplifier
is housed in a sturdy 11-gauge metal enclosure finished in flat black. The front
panel is designed with predrilled mounting holes for installation in standard
equipment racks.- 250 watts continuous (rms) output for a duration of 250
hours
- Listed under UL 1711 for Fire Protective Signaling Systems, registration
number S2594(N)
- Life Safety features provide capability for 24V customer-supplied
backup battery when primary power fails
- Battery-saver circuit reduces
idle current to a low value after 20 seconds (minimum) of no signal
- Protection
against line surges, overloads, and abnormal heat buildup
- LED overload
shutdown indicator
- Switchable low frequency filter
- Unswitched
AC convenience outlet (300 watts)
- Low impedance balanced input offers
two sensitivity levels using accessory transformers
- Rack mountable in
standard 19" EIA rack; 11-gauge metal housing with flat black finish
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