C12 HA Console Speech Input AssemblyDescription: Built by Canadian Marconi under licence from Collins Radio.
(Audio Mixing Panel)
Type: C-12 HA 78247A
End Use: Broadcasting industry.
Basic features: 7 separate amplifiers, 14 tubes and 16 transformers.
Inputs: Up to four microphones
Up to two turntables
Up to six incoming lines.
Outputs: All module outputs used a 600 ohm termination.
Tube lineup: 7 x 6J7, 2 x 6C5, 2 x 2A3, 2 x 41, 1 x 5Z3
DImensions: Width - 35 in.
Height - 11 in.
Depth:- 15.5 in.
Power input: 110 VAC 50/60 Hz 1.7 amps 100 watts
|C12HA front panel. The meter opening was widened by hand to reduce the effect of the front panel steel on the meter movement. This modification was likely done by a previous owner.|
|Right side view. The Hammond transformer was not likely part of the original design. It was probably added boy one of the mixer's previous owners.|
|Self test meter detail.|
|Left side view. It is normally covered by a lid.|
|Chassis top view|
|Chassis bottom view|
|THis view illustrates the outboard power supply used with the C12.|
|Download any image to enlarge. All photos in this table by J Douglas Hensley|
|Technical specifications for the C12HA can be found in this brochure. Click on the image to launch the PDF file. (Courtesy Collins Radio)|
|This marketing brochure from Collins Radio describes other variants in the Model 12 Speech Input family. Click on image to enlarge. (Courtesy Collins Radio)|
THE C-12HA IN SERVICE
|Here is the C12HA audio mixer in its native habitat. Taken in 1937, this was the control room for AM radio CKUA in Edmonton, Alberta. (Photo courtesy CKUA radio archives)|
|A C-12 at KPQ in Washington state. A young Mark Sorley is at the helm. (Photo courtesy of the Jerry Lee Lewis photo archive section of the Library of American Broadcasters)|
|The NBC affiliate WMBG during their 1380 Show. (Photo courtesy of the Jerry Lee Lewis photo archive section of the Library of American Broadcasters)|
Contributors and Credits:
1) J Douglas Hensley, W5JV, <doug.hensley(at)gmail.com>