Sydney Video
Inverter Switch

Because of the relatively late decision by NASA to mount the Lunar Surface TV Camera upside-down in the MESA, it soon became apparent that some way of inverting the picture would be needed.

Inverter switches and associated circuirty were installed at Sydney Video (for the Parkes picture), Honeysuckle Creek and Goldstone.

Goddard Engineer Dick Holl, who was at Sydney Video for Apollo 11, designed the modification –


Sydney Video

Dick Holl relaxes in front of the Scan Converter after the EVA. The inverter switch, just to the left of the Alignment eyepiece, is arrowed.

Photo preserved by Dick Holl, scanned and enhanced by Bill Wood.

“That little dot above my head is the switch for inverting the video from the lunar camera upon deployment of the panel.

It is an off the shelf DPDT switch you can buy at any electrical outlet store.  

No one knows this better than me because I designed the TK-22’s ability to reverse its scan.

While I was at Goddard we discussed what to do about the video being upside down until the astronaut picked up the camera.

I had a TK-22 camera which I set up on a test bench and I added a small circuit board inside the camera with a couple of op amps and gates on it that reversed the horizontal and vertical sawtooths in their low voltage states.

My concern was the two images lining up so there would no image degradation resulting from over or off center scanning of the image tube’s defined target.

They aligned perfectly and I repeatedly switched the switch trying to create a failure in the camera and never could. I tried it with different image tubes in order to prove I just hadn’t gotten lucky. It worked on every one I tried. It forced the camera to start scanning in the lower right corner instead of the upper left corner.

As I recall I then made up three kits and sent one to Goldstone and the other to HSK. I installed the one in Sydney myself.”

– Dick Holl, March 2009.

See also:

Inverter swithc at HSK

The Inverter Switch on the Honeysuckle Creek Scan Converter just before the EVA – from a photo taken by Hamish Lindsay during Prime Minister John Gorton’s tour of the station.


Inverter switch at GDS

The Inverter Switch on the Goldstone Scan Converter on 4th July 1969. CBS News anchorman Walter Cronkite is interviewing Goldstone Apollo Station Deputy Director Dick Kephart.

Photo by Bill Wood. More photos here.


See also the Sydney Video page.


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