Harris HT 25CD, 25 KW FM Transmitter

General

Power Output: HT 20CD: 8 to 21kW

HT 25CD: 8 to 26kW

Excitation: Harris DIGIT® CD Digital FM Exciter (included).

Modulation Type: Direct Digital Synthesis using a 32-bit NCO (numerically controlled oscillator).

Frequency Range: 87.5 to 108MHz, digitally programmable in 50Hz increments. Tuned to single frequency.

Frequency Stability: ±150Hz, 0°C to 50°C ambient temperature range (using internal frequency reference).

External Frequency Control: Capable of locking to an external 10MHz reference for use in FM synchronous applications when fitted with optional DIGIT CD Sync Board (992-9850-001). Sync input requirement: 2.82Vp-p or TTL level. Sync input connector: BNC female.

Load Impedance: 50 ohms, coaxial.

Output Connector: 3-1/8” EIA flange (female).

Maximum Load VSWR: 1.7:1 for 100% power, automatically reduces power to maximum safe level into high VSWR (proportional VSWR foldback).

RF Harmonics/Spurious Emissions: Meet or exceed FCC/IC/CCIR requirements.

Asynchronous AM S/N Ratio: 55dB minimum below equivalent 100% amplitude modulation by 400Hz using 75μs de-emphasis (no FM modulation present).

Synchronous AM S/N Ratio: 52dB minimum below equivalent 100% amplitude modulation with

75μs de-emphasis and 400Hz highpass filter (FM deviation ±75kHz by a 1kHz sinewave).

AC Input Power: 197 to 250VAC, 50 or 60Hz, 3 phase, 3 wire closed delta or WYE; or 360 to 415VAC, 50 or 60Hz, 3 phase, 4 wire WYE.

Power Consumption: HT 20CD: 30.8kW (0.95PF) HT 25CD: 37.5kW (0.95PF)

Ambient Temperature Range: -20 to 50 degrees C at sea level, upper limit derated 2 degrees

 C per 1,000 feet (304.9m) altitude.

Maximum Altitude: 10,000 feet (3,049m).

Humidity: To 95%, non-condensing.

Cabinet Size: Main Cabinet: 33.3” (84.6cm) wide, 30.2” (76.7cm)

deep, 72” (182.9cm) high; Power Supply: 48” (122 cm) wide,

24.1” (61cm) deep, 60” (152cm) high.

Weight: HT 20CD: 2,550 lbs. (1,159kg)

HT 25CD: 2,700 lbs. (1,227kg)

Stereo Performance with Digital Input Module

Input Data Format: AES3-1992 (reference standards: AES5-1984, ANSI S4.28-1984, AES3-1985, ANSI S4.40-1992, and AES3-1992).

Sample Rate: Any in range 32kHz to 56kHz (32, 44.1 or 48kHz typically output from AES3 devices).

Digital Stereo Generator: Complete digital composite stereo waveform generated in the digital domain from incoming AES3 stereo audio data, using a digital signal processor (DSP).

Digital Baseband Composite Limiting: Exclusive DSP “lookahead” techniques for control of peaks before overmodulation can occur. Active with on-board DSP stereo generator in stereo or monaural mode; pilot carrier and SCA signals unaffected. Limiter on/off and limit setting adjustable

from 0-18dB either locally or by standard remote control systems.

Pre-emphasis: 0, 25, 50 or 75μs, locally selectable.

Stereo Separation (sinewave): 60dB or greater, 10Hz to 15kHz.

Dynamic Stereo Separation (complex waveform): 55dB or greater, 10Hz to 15kHz.

Amplitude Response (L or R): 10Hz to 15kHz ±0.2dB referenced to selected pre-emphasis curve.

FM Signal To Noise Ratio (L or R): 83dB below 100% modulation at 400Hz; measured in a DC to 22kHz bandwidth with 75μs de-emphasis and DIN “A” weighting. Does not exhibit the subsonic noise associated with analog exciters.

Stereo Total Harmonic Distortion: 0.009% or less at 5kHz, 0.015% or less for any modulating frequency from 10Hz to 15kHz; measured in DC to 22kHz bandwidth with 75μs deemphasis.

Intermodulation Distortion (L or R): CCIF: 0.025% (14/15kHz 1:1), SMPTE: 0.025% (60 and 7000Hz 1:1).

Transient Intermodulation Distortion (DIM) (L or R): 0.005% (2.96kHz square wave/14kHz sinewave modulation).

Linear Crosstalk: L+R to L-R and L-R to L+R due to amplitude and phase matching of L&R channels (DC-15kHz): 76dB below 100% modulation reference.

Non-Linear Crosstalk: L+R to L-R and L-R to L+R due to distortion products: 80dB below 100% modulation reference at 400Hz.

RBDS/RDS Synchronizing Signal: 19kHz quasi-sinewave, nominal 5.6Vp-p, AC coupled, 100 ohm output impedance (unbalanced); for use by customer-supplied, external generator.

BNC female connector.

Stereo/Monaural Mode Control: Selectable locally or by standard remote control systems. Zero amplitude pilot in monaural mode

Emergency Analog Composite Mode: Switchable locally or by standard remote control systems to mute the on-board DSP stereo generator and accept analog composite stereo on SCA

Port #2. Nominal input sensitivity (all SCA ports in this mode): 3.5Vp-p (1.24V RMS) for ±75kHz deviation. FM signal to noise ratio: 85dB below 100% modulation. Total composite harmonic

distortion: 0.02%.

Composite Input Performance With Analog Input

Module

Inputs: Two: XLR female balanced (switchable, composite or monaural), and BNC female unbalanced.

Input Impedance: Balanced/unbalanced: 10,000 ohms nominal, resistive.

Input Level: 3.5Vp-p (1.24V RMS) nominal for ±75kHz deviation.

FM Signal To Noise Ratio: 93dB below ±75kHz deviation at

400Hz; measured in a DC to 100kHz bandwidth with 75μs deemphasis; DIN “A” weighting. Does not exhibit the subsonic noise associated with analog exciters.

Amplitude Response: ±0.02dB, DC to 53kHz; ±0.25dB, 53kHz to 100kHz.

Total Harmonic Distortion: 0.01% over stereo sub band (10Hz to 53kHz) referenced to ±75kHz deviation.

Intermodulation Distortion: CCIF: 0.008% (14/15kHz 1:1); SMPTE: 0.008% (60/7000Hz 1:1).

Transient Intermodulation Distortion (DIM): 0.005% (2.96kHz square wave/14kHz sine wave modulation).Slew Rate: 9V/μs, symmetrical.

Group Delay Variation: ±10ns, DC to 53kHz, ±50ns, 53kHz to 100kHz.

Phase Response Variation: ±0.15° from linear phase, DC to 53kHz.

Stereo Performance with Analog Input Module

NOTE: Analog stereo performance is defined mainly by the

external stereo generator and program path. The following

specifications are typical when using high quality source

equipment.

FM Signal To Noise Ratio (L or R): 77dB below 100%

modulation at 400Hz; measured in a DC to 100kHz bandwidth

with 75μs de-emphasis (A-weighting). Does not exhibit the

subsonic noise associated with analog exciters.

Amplitude Response (L or R): 10Hz to 15kHz ±0.5dB referenced

to selected pre-emphasis curve.

Total Harmonic Distortion (L or R): 0.015% from 10Hz to

15kHz; measured in a DC to 22kHz bandwidth with 75μs deemphasis.

Intermodulation Distortion (L or R): CCIF: 0.025%; SMPTE (60

and 7000Hz, 4:1): 0.025%.

Transient Intermodulation Distortion (DIM) (L or R): 0.005%

(2.96kHz square wave/14kHz sinewave).

Stereo Separation (sinewave): Better than 60dB, 10Hz to 15kHz.

Non-Linear Crosstalk: L+R to L-R and L-R to L+R due to distortion

products: 80dB below 100% modulation reference at 400Hz.

SCA (RBDS/RDS) Performance with Digital or Analog

Input Module

NOTE: Analog SCA/RBDS/RDS performance is defined mainly by

the external subcarrier generator and program path. The

following specifications are typical when using high quality

source equipment.

Inputs: 3 total, BNC female connectors.

SCA Format: Externally generated, analog FM subcarriers in the

range 57-100kHz.

SCA Input Impedance: Analog Module: 10,000 ohms

unbalanced, nominal, resistive. Digital Module: 3,000 ohms

unbalanced, nominal, resistive.

SCA Input Level: 1.5Vp-p nominal for ±7.5kHz deviation of main

carrier.

SCA Subband Amplitude Response: ±0.25dB, 53kHz-100kHz.

SCA Channel Audio Response: Defined by response of SCA

generator and SCA program path.

SCA Channel FM Signal To Noise Ratio: 74dB below ±6kHz

subchannel deviation at 400Hz with 150μs de-emphasis.

SCA Audio Harmonic Distortion: 0.4% or less in audio passband

of SCA generator.

SCA Audio Intermodulation Distortion: SMPTE (60 and

7000Hz, 1:1): 0.4% or less, no pre-de-emphasis, SCA

generator lowpass filter bypassed.

Crosstalk, SCA to Stereo: 65dB below 100% modulation, L or R

channel with 75μs de-emphasis.

Crosstalk, Stereo to SCA: 55dB below 100% modulation

(referenced to ±6kHz deviation and 150μs de-emphasis in SCA

demodulator).

Crosstalk, SCA to SCA: 55dB below 100% modulation (referenced

to ±6kHz deviation and 150μs de-emphasis per channel.

Monaural Performance with Analog Input Module

Input: One, XLR female (switchable: composite balanced or

monaural).

Audio Input Impedance: 600 ohms, balanced, floating, resistive;

adaptable to other impedances. 60dB common mode

suppression.

Audio Input Level: +10dBm nominal for ±75kHz deviation at

400Hz; locally adjustable from -9 to +14 dBm.

Amplitude Response: 10Hz to 15kHz ±0.2dB, referenced to

selected pre-emphasis curve.

FM Signal to Noise Ratio: 93dB below ±75kHz deviation at

400Hz; measured in a DC to 100kHz bandwidth with 75μs deemphasis

and DIN “A” weighting. Does not exhibit the

subsonic noise associated with analog exciters.

Pre-emphasis: 0, 25, 50 or 75μs, locally selectable.

Total Harmonic Distortion: 0.009% at 12.5kHz, 0.015% from

10Hz to 15kHz referenced to ±75kHz deviation, measured in a

DC to 22kHz bandwidth with 75μs de-emphasis.

Intermodulation Distortion: CCIF: 0.008% (14/15kHz 1:1);

SMPTE: 0.008% (60/7000Hz 1:1).

Transient Intermodulation Distortion (DIM): 0.005% (2.96kHz

square wave/14kHz sinewave).

NOTE: Analog SCA/RBDS/RDS performance is defined mainly by

the external subcarrier generator and program path. The

All specifications referenced to any single output frequency (87.5-

108MHz), 20/25kW output power, and 50 ohm test load.