THIS PRODUCT IS NO LONGER IN PRODUCTION
The DAVID II combines simple-yet-effective and comprehensive audio processing with a digital-synthesis stereo generator. The result is an FM airchain of surprising performance and exceptional value. Audio processing functions employ quasi-digital pulse-width-modulation (PWM) techniques for stable, adjustment-free operation.
DAVID II also has built-in combining for SCA or RDS/RBDS subcarriers. plus an adjustable composite clipper.
55dB, 50Hz-15kHz (typically 60-70dB)
Better than 75dB below 100% modulation in baseband and subcarrier. Any “digital” noise components above 54kHz are –70dB or better.
<0.5%THD in baseband and subcarrier at 95% modulation with processing engaged.
Nonlinear crosstalk is better than –50dB, 50Hz-15kHz. Linear crosstalk (through processing and filters) is better than –40dB.
19kHz, ±1Hz; adjustable between 6% and 12% relative to 100% modulation.
Active-balanced, bridging; accept program audio levels between –15dBu and +15dBu.
Unbalanced input for SCA or RDS subcarriers at levels between –20dBu and 0dBu for nominal 5-10% injection.
7-pole, phase-corrected, active-elliptic LPF with proprietary overshoot compensation.
75µs or 50µs with jumper selection.
±10dB capture range with slow (0.5dB/sec.) correction for long-term input level variations.
Fast peak limiter with secondary “platform” for dynamic range compression. Independent high frequency limiter protects the pre-emphasis characteristic.
0dB to 3dB adjustable clipping of the baseband prior to pilot and subcarrier insertion.
75-ohm, unbalanced; variable between 1V p-p and 8V p-p, corresponding to 100% modulation.
608kHz (16X subcarrier oversampling)
105-130VAC or 210-255VAC, 50/60Hz; 15W
1- 3/4” H x 19” W x 7” D (1U); 7 lbs.