Transcom

 

FM-25K TRANSMITTER SPECIFICATIONS

POWER OUTPUT: 10 kW to 25 kW.

FREQUENCY RANGE: 87.5 to 108 MHz, tuned to specified operating frequency.  Exciter programmable in 50 kHz increments.

RF OUTPUT IMPEDANCE: 50 ohms.

OUTPUT TERMINATION: 3 1/8” EIA flange.

FREQUENCY STABILITY: 300 Hz 0- to 45C TCXO.

TYPE OF MODULATION: Direct Carrier Frequency Modulation.

MODULATION CAPABILITY: 100 kHz.

AC INPUT POWER: 208/240 V, 3-phase, 50/60 Hz and 360/415V, 3 phase, 50/60 Hz, 4-wire.  Power consumption: 40 kW typical.

RF HARMONICS: Suppression meets all FCC requirements.

ALTITUDE: 10,000 feet (3048 meters).

AMBIENT TEMPERATURE RANGE: -20C to +5OC .  Maximum temperature 50C @ sea level, decreasing 2C per 1000 feet (305 meters) to 30C maximum at 10,000 feet (3048 meters). MAXIMUM VSWR: 1.7 to 1.

SIZE: Transmitter cabinet, 34.6" W (87.8 cm) x 71.7" H (182.1 cm) x 31.0" D (78.7 cm).  HV power supply cabinet: 48.0" W (121.9 cm) x 60.2" H (152.9 cm) x 24.2" D (61.5 cm).

FINISH: White, blue and black.

WEIGHT & CUBAGE: (Estimated) Export: 3000 lbs.(1361 kg).  Domestic: 2700 lbs. (1225 kg).  Cubage: 150 cubic feet.

WIDEBAND COMPOSITE OPERATION

COMPOSITE INPUT: One balanced floating input.

COMPOSITE INPUT IMPEDANCE: 2000 ohms resistive.

COMPOSITE INPUT CONNECTOR: Female BNC.

COMPOSITE INPUT LEVEL: 1.0 volt RMS nominal for 75 kHz deviation.

EXTERNAL SCA GENERATOR INPUTS: Up to two unbalanced inputs (optional).

COMPOSITE FM SIGNAL TO NOISE: 80 dB below 100% modulation (reference 400 Hz @ 75 kHz deviation with 75 microsecond de-emphasis, 20 Hz to 200 kHz bandwidth). COMPOSITE HARMONIC DISTORTION: .08%.

COMPOSITE INTERMODULATION DISTORTION: .02% (60 Hz/ 7 kHz 1: 1 tone pairs).

COMPOSITE CCIF INTERMODULATION DISTORTION: All distortion products below 80 dB (reference 14 kHz/15 kHz test tone pair).

COMPOSITE AMPLITUDE RESPONSE: 0.1 dB, 30 Hz-53 kHz.

ASYNCHRONOUS AM SIGNAL TO NOISE: 55 dB below reference carrier AM modulation 100% output power.

MONAURAL OPERATION

AUDIO INPUT IMPEDANCE: 600 ohms, balanced, resistive, transformerless, adaptable to other impedances.

INPUT FILTER: Controlled response low pass filter, defeatable.

AUDIO INPUT LEVEL: +10 dBm 1 dB for 100% modulation at 400 Hz.

AUDIO FREQUENCY RESPONSE: Standard 75 microsecond FCC pre-emphasis curve 0.5 dB, 30 Hz-15 kHz.  Selectable: flat, 25 or 50 microsecond pre-emphasis.

HARMONIC DISTORTION: 0. 15%, 30 Hz to 15 kHz de-emphasized.

INTERMODULATION DISTORTION: 0. 1 %, 60 Hz/7 kHz test tone pair, 4:1 ratio.

CCIF INTERMODULATION DISTORTION: All distortion products down 70 dB (reference 14 kHz/15 kHz test tone pair).

FM SIGNAL TO NOISE RATIO: 80 dB below 100% modulation (reference 400 Hz @ 75 kHz deviation, measured 20 Hz to 200 kHz bandwidth, 75 microsecond de-emphasis).

STEREO OPERATION

TYPE OF MODULATION: Digitally Synthesized Modulation (DSM).

AUDIO INPUT IMPEDANCE: Left and right channels: 600 ohms, balanced, resistive, transformerless, adaptable to other impedances.

AUDIO INPUT LEVEL: +10 dBm, 1 dB for 100% modulation.

AUDIO FREQUENCY RESPONSE: (Left and right) standard 75 microsecond FCC pre-emphasis curve 0.5 dB, 30 Hz-15 kHz.  Selectable: flat, 25 or 50 microsecond pre-emphasis.

INPUT FILTERING: 15 kHz low pass filter, 45 dB rejection at 19 kHz.

OVERSHOOT PROTECTION: Harris patented Dynamic Transient Response (DTR) filter.  Defeatable for test purposes.

AUDIO TRANSIENT RESPONSE: 2% maximum overshoot beyond steady state.

HARMONIC DISTORTION: (Left or right) 0.2% or less, 30-15,000 Hz.

INTERMODULATION DISTORTION: (Left or right) 0.12% 60 Hz/ 7 kHz test tone pair, 4:1 ratio.

CCIF INTERMODULATION DISTORTION: (Left or right) all distortion products down 75 dB (reference 14 kHz/15 kHz test tone pair).

STEREO SEPARATION: 50 dB, 30 Hz-15 kHz; typically 60 dB at midband frequencies.

DYNAMIC STEREO SEPARATION: 48 dB under normal programming conditions.

LINEAR CROSSTALK: - 50 dB.

NON-LINEARCROSSTALK: -6O dB.

76 kHz SUPPRESSION: - 68 dB.

38 kHz SUPPRESSION: - 73 dB.

FM NOISE: (Left or right) 72 dB minimum below 100% modulation.  Reference: 400 Hz, 75 microsecond de-emphasis, 75 kHz deviation, measured 30 Hz to 15 kHz bandwidth.

PILOT OSCILLATOR: Crystal controlled.

PILOT PHASE: Harris patented automatic pilot phasing circuit. PILOT STABILITY: 19 kHz 1 Hz 0 to 50C.

OPERATIONAL MODES: Stereo, mono (left and right), mono (left), mono (right)-remoteable.

SCA OPERATION

MODULATION: Direct FM.

FREQUENCY OF OPERATION: 41 or 67 kHz programmable, any frequency between 25 and 75 kHz on special order. FREQUENCY STABILITY: 500 Hz.

MODULATION CAPABILITY: 7.5 kHz.

AUDIO FREQUENCY RESPONSE: 41 kHz and 67 kHz AC coupled input, 150 microsecond pre-emphasis 1 dB, standard.  Selectable flat, 50 or 75 microsecond pre-emphasis.  DC coupled input: No pre-emphasis: DC to 4 kHz  0.5 dB.

AUDIO INPUT IMPEDANCE: 600 ohms balanced (AC coupled).  Also 2000 ohms DC coupled unbalanced input through rear BNC connector.

AC INPUT LEVEL: +10 dBm,  1 dB for 100% modulation at 400 Hz @ 600 ohms.

DC INPUT LEVEL: 1.0 volt peak for 5 kHz deviation.

INPUT FILTERING: Programmable LPF, 4.5 kHz standard. 3 kHz, 5 kHz, 7.5 kHz selectable.  Low pass filter defeatable. HARMONIC DISTORTION: 0.5%,30-4,500 Hz 5 kHz deviation

INTERMODULATION DISTORTION: 1%, 60 Hz/7 kHz, 1: 1 ratio (audio low pass filter and pre-emphasis bypassed).

FM NOISE: (Main channel not modulated) -63 dB (reference: 100% modulation = 5 kHz deviation at 400 Hz).

CROSSTALK: (SCA to main or stereo sub-channel) -60 dB or better.

CROSSTALK:          (Main or stereo sub-channel to SCA) 57 dB below  5 kHz deviation of SCA with mono or stereo channels modulated by frequencies 30 Hz-15 kHz, SCA demodulated with 150 microsecond de-emphasis.

CROSSTALK: SCA to SCA (41 kHz/67 kHz) - 50 dB demodulated with 150 microsecond de-emphasis.

AUTOMATIC MUTE LEVEL: Variable from O to -3O dBm.

MUTE DELAY: Adjustable 0.5 to 20 seconds.

INJECTION LEVEL: 1% to 30% of composite level (adjustable).