Request for a 32 (and if possible a 30) line standards converter.

[DoctorWho]

Recently Darryl has said that it would be possible to design a standards converter for a 30 (or 32) line televisor for around £100.

I, like many other forum members, have bought one of the new "Baird Televisors" here:

http://www.mutr.co.uk/prodDetail.aspx?prodID=1420

The general opinion on these new televisors is that they are 32 lines.

Would it be possible to ask Darryl to consider making sucha converter avialable? I personally would very much like one to enable me to use the set to watch current over-the-air transmissions on it.

I did also wonder if it would be worth asking if it is possible to have a dual-standard converter, to cover both 30 and 32 lines, so that it will allow the new Televisor to be used, but would also be suitable for an original Baird 30-line Televisor shoukd one surface, or should a 30-line version be manufactured again?

Perhaps you may be able to comment here Darryl? Also, perhaps anyone else interested could also comment?

All the best,

Peter.

[tubesrule]

Hi Peter,
I have investigated creating a dedicated converter for this based on the low cost design. Doing some preliminary work, it would cost $205 including shipping (about £105 right now with the dollar so low). It would be capable of PAL/NTSC input and 30 Baird/32 NBTV output. I would have the options for positive or negative polarity output and gamma correction. I would remove all the audio and RF circuitry from the existing design. I could also include the ability to do the framing through a push button like I do on the Multi-Standard which makes framing the image much easier.
Unfortunately there have been a few postings about this on the NBTV site and elsewhere with no feedback to date, so I haven't taken it any farther. If there is sufficient interest in such a device, I would be happy to make them. Since they would need to be a special build from the regular low cost converter, I would have to get a fair idea of how many to make. Any feedback would be appreciated.

Darryl

[Panrock]

Darryl,

In the full knowledge I would probably be your only customer I'll throw this request into the pot. It would have to be straightforward for you to include though.

What about 30-line colour, supplied in simple R, G, B with a separate feed of syncs?

Getting rather tired of the current programme content consisting of Mickey Mouse, Noddy - and a 'Daz' packet for the commercial!

Happy Christmas

Steve

[ppppenguin]

Unless I've overlooked something I guess it would be possible to reprogram an exisiting converter to do 30/32 line output. The sound and modulator stuff would be redundant but this really doesn't matter. Whether there would be enough Xilinx capacity to make it switchable 405 and 30 is another matter.

There's also the not insignificant matter of doing the design work.

Darryl's original multistandard converter can do both 30 and 32 line "out of the box" but it's a lot more expensive.

[ianm]

Hi Darryl,

I would definitely be interested in a 30/32 line converter. Hopefully there will be enough interest from others to make this project viable.

[DoctorWho]

Hello Darryl,

Many thanks for your reply.

I would be VERY interested in a 30/32 line standards converter as soon as one could be made available. The cost is fine, are you in a position to take any orders now by any chance? You can certainly put my name down for one please.

Hopefully others interested will also reply so that you can see how many would be viable.

Thanks for your help with this.

Peter.

[tubesrule]

Hi Steve,
I had a suspicion this issue would come up I have followed your progress with 32 line color and the great results you have achieved. I am adding mechanical color support right now as a modification to a Multi-Standard unit for a project Steve McVoy is working on for his museum. He obtained a 60 line mirror screw assembly, and wants to run it in color. You can follow the progress on his web site.
That being said, I was able to do this because the Multi-Standard unit has an auxiliary port on it that I was able to add a daughter card with a multi-channel serial DAC. Even though these parts are not particularly fast, this one runs up to 30MHz which is fast enough for mechanical color. Unfortunately the existing low cost converter has no such provision and only contains a single DAC channel. A low cost unit could be designed with three DAC channels, but it would be a new design.

What I would propose for this device is the existing low cost converter with the audio and RF sections removed. This would leave the PAL/NTSC video input, the converted line level output, and the power jack. It would support both Baird 30 and NBTV 32 in the same unit. Since the NBTV standard provides full syncs, and the Baird standard provides black spaces between each line, no dedicated sync output would be needed.

Jeff is correct that an existing low cost unit could be reprogrammed to support this proposed new 30/32 firmware. I don't think it would be possible to support 30/32 and a regular standard like 405 in one firmware set do to limitations of resources in the fpga. This could be solved with a larger fpga part, but that would add cost.

Darryl

[DoctorWho]

This sounds like great news Darryl. I'll look forward to hearing how things develop.

Thanks for your help with this.

Peter.

[ppppenguin]

If Kat is following this thread, then her approach using a PC might be very relevant. I reckon you would use the audio output of a sound card rather than the video output of a graphics card.

[Dave Moll]

... sound's like a live video version of Gary Millard's AVI2WAV (or its younger colour sibling). I wonder how feasible that would be.

[jim_beacon]

Originally Posted by ppppenguin

If Kat is following this thread, then her approach using a PC might be very relevant. I reckon you would use the audio output of a sound card rather than the video output of a graphics card.

One of my projects for the new year is to see how slow the VGA port will go, but I suspect a lower limit will be around 180 lines. The other problem is the scanning direction - 30 and 32 go bottom right to top left in vertical stripes, "normal" TV goes top left to bottom right in horizontal stripes....... Still, I'll settle for standing the Televisor on end (and watching in a mirror)

Jim.

[tubesrule]

Originally Posted by Dave Moll

... sound's like a live video version of Gary Millard's AVI2WAV (or its younger colour sibling). I wonder how feasible that would be.

This is a very interesting standard that appears to interleave the color information into a single video channel. If this is the case, this would be possible to include in a converter.

Steve, I know you asked about full three channel color, but could this work for you?

Does anyone know the details of this format. I searched, but came up with very little information about it.

Darryl

[Kat Manton]

Hi,

Originally Posted by ppppenguin

If Kat is following this thread, then her approach using a PC might be very relevant. I reckon you would use the audio output of a sound card rather than the video output of a graphics card.

I am and that's what I was thinking of...

I've thought about doing live conversion. It's definitely possible, but I'm wondering if there's much value in it, to be honest. Given the aspect ratio and greatly reduced resolution, my idea was to write software for off-line conversion.

The idea is this. You load up a movie file to convert, then program a "pan and zoom track" alongside it as the movie progresses. Once you're happy with the framing of the movie, you export the movie as a multi-channel audio file containing sound and picture.

A 5.1 sound card has 6 audio channels; so it'd be possible to store and output R, G, B; a sync signal and stereo audio if needed...

Doing this will mean writing software from scratch. The MythTV-based FotH TV System uses software which already exists and was already doing almost what was required, so didn't take a lot of work.

It's something which might happen in time. It's yet another interesting thing on my list of things to play around with; but I haven't built or acquired a mechanical television set yet and I have many other projects on the go.

Cheers, Kat

[Panrock]

Originally Posted by tubesrule

This is a very interesting standard that appears to interleave the color information into a single video channel. If this is the case, this would be possible to include in a converter.

Steve, I know you asked about full three channel color, but could this work for you?

Not at present, since my system has always gone on its own merry way and blithely ignored NBTVA standards. For one thing I'd need to have new 32-line discs laser cut - my current system is 30-line with a square picture (which I personally prefer). However, there's no reason why I couldn't convert the system to run from NBTVA colour in future.

There doesn't seem to be much information published at present about the new R-B NBTV colour encoding standard. I can only suggest you try emailing Klaas Robers or Vic Brown through the email links on the NBTVA pages.

Steve

[tubesrule]

Thanks Steve. I missed that your sets have been the original 30 line standard and not the NBTV 32 line. The R-B NBTV system sounds interesting, but there is no substitute for full 3 channel color as you have done. This is what we're working on for the 60 line mirror screw project.

Darryl

[Panrock]

Originally Posted by tubesrule

This is what we're working on for the 60 line mirror screw project.

Darryl, I'm having trouble locating this interesting-sounding project on Steve McVoy's site. Do you have a direct URL by any chance?

Thanks!

Steve

[tubesrule]

Sure thing Steve. The main page is here: http://www.earlytelevision.org/color...ew.html#12-21a

I am very anxious to see what kind of results Steve M. gets from this project. The 30 line mirror screw sets I've seen operating are very impressive.

Darryl

[tubesrule]

Actually that last link I gave takes you somehwere to the middle of the page. The link for the start of the page is: http://www.earlytelevision.org/color_mirror_screw.html

Darryl

[Panrock]

Thanks Darryl, this is most interesting. I've got to be careful not to veer off-topic for this thread now, so I'll be ultra-brief!

I'd have probably not tried to persuade light from LEDs into optical fibres like Steve McVoy did, but would have tried a different approach, namely having a stack of narrow-angle ultra-brights some distance behind a vertical slit (probably bearing a perspex/frosted 'mixing rod') at the end of a light box, with the LEDs adjusted to beam toward the slit and mixing there. I would have thought this would be more efficient and give a brighter picture. It's a variation on the arrangement I currently use.

Steve

[DoctorWho]

I can only speak for myself here, but I would personally like a real-time standards converter to allow me to view over-the-air transmissions on 30-lines, rather than only being able to view PC converted footage.

Peter.