FREQUENCY SYNTHESIZERS GENERATING RADIO FREQUENCIES

Brand	Owner	Address	Description
P T S	Programmed Test Sources, Inc.	9 Beaver Brook Road Post Office Box 517 Littleton MA 01460	frequency synthesizers generating radio frequencies covering the approximate frequency spectrum from 100 KHz to 20 GHz, for use in the integrated circuit automatic test systems, physical science experimentation nuclear magnetic resonance and imaging systems (NMR/MRI), electronic component manufacturing, testing and verification systems (e.g., crystal processing, radio frequency filter tuning) and general communications systems (e.g. satellite communications systems, TV/AM/FM/short-wave radio communications systems, commercial and military type radar communications systems);
	Where the owner name is not linked, that owner no longer owns the brand

Technical Examples

A method and apparatus provide for monitoring radio frequency signals and, in conjunction with the monitoring, determining frequency of a received dominant radio frequency signal. Zero amplitude transitions of the signal are counted in primary and secondary sampling periods to determine frequency and frequency stability. The method and apparatus can be used to tune to radio frequency signals having frequencies in a list of frequencies to be monitored and detecting signals in the radio frequency spectrum on other frequencies. The monitoring and scanning may occur simultaneously, sequentially, or in any order or sequence. The frequencies of dominant signals received are determined and added to the list for monitoring. The receiver may be tuned to a frequency determined immediately upon determination of the frequency determined, after storage of the frequency determined, only after a signal on the currently monitored frequency terminates, or upon other conditions. A user of the apparatus can build a list of frequencies to be monitored automatically without sophisticated knowledge or equipment.