Lifetime Carbon Microphone

This is a microphone of the double-button carbon variety. It requires a source of DC in series with the elements which are loaded with carbon granules that behave as a variable resistance when moved by the audio diapraghm. A double button mike normally uses a center-tapped input transformer with DC bias in series with the center tap.

Vintage is believed to be 1933 or a couple of years earlier. Spring-mounted carbon microphones were common throughout the 1920s into the early 1930s. Carbon mikes as used in the telephone predate radio. This mike is bright aluminum and still works fine. The words "Lifetime" and "Toledo" are engraved in the mike as well as the number "6". After a long search to try to identify the model or manufacturer, I found small ads in the August, October, and November 1933 issues of QST from the Lifetime Corporation, 1302 Dorr Street, Toledo, Ohio. The ads were for model "8". I assume that the model "6" is a somewhat earlier version. The specifications are very similar. The image on the right is from one of the ads.

David Letterman also has one of these
David Letterman has an identical Lifetime model 6 mike, given to him by the crew and staff of the LATE SHOW at CBS in honor of Dave's 10 years on that show.

Here is the link from CBS

Stands for spring mounted carbon mikes were typically sold sold separately. A 5 inch ring is appropriate for this mike. I made this simple replica ring stand to match the mike.