A New Approach to an Audio Console for Television

An audio system has been designed that is strongly resistant to the effects of noise and hum from nearby video monitors, power transformers, SCR light dimmers, etc. The new audio system is based ultimately on just three different components: the Raytheon CK-1115 Light Dependent Resistor or LDR, the Beyer type BV35570 miniature audio transformer and the RCA type CA3036 integrated circuit. When these components are assembled in a few basic combinations on Vector type 812WE pegboard cards (used for the security of gold-to-gold contact and the simplicity of replacement), high-quality building block modules, such as the 20-dB audio amplifier, are obtained. From such modules are constructed a microphone preamplifier, a fader card, a bridge card, a mixer card and a booster card along with a line amplifier and a monitor driver card. The immunity of the system to hum and noise is shown by the fact that the system shows a 63-dB SNR with a — 60-dBm input level to a microphone preamplifier when 26 nearby video monitors and three racks with power transformers are operating — and the SNR improves by only 0.25 dB with all this equipment turned off. Reliability also has been nearly perfect.

Print ISSN

0361-4573

Published

1973-11

Content type

Original Research

DOI

10.5594/J07664