Audio Signal Generator 206A

Frequency Range: The frequency coverage is from 20 cps to 20 kc in 3 ranges.

Calibration: The dial is calibrated directly in cycles for the lowest range, from 20 to 200 cps. Each range covers approximately 270 degrees of the 6” dial. The dial is located behind the panel and is illuminated. A six to one rim drive enables the equipment to be easily and quickly set to any desired frequency.

Stability: The frequency is calibrated to within better than 1% when the instrument leaves the factory. The circuit elements in  the frequency determining network have low temperature coefficients and good stability so that better than 2% accuracy will be maintained over long periods of time.

Output: The equipment will deliver an output level of + 15 dbm above 1 mw into impedance of 50, 150 and 600 ohms. Approximately 10 volts are available into an open circuit.

Output Impedances: The generator has a matched internal impedance and the selection of output impedances includes 50, 150 and 600 ohms center-tapped and balanced and 600 ohms single ended.

Frequency Response: The frequency response of the system beyond the output meter is better than 0.2 db at all levels, 30 cps to 15 kc.

Distortion: The total harmonic distortion in the output voltage is less than 0.1% at frequencies above 50 cps and less than 0.25% from 20 cps to 50 cps.

Hum level: The residual hum and noise in the output signal is at least 70 db below the output signal or more than 100 db below zero level, whichever is the larger.

Output Meter: The output voltage is measured ahead of the attenuators by a 4” square meter calibrated in dbm and also in volts. The meter has a scale which can be read to at least 0.2 db at all points above a 50% scale reading. (Zero dbm equals 1mw in 600 ohms.)

Output Attenuators: Output attenuators provide a range of 111 db in 0.1 db steps. The individual resistors in the attenuators are adjusted to better than 0.2% and the accuracy of the attenuators is approximately 0.1 db.