Zoomar Television Lens, by Dr. Frank Back, serial number 40.

The Zoomar Television lens was designed by Dr. Frank G. Back (also spelled Bach) in the late 1940s for use with RCA black and white television cameras.  This particular lens was part of an RCA TK-11 camera package.  The lens is in fair condition, suitable for display or restoration.  There is lens fog on some of the internal elements. 

The Focus, Zoom and Iris adjustments all operate though they are a bit tight from age.

The package consists of the following:

• Zoomar Television lens serial number 40
• Tele-Front Lens (5~22 inch) serial number 40
• Fiber case
• Miscellaneous mounting attachments and adaptors (4)

Specs:

• Overall length 32”
• f 5.6 to 22
• Net Wt: 20 pounds

Features:

• C-mount 
• removable front element
• Combination Rod operated twist focus and Push Zoom.

More information regarding Dr. Back and a variety of lenses can be found here:   https://www.zoomlenshistory.org.uk/who-invented-the-zoom-lens/frank-g-back-zoomar/