Electrical noise detector for detecting power line gap defects

Apparatus for detecting a defect in power line equipment in response to broadband radio frequency electrical noise generated by such defect, comprising:

• antenna for receiving radio frequency noise;
• radio receiving means coupled to said antenna for producing first electrical signals of varying amplitudes representative of the received radio frequency noise;
• means for generating second signals corresponding to time periods when the amplitude of the first signals are greater than a first predetermined level, said means for generating the second signals including a squelch circuit having first and second inputs, and a reference voltage, with the first signals being coupled to the first input and the reference voltage being coupled to the second input, said squelch circuit generating the second signals in response to the first signals, with the second signals corresponding to time periods when the first signals are greater than the reference voltage;
• means for sampling said second signals and holding the levels of each of said second signals to their respective input values for a predetemined sampling time such that a third set of signals is produced thereby, said third set of signals being separate collections of groups of said second signals such that said third set of signals are essentially digitized, representations of said groups of second signals;
• means for determining when said third set of signals have a predetermined periodic bandwidth associated with gap noise and for providing a fourth set signals in response to the recurrence of said third set of signals which have frequencies within said periodic bandwidth;
• and, indicator means response to said fourth set of signals.