Portable Spark Gap Transmitter - Type 11982
Purpose: Portable spark gap transmitter used in WWI era aircraft.
Manufacturer: Marconi Wireless Company of Canada
Model : 11982 S/N 1
Power input: External battery.
Circa : Believed to be 1918 . The Marconi Wireless Company of Canada operated under that name between 1905 and 1925, After 1925, the company was renamed to Canadian Marconi.
|The black Bakelite scale at the 7 o'clock position has the following markings: 100, 125,150, 175, 200 and 250. These are believed to be in meters. Selecting a particular position on the coil determined the operating frequency.|
|The black object on the interior left side is a Rolled Condenser. It was made by the Northern Electric Company Ltd. and Patented in 1905. The capacity, in M.F., is illegible on the hi res photos but it's a Type 21(?) with an illegible variant.|
|This view shows the under panel wiring. At the right side is the vibrator adjustment for the internal spark coil.|
|All photos in this table by Tim J Patton, K4TJP.|
|In contrast, the SCR-65 (circa 1918), a quenched gap spark transmitter, was used in WWI era aircraft. It was manufactured for the United States Signal Corps and was also designated as the BC-15. (Photo courtesy radiomuseum.org)|
Contributors and Credits:
1) Tim J Patton K4TJP <tjpatton44(at)gmail.com>
2) SCR-65 photo http://www.radiomuseum.org/r/connecticu_airplane_radio_telegraph.html
3) Richard Dillman <ddillman(at)igc.org>
4) Will, W0EOM(at)aol.com