Instruction Manual, DVM-2000
SPECIFICATIONS
8
DVM-2000-FRX RECEIVER SECTION
The data modulated light beam is transformed into a balanced PECL bit stream and
presented to U15, a monolithic high-speed deserializer. The internal state machine of U1 driven
asynchronously by Y1 a monolithic crystal oscillator, recombines the data into a 16 bit parallel bit
stream. Internal phase lock loops regenerate the sending end sampling clock with an edge
stability of a few pico-seconds. The first 12 bits of the reconstituted data are presented to U16,
the video analogue to digital converter that reconstitutes the original video signal. R16, a front
panel control varies the converter’s DC reference thus adjusting the output gain. LPF1 is the
reconstitution low pass filter that removes the clock components from the video. U17 provides
gain and flatness adjustments while interfacing the video to the outside world. The audio portion
transforms the three audio bit stream again into audio. The associated operational amplifiers are
2 pole low pass filters and output drivers. U1 edge detects the audio channel pulse and triggers
monostable multivibrator U3 that produces a strobe pulse occurring at the center of the digital
audio’s user bit location. The positive edge of U3’s output strobes that location recovering
external data and remote video presence indication. The whole audio system calibration relies
just on 6, one per channel, output gains.
SPECIFICATIONS
Video Performance:
Exceeds the RS-250C Short-haul specification.
Signal to noise ........................................................................................... > 75 dB
Differential gain ......................................................................................... < +/- 0.3 %
Differential phase ...................................................................................... < +/- 0.3
°
Chrominance to luminance gain ................................................................ < +/- 1 %
Chrominance to luminance delay .............................................................. < +/- 10 nsec.
Frequency response to 8 MHz................................................................... < +/- 0.1 dB
3 dB Bandwidth ......................................................................................... 8 MHz
Luminance non-linearity............................................................................. < 1 %
Ringing ...................................................................................................... < +/- 0.5 %
Tilt.............................................................................................................. < +/- 0.2 %
Video output & input impedance................................................................ 75 Ohms
Audio Performance:
Signal to noise ........................................................................................... > 90 dB
Frequency response to
20 Hz to 20 KHz
................................................... < +/- 0.1 dB
Distortion ................................................................................................... < 0.05 %
Audio output level, adjustable.................................................................... Unity, +/- 6 dBm
Maximum input & output level, 600 Ohm termination ................................ +18 dBm
Audio output impedance, balanced ........................................................... 50 Ohms
Audio input impedance, balanced (selectable) .......................................... 600 Ohms or High
Data channels
RS-232C, RS-422, CMOS
Power dissipation ...................................................................................... < 15 Watts, per unit
AC operation.............................................................................................. 110 or 220 VAC (optional
48VDC)
Operating temperature .............................................................................. 0 to +50
°
C
Portable and Wall-mount: .......................................................................... 7” L x 5 ¾” W x 1 ¾” H
Triple Rack-mount Kit for 3 modules (Part number -RMT): ........................ 7” L x 19” W x 1 ¾” H
Specifications subject to change without notice.
