Specifications

PERFORMANCE
SPEECH MODE

Frequency response: Follows standard 150us preemphasis curve ±0.5dB, 50-3,000Hz. Strappable 6dB/octave bass-cut filter provides greatest intelligibility and modulation efficiency.
Noise (150us deemphasis): <-60dB referenced to 100% modulation.
Total system distortion (PROOF MODE, 150us deemphasis): <0.5% THD, 50-3,000Hz.

DATA MODE

Frequency response: ±0.1dB, 5-3,200Hz.
Group delay: Constant ±2% or better, 5-3,200Hz.
Total system distortion (no deemphasis): <0.5% THD, 50-3,000Hz.

INSTALLATION
LOCATION

8185A/PRO is contained on two cards that mount into slots in the 8185A Stereo Generator.

INPUT

Impedance: >10k ohm load impedance, electronically, balanced by means of true instrumentation amplifier. Requires balanced source £600 ohms. Common mode rejection 54dB @ 60Hz.
Sensitivity: -30dBm to +10dBm to produce 10dB gain reduction @ 1kHz (SPEECH mode), or 100% modulation (DATA mode).
Connector: Barrier strip (#5 srew), EMI suppressed.

CIRCUITRY SPEECH PROCESSING

Phase scrambler: Allpass network makes asymmetrical voice waveforms more symmetrical.
Compressor: Fast-attack variable gain circuit; compression ratio nearly infinite. Uses delayed release-time to minimize distortion on low frequency signals. Two LEDs on the subpanel indicate NORMAL and HEAVY gain reduction.
Peak clipper and overshoot compensator: Peak clipper limits the signal to 100% modulation. Uses patented Orban Overshoot Compensator to avoid overmodulation after the subsequent 3.4Hz lowpass filter. (US Patent No. 4,103,243).

PHASE-CORRECTED LOWPASS FILTER

Type: Seventh-order elliptical filter, with sixth-order phase correction. Cutoff frequency of 3.4kHz complies with BTSC system specification.
Stopband rejection: >55dB above 4.5kHz.

PRO GENERATOR

Residual FM noise: -60dB referenced to 100% modulation (with 150us deemphasis); -50dB (no deempasis).

WARRANTY

One year, parts and labor. Subject to limitations stated in our Standard Warranty.

Specifications subject to change without notice.