HP 400D VACUUM TUBE VOLTMETER SERIAL NUMBER 13193 AND UP OPERATION & SERVICE MANUAL. THIS IS AN ORIGINAL MANUAL.
I HAVE SO MANY MANUALS MY MANUALS HAVE MANUALS!!!! IF LOOKING FOR A SPECIFIC ONE E-ME AND I'LL SEE IF I HAVE IT. I HAVE 1000'S. I CAN NOT ADD A PIC OF EVERYONE OF THEM BUT THEY ARE ORIGINAL MANUALS.
