Original 1943 electrical trade vintage ad for HEWLETT-PACKARD COMPANY.  Main office and plant was located in Palo Alto, CA.

Manufacturers of Electronic Test Equipment.

Products include: Model 500A Electronic Frequency Meter. - A direct reading Electronic Frequency Meter to read the frequencies in the range between 10cps and 50kc. At the higher frequencies you can measure the frequency difference between two radio frequency signals. 

Has product image,  description, applications and specifications provide extensive product details.

Unbound from a 1943 electrical engineering magazine, this unique old one-page advertisement would display beautifully matted and framed. Nice graphics. World War 2 propaganda. A fabulous addition to your retro electrical library.