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Early Color Television

RCA Colorama Flying Spot Scanner Restoration

Cliff Benham is restoring the scanner. Here is his progress:

March 22, 2015

After replacing caps, fixing broken wires in the Jones plug cable and repairing the intermittent delay line connection several times, the Colorama is sort of making pictures. No blue but red and green are there.

I still need to align the colorplexer but cannot do that because after troubleshooting for a day, I found the Blue photomultiplier tube is bad. I found two NOS 5819s on eBay for $40 each. but they won't get here for a week. That I found them at all is surprising to me.

The slide in the attachment is the only one I recognize as a legit test slide from the 60s. All the others look like they were taken on someone's vacation. There are test slides mentioned in the setup procedures but there are none of these slides. TV stations would have them unless they were thrown out with the film chains.

I need a window slide, color bar slide, gray scale slide and a test pattern slide with a circle for deflection alignment.

When I picked up the two cases last year, they were pretty damp because they had been sitting in a carport for ? don't know how long.

I let everything dry out for a month, then started bringing up the unit on a variac over the course of two days. Nothing blew up or overheated, but nothing worked either.

Spent a month replacing missing hardware and tightening up everything. The optical assembly hod just one screw holding it in place!

Lots of De-Oxit in tube sockets and connectors helped get things working. Aligning the sync generator took a day. Nothing works unless the sync gen is exactly right.

The slide changer works, the transition from B&W to Color works, and the RF modulator works on Channel 3.

Wayne Bretl is loaning me some setup slides so I can do the alignment 'by the book' of the color per-plexer.

The literature indicates two sets of slides, one set for setup and another for demonstrating color. The 6 slides that were in the scanner are the color demonstration slides and there were no test slides. I have asked several people for help finding test slides. I found a company online that will make 35mm slides from any file I send them. I'm going to have them make a few slides including color bars, I and Q and a composite color slide.

March 29, 2015

With a new Blue Photomultiplier tube installed, all three color channels of the Colorama are working.

Wayne Bretl sent some alignment slides so the image linearity is now correct and the EQ for each channel is correct with no more overshoot or ringing.

The final step is to align the colorplexer circuits. I had some digital images made into color slides by a company in Florida. They should be here this week. The slides match those mentioned in the setup and operation paperwork that came with the Colorama.

March 30, 2015

Got the color slides today and found out why the color looks so strange: There is no modulation in the  Q channel. So, no green or violet. I channel is fine though.

April 7, 2015

The Colorama is making good color pictures.

Solved the encoder and CRT linearity problems.

Many mechanical adjustments to the CRT yoke, the optical relay lens mount and the rotating slide disk position.

Now tweeking the sync generator to find the best settings for the divider chain for best stability.