EDM (Geodimeter Model 6)
"AGA Geodimeter Lidingo Sweden Model 6 No. 6194"
21 inches high, 14 inches wide, 8.5 inches deep
The Geodimeter Model 6, introduced in 1964, was a transistorized instrument with coaxially mounted transmitter and receiving optics. It had a range of 1-2 miles in daylight, and 10 miles in darkness, and a standard accuracy of 5 mm + 1mm/km. Without case or tripod, it weighed a mere 35 pounds. Advertisements showed it being carried by a woman, with text stating "Your assistant can look like this." Equipped with a tungsten lamp and various accessories, it cost approximately $10,000 and could be powered with a 12-volt car battery. A
mercury vapor lamp for the Model 6 cost some $2,500 more, and required a special generator. Michael Baker Jr., Inc., purchased this instrument in 1966, and donated it to the Smithsonian Institution in 1997.
Ref: AGA, Geodimeter Model 6A Operating Manual.