The DPCM Encoder accepts parallel PCM signals from the PCM Encoder and produces a parallel Differential Pulse Code Modulated (DPCM) signal. 

A DPCM signal results when consecutive PCM signals are subtracted, so that only the difference between the signals is transmitted. DPCM offers advantages over PCM for voice signals, such as lower sampling rates and the ability to multiplex more channels on the same transmission link. DPCM requires fewer bits to encode the analog information and suffers less from noise degradation than PCM.

Using the DPCM Encoder, students gain an understanding of the processes used to obtain DPCM signals, the differences between PCM and DPCM, and the advantages and disadvantages of each.

Specifications

Power Requirements: Connection to the Enclosure / Supply Regulator, Model 9420 (not included)
Inputs: 8-bit parallel PCM end of conversion (from PCM Encoder)
Outputs: Less than 8-bit parallel DPCM

Input/Output
Voltages: TTL
Fault-Insertion Switches: 8
Test Busses: 6

Physical Characteristics
Dimensions (H x W x D) 83 x 142 x 212 mm (3.3 x 5.6 x 8.3 in)
Net Weight 0.9 kg (2.0 lb)