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From AS 12-46-6756 until 6761 (EVA-1; The TV Camera)
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116:24:47 MT - Rightway of 6755. Close-up of the TV camera, with the Solar Wind Collector (SWC) at the left edge of the picture. Note the loop in the TV cable running off to the left.
Paul Coan, Manned Spaceflight Center Television Subsystem Manager who was responsible for the equipment used on the Apollo spacecraft, writes, "The same type of cable used to carry video and power between the Apollo 11 TV camera and the LM was used during Apollo 12 to power the first color TV camera to be put on the Lunar Surface.
However, the connector on the color camera did not match the connector on the end of the Lunar Surface cable that was an integral part of the camera handle. (See a detail from Apollo 11 photo S-69-31575 ). Since the design and qualification of the Lunar Surface cable was so expensive, it was cost prohibitive to replace the connector on the cable. Cost, schedule, and design constraints also precluded replacing the connector on the color camera.
So, we decided to build an adapter that provided the interconnection."
In a detail from 6756, the color-camera camera hangs down from the back, with the yellow-coated adapter immediately blow attached to the silver-tube of the 'handle' from the Apollo 11 configuration.
Coan adds, "During testing of the color Lunar Camera connected to the LM on the pad at KSC, we noticed hum bars in the video.
We then realized that the finite resistance of the power circuit in the 100 foot Lunar Camera cable combined with the switching power supply in the camera was sufficient to inject the hum bars in the video. We had to rework the power supply circuits to eliminate the hum bars. There was some quick redesign/rework done to make the camera work."
"Finally, there was a special room provided at KSC for final checkout of the cameras before they were installed in the spacecraft. So that we could test under controlled lighting conditions, the room was painted totally black and provided with heavy window curtains to eliminate light from outside".
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