For all of you with the 859X series portable spectrum analyzers, here is some information that may be useful. Earlier versions of the analyzers used a power supply which was designed and made outside of HP. After a few years, failures started surfacing and HP (re)designed the supply in-house. The later supplies are therefore a HP design and those are the ones for which a schematic is often available. Those schematics will have the HP logo, etc. in the bottom right corner.
Vladan
