Signal Switcher and Video Distribution Amplifier

The video/audio switcher in BAVC's remastering center is a simple routing device with six buttons on the front. On the back of the switcher is a bank of connectors corresponding to each button, with one video and two audio inputs. Each of the tape machines' video and audio outputs are connected to one of the input banks, and the selected buttons sends the inputs to the one output of the switcher.

The purpose of a video switcher is to give the technician an efficient means Of switching among a number of devices; at BAVC we use the switcher to select among a number of playback decks. Without a switcher the technician would need to re-cable each deck every time the configuration changed. Initially when a 1/2" open reel tape is played back, the technician does not know whether it is "skip field" or EIAJ. Also, tapes play slightly differently on the two different EIAJ tape machines. As the tape is mounted on a tape machine, the tech need only select the switcher button corresponding to that machine to send the video signal to the TBCs and the monitor. When it comes time to do the transfer, the audio is patched to the audio input of the recording machine.

A video distribution amplifier multiplies the output of the switcher. This VDA takes one input (the switcher's output) and amplifies it and sends it to six outputs. These outputs are connected to the two TBCs and to the B Input of the monitor. One output on the VDA is unused. Now the signal of each tape machine can be viewed as it passes through the BVT-810, through the DPS TBC IV, and as it goes directly to the monitor. The technician has the opportunity to choose the best process for the video signal before doing the transfer.

BAVC's video/audio switcher and video distribution amplifier are made by Sigma. The two devices can be mounted in a Sigma rackmount tray, and they both take up only one rack space.