ELECTRONIC A RELAYS FOR USE IN TELEPHONE SWITCHING DEVICES, REMOTE LINE DISCONNECT UNITS FOR USE IN TESTING TELEPHONE TRANSMISSION LINES AND ELECTRONIC DEVICES FOR MEASURING CRITICAL TELEPHONE LINE PARAMETERS SUCH AS RESISTANCE, CAPACITY, HAZARD VOLTAGE AND VARIOUS GROUND MEASUREMENTS

Passive geophysical exploration devices for the oil and gas industry, namely electronic systems for measuring geophysical electromagnetic radiation comprised primarily of a computer, antenna and spectrum analyzer