View Full Version : Professional color television monitor from 1970
yagosaga 02-21-2006, 11:45 AM 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/archiv/tv/fernsehgmbh/img/MC47_3BAfirstLight.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?
Sandy G 02-21-2006, 01:00 PM Wow....that bad boy is REALLY something, especially compared to the rat's nest you usually see inside a TV...-Sandy G.
jpdylon 02-21-2006, 01:07 PM THat is absolutely awesome. Probably one of the best built monitors at a glance. The modular design rocks. I would never have thought a hybrid setup would be used in the professional world. perhaps the transistors were not reliable enough to use as the HO and HV yet.
Very cool.
yagosaga 02-21-2006, 01:39 PM I would never have thought a hybrid setup would be used in the professional world.
This monitor was developed and designed in 1965, two years before color television started in Germany. At that time only the Telefunken brand had developed color television technology. Compare the flyback of the monitor with the first commercial color tv set:
http://bs.cyty.com/menschen/e-etzold/archiv/TV/telefunken/img/netzteilpalcolor.jpg
It is the same. And here, the PAL delay line unit
http://bs.cyty.com/menschen/e-etzold/archiv/TV/telefunken/img/ffs1967pal.JPG
is the same as used in the professional monitor.
captainmoody 02-21-2006, 06:11 PM The deflection yoke assembly looks suspiciously like an RCA unit...
Sandy G 02-21-2006, 06:37 PM What kind of shape is the CRT in? Looks pretty good, but of course, that doesn't mean anything. Is it a std CRT, or a special one ?-Sandy G.
yagosaga 02-22-2006, 07:54 AM The deflection yoke assembly looks suspiciously like an RCA unit...
I think it is an RCA type. The developer of this monitor told me, that they imported RCA picture tubes for this monitor. The Germans were not able to produce professional color picture tubes in these days.
Is it a std CRT, or a special one ?-Sandy G.
It is no standard CRT but a special one. The screen surface is somehow rawer than usual. The phosphor dots are much smaller than those of standard CRT's. And the red phosphor is deeper-colored than in contemporary standard tubes.
wiseguy 02-22-2006, 08:48 AM Hey yagosaga.
you may have to loop the composite video thru the sync input in order for the composite video to work,I have a couple of old broadcast monitors that work like that,and require ext sync even for the composite video,those usually were fed sync or blackburst from the studio's house system, those monitors are heavy..!
I had an RCA version that i could not carry myself..I wish i would have kept it but it had been on and cooking 24hrs in a studio for like 18yrs.
yagosaga 02-23-2006, 01:56 AM you may have to loop the composite video thru the sync input in order for the composite video to work.
I have used several video input sources. With terestrial tv broadcasting, it didn't work. The sync didn't lock in and the picture is somehow blurry. With the video test signalgenerator, it worked. And now I have found that it works with my second DVD player. Sometimes iif the picture is darker, the synchronisation did not lock in. Perhaps the monitor needs a stronger video input signal than provided by today's video sources. I am waiting to get the schematics. The composite video input still does not work. I use RGB with sync input (loop).
yagosaga 02-26-2006, 09:29 AM Hey yagosaga.
you may have to loop the composite video thru the sync input in order for the composite video to work
Hey wiseguy,
the monitor is working now with an excellent picture and beautiful colors. The CRT has the original EBU posphors:
http://bs.cyty.com/menschen/e-etzold/archiv/tv/fernsehgmbh/MC47_3BA.htm
The photos can't reproduce the amazing picture in original. And the solution was quite simple. I have followed the input signal with a meter to find the path of it in the circuits. In this way I found that the composite video module has an RGB and sync output on the back of the monitor. I have noticed the RGB output before but thought that this is for external sources.
It was obviously, but I didn't recognize the function of it. I have only to loop the RGB output of the composite video module thru the RGB input of the monitor. And then it works. :banana: It is so simple :bash:
old_tv_nut 02-26-2006, 06:06 PM Beautiful!
Sandy G 02-26-2006, 06:16 PM That is a GREAT picture ! Excellent work ! You REALLY have something to be proud of- Between that & yr CTC-5, I'd say you have one of the finest TV collections in Germany...What OTHER goodies do you have?-Sandy G.
bgadow 02-26-2006, 10:02 PM Outstanding! Isn't it a joy to work on something that is built this well?
You don't see many old professional monitors. Most seem to be used heavily and then scrapped.
yagosaga 02-27-2006, 02:59 AM Hi AK'er, thank you for your numerous comments and acknowledgments.
You don't see many old professional monitors. Most seem to be used heavily and then scrapped.
This monitor belonged to the technical university here in Brunswick, and it was property of the government. I think that they didn't run this monitor very often at the university. There is not much dust in it, and the picture tube seems still very strong. I will test it with the crt meter today.
Outstanding! Isn't it a joy to work on something that is built this well?
This is my first professional monitor I had on the bench. I am still impressed about this elaborated and servicefriendly circuits. This professional technology shows what is really possible. The commercial sets I have seen before are a compromise between quality and costs. When I find time in the next weeks I will write a documentation about it for the web with an English translation.
That is a GREAT picture ! Excellent work ! You REALLY have something to be proud of- Between that & yr CTC-5, I'd say you have one of the finest TV collections in Germany...What OTHER goodies do you have?-Sandy G.
Look at this page
http://bs.cyty.com/menschen/e-etzold/archiv/TV/tv.htm
and click "Start". All listed sets with an an asterisk are part of my collection. But I have reached a limit, there is no more space in the house, and in summer we get our third child. I have to put some tv sets on the attic of my parents and will keep here only the most interesting sets.
P.S.: I have just telephoned with the engineer, who created the deflection units of this monitor. He told me, that 1500 monitors were built in 1965-1970. Each of them costs 18,000.00 Deutschmarks (for example, the Volkswagen 1300, a car, costs 5,150.00 Deutschmarks in these days). I have an exemplar with an NTSC module.
These monitors were exported in the whole world. (The SECAM models should reproduce better SECAM than the French aequivalents ;-)
Yesterday he saw some monitors of them still working in a Iranian nuclear power station in the evening news. I found a video of it still on the web and made a screenshot:
http://bs.cyty.com/menschen/e-etzold/archiv/tv/fernsehgmbh/img/MC47inIran.JPG
The black-designed monitors have the SECAM module inside. Incredible, hybrid tube-transistorized monitors are still in use today. :D
kc8adu 02-27-2006, 08:13 AM a friend down the road has a similar looking unit packed away from a move.
he got it when whio tossed some stuff in the late 70's
i get to revive it this summer.
i will post pics here too.
would be neat if its the same unit you have.
a foreign unit with an rca jug and yoke bucket.cool.
yagosaga 02-28-2006, 07:35 AM a friend down the road has a similar looking unit packed away from a move.
These monitors were exported into the U.S. in the 1960's and 1970's. The engineer told me that he was with it on an exhibition in the General electric laboratories, to introduce the monitor. The American engineers were impressed. But after he returned to Germany, he got a message, that this monitor could not sold in the U.S.. The x-ray emission was exorbitant high.
The Germans had no experience with the shunt regulator and the x-ray shielding. They had to insert a piece of sheet metal around the PD500 to lower the x-ray emission. Some of the shunt regulator tubes got so hot that the glass melted.
In the television factory, they had a large hall where they tested the color picture tubes. More than thousand tubes were tested at the same time for shorts inside the tubes. They were driven with 30,000 volts continuously for four weeks, provided by a simple test-chassis with shunt regulator. After the test the tubes were installed into the tv sets. Some of the engineers, which worked with the picture tubes died because of high x-rays in these days.
yagosaga 05-11-2006, 03:21 PM I have measured the emission of the crt (RCA 1842P22). On the red gun I measured 0.7 mA, blue and green have 0.5 mA. What do you think, is it OK? My crt meter tells that 0.5 is at the borderline between good and bad.
Eckhard
jpdylon 05-11-2006, 03:34 PM As long as it will make a grayscale picture and the guns aren't bleeding it should be OK.
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