Narrow-Bandwidth Television Association

Today I've got a MUTR Televisor, just as a "reference model" for testing. The assembly was easy, and I saw the built-in testcard. But the picture wasn't stable, so I pushed the disc a little bit nearer to the opto-fork. But now the monitor seems to go mad: The motor is pulling up, and the speed-control seems not to have any effect. After pulling the disc back, everything is fine again, but the picture is "wobbling", more than on my big monitor, still without any electric synch-circuit (I've got today the necessary MOS-fet, but I had another toy to play with. )

BTW: The single LED spends more light than expected. Nevertheless I will replace it with a white one, and I have to experiment with the diffusor, as others mentiond before.

I have experianced the same problem of the disc being too close to the sensor and causing "run away", this is compounded by the fact that the disc will distort even with moderate temperature variations, so a gap one day will not there another.

My solution was to have the discs on both my models on the end of the spindle and to increase the case spacing accordinly, this does not seem to cause any problems - I run one fully enclosed in a cabinet and the other is fully exposed - both perform identically when driven by a 630 / 32 line converter, lock is unwavering allowing feature films to be watched, Pygmalion (the 1938 Leslie Howard version) offers good viewing as it has a reasonable amount of face close ups with dialogue.

I have only just modified the diffuser from the original and the results are fantastic - the extra detail is most welcome - the modified diffuser I have made uses clear plastic that I have lightly sanded, I was thinking of trying a glass microscope slide and grinding it lightly with grinding paste - has anyone tried anything else ?

The diffusor was the second thing (after changing the battery with a transformator) I've done to the monitor. A big improvement!

I wanted to replace the LED with an ultra bright one, but the new LEd died after a few seconds, so I've built in the original one again. I wonder why that happend. As I heard, others had replaced the LED succesfully?

Originally I've bought the monitor to have a small monitor for testing next to my computer and for showing to other people how it works (my "big box monitor" is currently getting a big wooden cabinet), but I have ideas to make a nice transistor-radio look televisor from the MUTR monitor. Has anybody seen the Dr. Who episode "the idiot's lantern"? The doctor uses a portable TV climbing up the tower at Alexandra Palace which is looking very fifties, but wasn't possible in that time. Something like that would be a nice housing for the MUTR monitor.

DrZarkov wrote:the Dr. Who episode "the idiot's lantern"? The doctor uses a portable TV.

How about this one used by "Mr Magpie":

Yes, exactly that one! I hope it will not be too huungrrryyyy!

Reading the new newsletter Vol. 32 No. 4 I ask me how did Vic Brown changed his to a colour monitor? He had to change almost everything I think? Are there any circuits for an NBTV colour compatible system available?

I've not yet read the newsletter, but what I recall from the convention was that the MUTR was driving the disc (including sychronisation) and the LEDs were driven from external hardware. I'm open to correction, though.