Professional color television monitor from 1970

[yagosaga]

Before two weeks I have bought an old studio television monitor for EUR 5.00. It is a Class 1 monitor and it was made by the Fernseh G.m.b.H. in 1970. Tubes were used in the horizontal output unit (PL509, PY500, GY501 as high voltage rectifier and PD500 as shunt regulator. The other parts are solid state. It is the first time I got a professional television monitor. Inputs are: R, G, B, Y, Sync and composite video. The composite video unit has a switch for PAL to NTSC.
One PY 500 was missing. After replacing it, I found that the PL509 is bad. After replacing this, I got high voltage, but no picture. There is a negative voltage at the first grid of the crt. It is a 1842P22. Now I am looking for the schematics. But it is very difficult.
Meanwhile I got the luminance channel working, but no sync:

http://bs.cyty.com/menschen/e-etzold...firstLight.JPG

With a video-test-signalgenerator I got a steady picture. And with a DVD video signal at the input of the video-test-signalgenerator I got a moving television picture.
The composite video unit is not working. Without schematics it is difficult to get this monitor working. But it is a very nice peace of early professional color television technology. Does somebody here has informations about professional video standards in the late 1960's or 1970's?