Manual-Sinadder-S-101操作说明书手册

HclpeR/5-1olGeneral Doscriptionalnadder5.General DescriptionThe SINADDER'is a specialized distortion meter for making SINADmeasurements on radio receivers.Special circuit dosign speeds andsimplties the SINAD measurement by eliminating all distortion moterad小ustments。The null circuits of the SINADDER are internally set to the 1,000 Hz toneused in SINAD measurements,and an automatic gain control eliminatesthe need for setting input gain to the meter.The automatic gain control teature permits the SINADDER to be used as arecaiver alignment tool,providing rapld alignment of recelvers for optimumperlormance.Circuit DescriptionA block diagram of the SINADDER is piven in Figure 1.The input clrouits ofthe SINADDER are connected to the audio cutput circu'ts of the rocelverbeing tested.The signal appearing at the input to the SINADDER consistsof the wanted 1,000 cycle "Signal"frequency and other frequencies repre-senting the nolse and distonion creatod in the receiver.This compositeSignal,Noise.and Distortion signal is amplfied by two cascaded AGC