A single self-contained instrumentation package, Model 191 meets the basic needs of audio testing in production, QC, education and service applications. It helps to minimize bench clutter particularly in those applications where audio is only part of the system makeup. The 191 combines the functions of test signal source, precision attenuator and output measuring AC millivoltmeter.
GENERATOR
Offering both sine and squarewave operation the generator covers frequencies of 10 Hz to 1 MHz in 5 ranges. Sinewave output is 3 V rms max into 600 W. Output connectors are both banana terminal posts and a pair of phono type jacks. Provision is made to switch in a 600 W shunt to form a 600 W source resistance.
AC MILLIVOLTMETER
A pair of independent AC millivoltmeters share a common set of meter scales. The scales are calibrated in rms volts, dBV and dBm. Twelve ranges cover full scale readings of 0.15 mV to 500 V, -80 dBm to +56 dBm. Bandwidth remains flat (within 2%) from 20 Hz to 100 kHz. A unique mechanical link allows both range switches to lock together. However, the center knob can be disengaged for independent operation and re-engaged at a selected offset. Accuracy is ± 2% of full scale at 1 kHz. Output connectors allow the internal amplifiers to be used as high gain preamps to drive oscilloscopes or for other purposes.
ATTENUATOR
Total attenuation range is 0 -120 dB in 1 dB steps at 600 W.
