Abstract A self-testing equipment for a frequency-modulated receiver includes a pulse generator rich in harmonics and having a repetition frequency chosen such that the fundamental frequency is substantially equal to the channel spacing of the FM receiver being tested. The supply voltage for the pulse generator is derived from a power supply generator which produces a pulsating voltage varying periodically at a relatively slow rate. This voltage is applied to the pulse generator and serves to modulate the frequency of the pulse generator at the same rate. The accompanying harmonics of the pulse generator are also modulated but at a correspondingly high rate lying within the audio bandwidths of each receiver channel. Inserted between the power supply generator and the pulse generator is a time constant network which permits the supply voltage to vary exponentially during each power supply period. In this way, the frequency deviation of the pulse generator is controlled.
Inventors
👤 Vincent J De Fillipo
👤 Andrew R Saldutti
👤 Stanley J Zalesky
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-02 19:56
CPC Classifications
H; H03; H03B; H03B23/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
131 words
A method of testing a frequency-modulated receiver having a plurality of channels spaced in frequency by a predetermined amount comprising the steps of generating by means of a pulse generator a fundamental frequency substantially equal to said channel spacing and a plurality of harmonics of said fundamental frequency, deviating the frequency of the fundamental frequency of said pulse generator at a relatively slow rate and by a predetermined amount and the frequency of the harmonics of said fundamental at a correspondingly higher rate in response to a voltage which varies slowly in frequency and which varies in magnitude during each cycle of frequency variation; and coupling the deviated fundamental and harmonics to the input circuit of said receiver for testing the operability of the receiver channels to which said harmonics correspond.
Claim 2
Independent Claim
131 words
A method of testing a frequency-modulated receiver having a plurality of channels spaced in frequency by a predetermined amount comprising the steps of generating by means of a pulse generator a fundamental frequency substantially equal to said channel spacing and a plurality of harmonics of said fundamental frequency, deviating the frequency of the fundamental frequency of said pulse generator at a relatively slow rate and by a predetermined amount and the frequency of the harmonics of said fundamental at a correspondingly higher rate in response to a voltage which varies slowly in frequency and which varies in magnitude during each cycle of frequency variation; and coupling the deviated fundamental and harmonics to the input circuit of said receiver for testing the operability of the receiver channels to which said harmonics correspond.
Claim 3
Dependent Claim
39 words
A method of testing a frequency-modulated receiver according to claim 1 wherein said harmonics are spaced throughout the receiver spectrum at multiples of said receiver channel spacing whereby only one of said harmonics lies within any given receiver channel.
Claim 4
Dependent Claim
30 words
A method of testing a frequency-modulated receiver according to claim 1 wherein the deviation in frequency of said harmonics which lie within the receiver channels fall within the audio range.
Claim 5
Dependent Claim
26 words
A method of testing a frequency-modulated receiver according to claim 1 wherein the signal level of said coupled frequency-deviated harmonics are consistent with the receiver sensitivity.