5314027928

8311)-115 l*'M Trnnsmiller

For broadcasters requiring Iow power FM transmitters, Collins now offers an improved version of the popular 2-kW 831D-1, the 2.5-kW 831D-1B. With this increased power level. a morę realistic transmitter/antenna combination may be used to provide authorized power leve!s.

The 831 D-1 B is completely solid State except for the finał amplifier tubę. Using a high^ain 5CX1500A, the trans-mitter directly amplifies a composite rf signal from the exciter, thus eliminating extra stages and components.

As in all Collins FM transmitters, the 2.5-kW 831D-1B is equipped with the dependable 310Z solid State exciter to deliver a signal that is far above standards set by the Federal Communications Commission. In a stereo application, this Collins transmitter/exciter combination will provide excel-lent stereo performance with a minimum separation of 35 dB guaranteed.

Featuring vertical parts layout and removable panels, the 831 D-1 B offers truły outstanding accessibility for mainte-nance and ease of installation. The entire transmitter is cooled by a high capacity blower and filament regulation that assures long tubę life, and many hours of trouble-free operation. To provide further dependability. the power supply is completely solid State. These features make day to day operations simply a matter of routine maintenance.

Altitude ........... Operating 7500 ft at 30°C

Nonoperating 10,000 ft

Power Source......... 200 to 250 volts ac 50/60 Hz

1-phase. Available taps on trans-formers are for 200. 210, 220, 230. 240, and 250 volts

Permissible Linę Voltage

Variation........... 15%.

Power Requirements ..... Nominał 2.5 kW output requires

4.9 kVA at 0.90 power factor.

Size.............. 69" (175.2 cm) H; 41" (104.1

cm) W; 22-3/4" (57.8 cm) D.

Weight ............ 850    Ibs (386 kg)

831 D-1 B.......... FM Transmitter.    2.5 kW

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As delivered, the 831 D-1 B is completely assembled and factory tested on the customer's frequency and power setting. A complete set of test data is supplied on each unit to aid the station engineer in setting up parameters of operation. For shipment, onły a few components are removed, but are easily reinstalled for operation. All panels

and access doors are interlocked for safety, and a grounding 831D1B fm Transmitter rod is supplied for maintenance procedures.

8311)-1 li speciticalions

Output Power.........

Output Impedance......

Frequency Rangę.......

Frequer>cy Stability......

Modulation Capability.....

Audio Input Level ......

Audio Frequency Response . .

Audio Frequency Distortion . .

Stereo Separation.......

Harmonie Attenuation . . . . FM Noise Level........

AM Noise Level........

25 kW

50 ohms, vswr 2:1 maximum

88 to 108 MHz

±1000 Hz

±100 k Hz

10dBm ±2dB

Complies with FCC standard pre-emphasis curve

Monaural: 1% PTR (typical 0.5% or less) 50 to 15,000 Hz Stereo: Less than 1% 50 to 15,000 Hz

35 dB minimum. 50 to 15.000 Hz (39 dB typical)

80 dB minimum

65 dB below 100% modulation (±75 kHz)

55 dB rms

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