Narrow-Bandwidth Television Association

In the newsletter Vol. 31 No. 4 Jeremy Jago showed an inspired bit of lateral thinking in the article "New Display Method". The outcome of which is on a CRT display you have two images, one positive, the other negative. See CRT Jeremy 1.gif.

Thinking further, the negative image, although novel, is pretty useless. So I thought about using that time of the negative image to provide a waveform function. See CRT Face 1.gif.

To the left of the positive image is displayed the waveform of the video complete with cursors marking sync, black and white levels. The cursors are shown in blue, but of course would be green on a conventional scope tube.

I have shown it on a round CRT face as rectangular ones weren't around in the period. Neither were transistors, but I'm going to take some licence there.

My question is this....would there be any interest in this?

Steve A.

The clever trick of Jeremy Jago is that he needs no intensity modulation and still displays grey scale infoemation, but now in duty cycle modulation.

I don't see the duty-cycle modulation in the wave form picture. Yes of course you can do this, make two not identical pictures on one oscilloscope screen, but then again you need intensity- or Z-modulation.

Jeremy could also place the negative picture outside the visible area of the screen, but at least for the Convention it was a good idee NOT to do that, so everyone could see and hopefully understand what he was doing.

Klaas Robers wrote:The clever trick of Jeremy Jago is that he needs no intensity modulation and still displays grey scale infoemation, but now in duty cycle modulation.

Agreed.

Klaas robers wrote:I don't see the duty-cycle modulation in the wave form picture. Yes of course you can do this, make two not identical pictures on one oscilloscope screen, but then again you need intensity- or Z-modulation.

No, what I'm thinking of requires no Z-modulation which is why I found it to be such a brilliant bit of lateral thinking.

Klaas Robers wrote:Jeremy could also place the negative picture outside the visible area of the screen, but at least for the Convention it was a good idee NOT to do that, so everyone could see and hopefully understand what he was doing.

Yes, understood. What I'm thinking of is that instead of having the negative picture one has a waveform display instead. The drawing was just a conceptual one, not really being representative of the final product.

But before I go ahead with this I need to re-build my NBTV CRT display, so don't hold your breath!

Steve A.