In combing through the pile of info from the HP Dayton sales office , I am running across a number of "SERVICE NOTES" . I will be uploading these to Didier's (KO4BB) site for general distribution as I  have time to scan them ( which won't be often  8^)

To that end I ran across this interesting tidbit.

Seems that the 8501A Storage Normalizer can be used with either the 8505A or the 8754A network analyzers. The catch is that the 8501A must be setup for use with the particular network analyzer in question. This includes cover off settings inside the 8501A . There was supposed to be a sticker added to the 8501A noting that it has been reset to the 8754A compatibility mode. Once set for 8754A the 8501A can not be used (with out resetting) with a 8505A and vice versa. While the note describes converting a 8501A / 8505A combo to a 8501A / 8754A combo, I would assume that you if have an 8501A which was previously set for the 8754A that you could reverse the sequence and reset it for the 8505A. In this day and age where these items have traded homes many times it is hard to know what the history of a unit is 8^)

The service note 8501A-4 has been uploaded to KO4BB's site and I assume it will be added to regular files area in the next day or so

Dave