1977. Two Heathkit Manuals. Bindings slightly loose in places. Pages show some small markings. Covers, corners and page edges have moderate shelf wear and aging. Good condition. File in oversize.

~ Heathkit Manual For The 110 NHz Frequency / Period Meter Model IM-4110 (595-1919-02), Paperback, Heath Company, 1977. Pages show some small markings. Cover shows scuffing and wear with mild staining. Includes fold out schematic.

~ Heathkit Manual For The Sine-Square Audio Generator Model IG-5218 (595-1975-01), Staple Bound, Heath Company, 1977. Pages show some small markings. Cover shows scuffing and wear with mild soiling. Former owner's name on front.