Early Color Television
TLS50. Based around the CTC-2B chassis (21-CT-55), with no modifications to the basic chassis, except to leave off the convergence yoke assembly. All the circuitry associated with the fantastic control panel is passive components, used to adjust the bias on the 3 CRTs, and set up the vertical and horizontal sweep and focus. The projection optics are 3 Norelco Protelgram boxes, with special versions of the 3NP4 CRTs, with blue, green and yellow phosphors, and a red Wratten filter.
The red green and blue filters in the protelgram projectors are the result of filters John Folsom inserted to try to project a color image using 3NP4 CRTs. He hasI two sets of the colored phosphor CRTs (special versions of the 3NP4), but has never been brave enough to try them, as it turns out to be very easy to crack the faceplate of the CRT by biasing too much beam current. He killed several B&W 3NP4s while playing with it. The projector can also be configured to project a B&W image using three 3NP4s.
Courtesy of John Folsom