4191AHP1MHz-1GHzTheAgilentHP4191AisareconditionedRFImpedanceAnalyzerthatmeasures14parameterswithamaximumresolutionof41/2-digits.Theinternalsynthesizerprovidesvariablefrequenciesfrom1MHzto1000MHzcoveringtheUHF,VHFandvideobandswithautomaticsweepcapability.