> I use HP859x series of spectrum analyzers, particularly 8591EM if
>> available.... I'm quite fond of these
>> old HP SAs.
Don't they have "instrument BASIC" built-in? I.e., you can write all sorts of data processing programs write on the instrument itself if you don't have a PC handy? Granted, these days that's unlikely, but in many ways it seems that those older instruments had more features than some of the new models!