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The 706 is Inovonics' second-generation FM Stereo Generator which includes the FMX "Coverage Extension" Transmission System as an easily-installed plug-in option.

The 706 Generator incorporates the necessary preemphasis and low-pass filtering functions required in customary broadcasting practice, and features patented compensation cicuitry to avoid modulation sacrifices due to overshoots in the primary low-pass filter.

FM subcarrier(s) and Pilot are digitally synthesized for optimum and adjustment-free operation.


  • Digital Synthesis of composite signal that assures optimum performance and drift-free, adjustment-free operation.

  • Patented filter overshoot compensation

  • Accurate metering of important internal signal levels

  • Internal combining circuitry for up to three SCA or RDS channels.

  • Separate 19kHz TTL Output

  • Built-in Composite Processor

  • Remote control of input selection

  • Fully compatable with all Inovonics and most other audio processing systems



Frequency Response

±0.25dB, 25Hz-16kHz; -25 or better at 10Hz, -60 or better at 19kHz.

Stereo Separation

70dB, 25Hz-10kHz;

<60dB, 10kHz-16kHz (L/R, or R/L)


Main-to-Sub, -70dB or better;

Sub-to-Main, -65dB or better.


<0.05% THD in demodulated audio 1dB or more below 100% modulation; Mono or Stereo mode, 22Hz-16kHz


Better than 85dB below 100% modulation in demodulated audio, Mono or Stereo; “spectral” noise components in composite output better than 75dB below 100% modulation, 25Hz-1MHz.


50µs or 75µs, user-selectable; ±0.5dB over curve.

Stereo Pilot

19kHz, ±1Hz; injection level adjustable between 6% and 12% relative to 100% modulation. Pilot distortion <0.5% THD.

Program Inputs

“Main” Left and Right program inputs are active-balanced, bridging; accept line input levels between -10 and +15dBu. (OdBu=0.775V r.m.s.) Alternate, single-ended inputs bypass preemphasis and input conditioning circuits.

Input Filtering

7-pole, phase-corrected, active-elliptic “FDNR” low-pass; third-order Chebyshev high pass.

Overmodulation Protection

Integral part of input filter overshoot control circuit; defeatable with same.

SCA/RDS Inputs

Single-ended; accept input levels between -5 and +10dBu for 10% modulation.

Composite Outputs

Two independent single-ended “zero impedance” outputs; adjustable between -5 and -12dBu (0.5 to 3 V r.m.s. or 1.2 to 8V p-p).

Pilot Output

TTL-level symmetrical squarewave in phase with 19kHz Stereo Pilot.

Remote Control

Requires momentary contact closures to ground to switch FMX™ System ON or OFF, or to switch to MONO operation from Left or Right or L=R, or to return to STEREO mode. Generator defaults or “wakes up” to STEREO mode with FMX™ System ON.

Digital Synthesis Sampling Rate

608kHz (16X subcarrier oversampling).

Power Requirement

105-130VAC or 210-255 VAC, 50/60Hz; 8 Watts.

Size and Weight

3-1/2”H x 19”W x 10”D (2U); 10 lbs.