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-   Television Standards Converters, Modulators etc (https://www.vintage-radio.net/forum/forumdisplay.php?f=95)
-   -   Standards Converter/modulator info wanted (https://www.vintage-radio.net/forum/showthread.php?t=935)

tvden 23rd Aug 2004 4:44 pm

Standards Converter/modulator info wanted
 
Hi all having now gotten reinterested in TV via my radios and aquired a few sets none of which I have started on yet but I hope to soon, I now am faced with the prospect of geting something to put on the screen can members of the forum tell me what they use to get pics and sound, it seems to me a modulator is a lot of work for very limited viewing as you have to get suitable tapes, and the only readily made standards converter available at the moment is the Domino no disrespect but its quite expensive regards Den

evingar 23rd Aug 2004 5:17 pm

Re: Standards Converter/modulator info wanted
 
Hi Den

I have a Pineapple standards converter that I built from parts left over from the original project (along with some I had to find myself). The major advantage to me of this was the fact that I had a ready-made PCB. This cut down the time taken to do the task no end and removed the chance “whiffly” errors due to poor circuit layout!
(In my experience strip board construction is a nightmare for such things – no matter how careful you think you are being!).

You comment on the Domino being expensive, well I guess it all depends on what your point of reference is. Coming from a broadcast electronics background, I don't consider it to be so. After all, it's comparable to a cheapish hi fi set up, or a cheap break holiday.

The cost in components of tiny production runs is colossal compared to " consumer " electronics; this is because the price of absolutely everything in them is " loaded " through lack of economies of scale. Usually for small production runs you have to buy from " retail " suppliers like RS or Farnell, no one else is really interested in supplying the quantities you want - and boy do you pay through the nose for components from general suppliers like the above: -[ I would be surprise if Domino makes all that much from their units to be honest !

If you don't want the cost of a standards converter, an alternative is a test pattern generator and a modulator. With this, at least you don't have to keep reloading the tape! The Dinosaur team produced an excellent product a few years ago. You could buy a selection of different test patterns on EPROM that could be plugged in and selected. Some real “blasts form the past” were available! I have one of these also and fully recommend them. Maybe someone would be willing to sell you a second hand one - worth asking I guess.



Chris

ppppenguin 23rd Aug 2004 5:36 pm

Re: Standards Converter/modulator info wanted
 
Evingar is correct in his assessment of prices. I think that about 50 Dominos have been made so everything has to be bought in small volumes. This is much more expensive than buying in the huge volumes that are common for consumer equipment.

My own work is largely concerned with designs that will be manufactured in 100s. My clients and I look enviously at the cost of components for 1000s. I'll feel ill if I find out about 100,000+ prices.

Malcolm is certainly not making much profit on each Domino. Even if his time is given for free.

Richard Russell makes a newer test card generator. It can be programmed with many patterns using a PC. I have seen it working at 625 and it's a nice little unit.

http://www.cix.co.uk/~rrussell/

oldeurope 24th Aug 2004 8:04 am

Re: Standards Converter/modulator info wanted
 
Hi Den

I use a SONY AVC-3250 Video Camera.
It is modified for dual standard.

VHS- video is a good source too. ;)

I made a standards converter and a modulator.
You can find infos here:
http://www.your-normwandler-page.de.vu :)

Kind regards

Darius

tvden 24th Aug 2004 8:57 pm

Re: Standards Converter/modulator info wanted
 
Hi all I am taking on board all you say, I must admit I did not think of small production runs costing a lot more money, it would have been great if they could have been mass produced !!!can anyone tell me can I still buy a pineapple standards convertor I think they were about £200 why were they cheaper ?? regards Den

Paul Stenning 24th Aug 2004 9:51 pm

Re: Standards Converter/modulator info wanted
 
Someone was selling PCB-only Pineapple converters (or was it Dinosaur converters?) a while ago, which would have been cheaper as there is no case, PSU, connectors etc. I don't think they are available now though.

mjizycky 24th Aug 2004 11:20 pm

Re: Standards Converter/modulator info wanted
 
Quote:

Someone was selling PCB-only Pineapple converters (or was it Dinosaur converters?)
Certainly not Dinosaurs, that's a fact! No, it was the Pineapple.

I have to back up Evingar's comments to 'bsaden' re the pricing of the Domino converter; when Dave and I were making the Dinosaur I fielded questions from someone who accused us of being " rip-off merchants " as he could get " converters from my local shop in Hull for a tenner " . Once I'd established I was dealing with a complete moron I pulled his argument to pieces before telling him precisely what I thought of him!

(I should add that he wasn't the only one - when I asked someone what they thought was a fair price for the converter and they replied " it should be fifty quid " I produced £50 from my pocket and said " go build me one then " . They didn't take me up on the challenge.)

Like Evingar, I too come from a broadcast background - and believe me, £400 for a specialised product like the Domino/Dinosaur is an absolute pittance, when you consider the prices the " real world " manufacturers realise for their product. If anything, the Domino should be at least twice the price as that, IMHO, is far more realistic. After all, it's the cost of a pair of TV22s these days...

If you think it's easy, take a quick look at http://www.snellwilcox.com/knowledge.../estandard.pdf which explains the principles of standards conversion. At least with 625 -> 405 you don't have to get into temporal interpolation!!

You need a modulator at least to get viewable pictures on a 405-line set; you weren't planning any naughty modifications to tap straight in to the set, now were you?

ppppenguin 25th Aug 2004 8:26 am

Re: Standards Converter/modulator info wanted
 
Mike is absolutely correct though there is a small possible exception. If he costs his time and effort as free of charge then Darius's converter could probably be built and sold as a fully engineered product on a PCB in a box for quite a lot less than £400. I don't intend to do a full costing but I guess it would still be hard to get it under £200 once you have paid for a PCB, case, PSU etc.

peter_scott 25th Aug 2004 10:56 am

Re: Standards Converter/modulator info wanted
 
Mike´s paper gives a nice clear interpretation of the subject but greatly overstates the amount knowledge required to build say Darius´converter. Most folk will not be looking to convert from one colour system to another
either.

I may be forgetting the bits I had kicking about but 200 pounds seems to me a very generous parts budget for Darius´converter.


Peter.

tvden 25th Aug 2004 4:37 pm

Re: Standards Converter/modulator info wanted
 
Hi all for myself I only need a standards convertor for 405 line I am not going to start buying different standards sets from all over the world,if I could get a standards convertor for arround £200+ I would be more than happy to buy one regards Den

Paul Stenning 25th Aug 2004 7:28 pm

Re: Standards Converter/modulator info wanted
 
Well it sounds like your choice is to either build the Darius one yourself, which will cost you less than £200 in parts, or buy a ready-made Domino one for £400. I don't think you are going to find a ready-made one for £200!

Danny 25th Aug 2004 11:09 pm

Re: Standards Converter/modulator info wanted
 
hi all it takes me a day to build a modulator from scratch?.
Has anyone done a pcb yet for the darius converter?.
It would probrably take me a week to build it though
so at about £80.00 for a days wages makes the domino
very cheap.
plus the cost of the parts and the box to house it in :D
You could still use a cammera and make videos or get
some nice fellow to record some 405 line programs
for you.
You would still need a modulator to convert the video to
VHF though. ;)

tvden 27th Aug 2004 12:37 am

Re: Standards Converter/modulator info wanted
 
Hi Danny can I get a camera on ebay if so what should I look out for, I take it I put the camera in front of a 625 line tele and record to a video recorder means I need a 405 line camera or can a 625 line camera be modified to 405 dont know much about this side of things regards Den

oldeurope 27th Aug 2004 4:47 pm

Re: Standards Converter/modulator info wanted
 
Hi Dennis
It was a lot of work to modifie my AVC3250CE.
If you get one I can sent you the diagrams.
It is the same work to change a 625 TV to
dual standard.

Darius

murphymad 2nd Sep 2004 10:27 am

Re: Standards Converter/modulator info wanted
 
Hi Dennis, All,

Well I have replied to your request for a pattern generator but I think you will be very disappointed with just watching a couple of black bars down the screen and a buzzing tone from the speaker of a nice 405 line TV.
And Hay, how much will it cost you to restore/repair the pattern generator? Time? and that's after buying one.

Don't waste any more of your time on this and get a well made guaranteed to work first time, fully built unit that is not subject to still needing to find/build a modulator and a case and a power supply (on top of your £200 purchase price), import tax (if bought from outside the UK, customs charges and VAT, post office handling... will be added before you can get your hands on it). Need I go on as importing alone will add the best part of 100 quid to the total cost.
Get a Domino!
Look back at your Bank statements and see what you 'still have' for the last 400 quid you spent. (This is a statement and not a question)

I was told this week that the Domino will cease to be available when the current component stock is exhausted. The reason being, that if you could supposedly get one from elswhere for around £200, why should they continue. So anyone wanting one had better be quick about it as I do not know of ANY other source of a fully built and tested unit ready to go and available now!

I have made my feelings known to the maker, about ceasing the production of the Domino.
I have explained that I think this is a mistake, but unless there is support for continuing, it looks like it will become extinct. Just like the Dinosaur!
Mike...

ppppenguin 2nd Sep 2004 10:53 am

Re: Standards Converter/modulator info wanted
 
Never mind all the technical arguments, Mike is right. If you want to run your 405 TVs easily and without any hassle then then £400 spent on a Domino is good value. Otherwise if you are interested in tinkering with modulators, cameras etc then go ahead.

The Aurora converter has not yet gone into production and may or may not do so. It does not have a modulator so you still have to provide that for yourself. Take £300 or so for the converter, add import duties and a modulator and you've reached £400. The Aurora will be an excellent solution for those who want other standards apart from 405. Darryl has discussed the possibility of a 405 only version with modulator. This was a theoretical discussion - I hope I am not misrepresenting Darryl when I say this is not very likely to be built.

I will be demostrating the Aurora at Harpenden on Sunday. I hope to show both 405 and 30 line outputs.

tvden 2nd Sep 2004 6:55 pm

Re: Standards Converter/modulator info wanted
 
Hi all I have read with interest all your arguements in favour of a Domino re other methods !!! and you all know more than I do so you have now convinced me not to muck about and to buy one, I can see even if I try to make one it will be a struggle and to be honest would prob take me a long time, I hope to have saved enough money in the next few weeks to order one as it has to be paid for upfront so my thanks to all that have joined in this discussion regards Den

evingar 2nd Sep 2004 10:22 pm

Re: Standards Converter/modulator info wanted
 
Quote:

I have made my feelings known to the maker, about ceasing the production of the Domino.
I have explained that I think this is a mistake, but unless there is support for continuing, it looks like it will become extinct. Just like the Dinosaur!
From an enthusiasts point of view I agree, I would certainly buy a Domino tomorrow if I had no standards converter myself. I just " missed the boat " on the Dinosaur, by “faffing about”, something that I " kicked myself " about at the time, Luckily, I then managed to get some parts and a PCB to build a Pineapple converter, a clever, efficient design (but too much done in the analogue domain for my personal liking) however, I digress.

Looking from a hard headed point of view though, I am not sure what the market is for 625-405 line standards converters. As discussed elsewhere here, some (not I!) consider them expensive because of the small production runs that can be supported. The cheaper alternative of 405-line material recorded on a suitable VCR and played back through a modulator is probably what such folks will opt for. Additionally, because the likes of Dinosaur and Pineapple have gone before, some of us that crave such things are already satiated. I suspect that the Domino design may be superior to my Pineapple (I can’t comment on the Dinosaur product) but it is difficult for me to justify further expenditure in this area for a possible marginal improvement in quality.

I summary, I too think it’s a shame that Domino is ceasing production, but I also strongly suspect that production of such units is not economically viable, especially if the time of the producers were to be commercially costed. I think it’s great that Dinosaur, Pineapple and Domino units have been produced at all. If making money was the sole aim of these folks, they must surely have known that there were far easier ways of doing so rather than producing products for such a small specialist hobbyist market where the prices they can charge are capped to unrealistic levels. When these folks decide that they have had enough of “working for peanuts”, I therefore cannot really bring myself to criticise them too much.


Chris Garnett


Ian_K 2nd Sep 2004 11:36 pm

Re: Standards Converter/modulator info wanted
 
It accurs to me a cheeper, easer to relise solution may be to create a converter attachment for a computer ether an adaptor that connected to the video out or perhaps a custom PCI card. This would mean a 20 pound off the shelf PCI TV card would be all that was needed for the converter input The conversion it's self should be achievable in software these days.

ppppenguin 3rd Sep 2004 7:47 am

Re: Standards Converter/modulator info wanted
 
This suggestion of using a PC to do conversion has been made many times before. There has not been any noticeable success using this approach. Until recently there was not even a hope of doing it this way.

The conversion algorithms are trivial in software. But try actually doing them, taking in the video data at full speed, doing the conversion algorithms, and outputting the 405 data, also at full speed.

One approach that could be workable is programming a special mode on a graphics card. A colleague once did a 405 output mode for a BBC " B " . He has also implemented non-standard graphics modes on standard PC graphics cards.

Using a modern graphics card with video replay facilities and custom output modes could be feasible. The PC would actually be doing relatively little, most of the work would be on the graphics card.

When you start adding hardware things start to get tricky. I have customised graphics cards for some specialist applications and can assure you that they are not the easiest things to work on. A custom PCI card will suffer from all the same low voume/high cost troubles as a complete converter. Having designed PCI cards myself I am well aware of what's involved. I'm sure that Darryl (tubesrule), who has much more experience than me on PCI cards will confirm this. The only way to make PCI cards cheaply is to make lots of them.

And remember that even a modest PC will cost as much as a Domino. Do you really want to fire up a PC every time you want to use a 405 TV?


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