Hi Paul,
"The HP 70590A Options H69 and H72 TMAs (Test Module Adapters) are MATE modules for HP 70000 Series spectrum analyzers. The modules translate CIIL (control intermediate interface language) into the HP 70000 Series native code. Option H69 modules provide a calibration switch signal at the rear panel. Option H72 modules switch the RF and Calibrator signals to the analyzer's RF input."
See
I'm guessing you are wondering why a UK eBay seller thinks he might get up to ?1000 for one!
Regards,
Steve
