Note
Ham Radio, Nov 1976, p. 120
Ham Radio, Feb 1977, 116.
Ham Radio, Jul 1977, p. 106. (Model 700)
The synthesizer may be plugged into the headphone or speaker jack of a receiver or other monaural audio signal source and provides stereo outputs for headphones, power amplifiers, or speakers.
The model 400 Binaural Synthesizer is available as a complete unit as a partially assembled unit including an assembled and tested PC board or as a kit which includes a pre-drilled, plated, glass-epoxy PC board.
The model 400 provides a sharp 24 dB per octave channel separation, four poles in each channel, for a good stereo effect. The unit employs 741 integrated-circuit op amps rather than multiple units for simple, easy-to-find attachment points.
The PC board contains extra traces for resistor trimming, if desired. The cross-over frequency is 750 ±50 hertz, input impedance is 2000 ohms, and the unit may be powered from any supply that will provide negative or positive voltage between 4 and 15 volts DC. In operation, the synthesizer typically draws 5 to 10 mA.
The model 700, introduced in July 1977, worked the same but included the Tone-Tag function first made available in the model 1100.
