Anritsu Scorpion MS4623B Vector Network Analyzer This is an excellent instrument with dynamic range of 125 dB. Note that even the latest ES units of Agilent's 8753 series don't go over 110 dB... The later Agilent E units are obviously better, but they are in totally different price range... Here is a short list of useful Anritsu Scorpion resources: Measurement Guide Operation Manual Programming Manual Specification Guide Maintenance Manual Intermodulation Distortion (IMD) Option 13 Application Note Dead Scorpion Recovery Procedure Wiltron 26N50 and Others - Specification