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-   Television Standards Converters, Modulators etc (https://www.vintage-radio.net/forum/forumdisplay.php?f=95)
-   -   Future Supplies of Standards Converters?. (https://www.vintage-radio.net/forum/showthread.php?t=171271)

Chris55000 21st Sep 2020 10:57 pm

Future Supplies of Standards Converters?.
 
Hi!

One point that's crossed my mind recently is that new Members who wish to begin Analogue TV Restoration, both early post–war and early–CTV-era models, may only have a very limited time left to purchase suitable line–standards/digital–to–analogue converters!

I believe the maker of the Aurora has said there are now only twenty–five of the special FPGA devices now used in this remaining, after which production would have to cease, Darius's design uses CCD/interpolation chips made out of total unobtainium, and I have personal misgivings about the future life of the Hedgehog/Dinasours designs for the same reasons!

Me thinks a new design needs to be started using devices that are still in plentiful supply and/or still active production, and above all, I am of the opinion that any new design should be open and not exploited purely for commercial gain!

This is the reason, as well as cost and space limitations, why I have never been interested in this aspect of our hobby, tho' I still have the fault–finding knowledge, it has hardly ever been called for since I joined in 2006 or thereabouts!

Unfortunately I was not taught advanced design and r.f. skills, so regrettably following Darius's footsteps is a no–no for me!

Opinions?

Chris Williams

peter_scott 22nd Sep 2020 6:45 am

Re: Future Supplies of Standards Converters?.
 
The Auroras and Hedghogs out there will no doubt prove to be very reliable and the number of old sets will not grow significantly and standards converters are not the only way of generating old standard signals.

Peter

jjl 22nd Sep 2020 7:50 am

Re: Future Supplies of Standards Converters?.
 
FPGAs are in very widespread use in all sorts of high volume systems and are likely to remain that way for decades to come.

As far as I understand it, there are two problems with the Aurora design in that the FPGA used is becoming obsolete and that the video decoder devices used are also proving hard to source - if there is no longer any analogue broadcast TV, why would the manufacturers continue to make such devices.

In principle, it should be straightforward to port such a design to a current FPGA type but the newer FPGA would be highly likely to have a different pin-out and package type, so a new PCB design would be required. The video decoder issue is a bit more challenging, but in principle, with a fast ADC and the decoder processing implemented in FPGA logic, this should be solvable. I believe that Frank Cuffe - the Hedghog designer has been thinking about this.

I think that FPGAs are now the only practical way to go for standards conversion and in many ways the standards conversion problem is becoming easier to solve as current FPGAs can be found with fast ADCs and large amounts of on-chip memory so external devices can be eliminated. The challenges are that such devices come in BGA packages and often require multiple power supplies with well defined power sequencing. This can be solved by purchasing a ready-made module containing the FPGA and its power supplies.

John

ThePillenwerfer 22nd Sep 2020 1:20 pm

Re: Future Supplies of Standards Converters?.
 
Quote:

Originally Posted by peter_scott (Post 1291586)

The question that gives rise to is: How long are VGA graphics cards, especially ones with two ports, going to be available for? VGA is another standard that's in its twilight years.

The best future-proof converter would be one that takes an HDMI input and outputs it as 405.

FRANK.C 22nd Sep 2020 3:28 pm

Re: Future Supplies of Standards Converters?.
 
Personally I don't think there is any danger of us been without standards converters as none of the potential problems raised are insurmountable.

The Hedghog II uses the TVP5150 video decoder. It is available from RS, Farnell, Mouser, etc. As far as I know is still in production. It uses a EP4CE6E22C8N FPGA which is in current production. The MC44BS373 modulator which it uses has been out of production for years but is still available from China etc. The Hedghog or Hedghog II can be built without the modulator and used with an external modulator.
Using the MC44BS373 is not ideal when it is no longer in production but there is no other chip that I know of that comes any where near what it does. There are other ways of modulating a TV signal including doing the modulating within the FPGA. But there is none that I know of that can give the range of channels, is as cheap and is a easy implemented as the MC44BS373.

I am currently doing some work on a programmable standards converter. When completed it should be able to generate any standard with a 50Hz field rate. If it is to have a modulator I will most likely use the MC44BS373.

In my opinion I don't think that there is any point in doing things a harder more expensive way when there are chips like the TVP5150 and MC44BS373 still available.
When they are no longer to be got we will find a way around the problem then.

If anyone is thinking of designing a standards converter this thread on Golborne Vintage Radio Forum would be a good read. In it Jeffrey Borinsky gives all the information needed to design one.

Anyone can build a Hedghog or Hedghog II just follow the link below for all the information needed.

Frank

Freya 22nd Sep 2020 7:00 pm

Re: Future Supplies of Standards Converters?.
 
There is plenty of interest in Hedghog II standards converters.
Sales suggest to me that there are plenty of new people getting into the hobby as well as those who need yet another converter.
Quite a high percentage only ever use converters on a single set.

greg_simons 22nd Sep 2020 10:57 pm

Re: Future Supplies of Standards Converters?.
 
Quote:

Originally Posted by Freya (Post 1291804)
There is plenty of interest in Hedghog II standards converters.
Sales suggest to me that there are plenty of new people getting into the hobby as well as those who need yet another converter.
Quite a high percentage only ever use converters on a single set.

Like me!, this thread has reawakened my interest in building one, and getting another one or two 405 line sets, a nice kb vc1 would be nice...
Greg.

FRANK.C 23rd Sep 2020 6:41 pm

Re: Future Supplies of Standards Converters?.
 
Quote:

Originally Posted by ThePillenwerfer (Post 1291705)
The best future-proof converter would be one that takes an HDMI input and outputs it as 405.

Yes it would be a good way to go but one of the problems with using HDMI as an input to a converter is licensing and the cost of.
HDMI to composite converters that could be used before the standards converter are not expensive.

Frank

Courtney Louise 24th Sep 2020 5:42 pm

Re: Future Supplies of Standards Converters?.
 
Does anyone sell a full DIY kit for the Hedgehog II?

FRANK.C 25th Sep 2020 4:38 pm

Re: Future Supplies of Standards Converters?.
 
I don't know of anyone doing a complete kit of parts. If it is any help I have a few spare PCB's.

Frank

AdrianH 25th Sep 2020 7:50 pm

Re: Future Supplies of Standards Converters?.
 
Is VGA output the only one that will work with computer modelines or whatever it is, can one not use other outputs such as HDMI, Displayport, DVI etc. I have a computer with mini display port outputs and have a converter to give me the old VGA, simply because I still use a KVM swicth.

Was the modeline restricted to just VGA? Just wondering because of the comment from ThePillenwerfer.

Adrian

greg_simons 25th Sep 2020 7:52 pm

Re: Future Supplies of Standards Converters?.
 
Hi frank
Yes, i would be delighted to relieve you of one of those boards, I'm definitely doing the thing.
Greg.

ThePillenwerfer 25th Sep 2020 8:21 pm

Re: Future Supplies of Standards Converters?.
 
Modeline works on DVI but the signal coming out of the socket is digital.

Richard_FM 25th Sep 2020 9:40 pm

Re: Future Supplies of Standards Converters?.
 
I did wonder how much demand there is for converters, certainly there are plenty of 405 line sets on the market at any one time if eBay is anything to go by.

I guess each collector needs at least one, with some owning a few so they can have multiple sets working at one time displaying different things.

AdrianH 25th Sep 2020 9:48 pm

Re: Future Supplies of Standards Converters?.
 
I think there are a few DVI standards, some connectors I have are pure digital, some have analogue lines as well to enable me to convert with a simple plug to VGA, as I said I also use mini display port adaptor to drive my VGA connected monitor, so that must also have the analogue lines passed through unless it generates it's own?

What I do not know is if modelines will work with various PC ports such as HDMI, display port, etc, connectors.

I guess it will be a suck it and see. I am aiming to go from a VGA connector with a few resistors and a cap into a System A modulator, I have just build the adaptor. I have a few old laptops that have the VGA connector on them to start off with but it would be nice to get it to work with the nvidia cards in this PC.

Adrian

1100 man 25th Sep 2020 10:31 pm

Re: Future Supplies of Standards Converters?.
 
Hi Adrian,
This thread may be of interest to you if you have not already found it!


https://www.vintage-radio.net/forum/...d.php?t=144356

Various people have experimented with generating 405 using a PC with good success.

Cheers
Nick

AdrianH 25th Sep 2020 10:43 pm

Re: Future Supplies of Standards Converters?.
 
Thank you Nick, I will add that to my list, the problem I have is I use Ubuntu Linux here on my computers so I am trying to figure a few things can I do it in Linux and will my NVS 510 card support it?

I may have an older card somewhere but fining it is another matter.

I wish I under-stud more about PC's and their workings.

Adrian

FRANK.C 26th Sep 2020 9:49 am

Re: Future Supplies of Standards Converters?.
 
1 Attachment(s)
Quote:

Originally Posted by greg_simons (Post 1292799)
Hi frank
Yes, i would be delighted to relieve you of one of those boards, I'm definitely doing the thing.
Greg.

Hi Greg
I have checked and I have both Hedghog and Hedghog II PCB's.
Send me a PM and let me know which you want.


Photo below of both. The two on top are bottom/top of Hedghog and the two on the bottom are Hedghog II.


Frank

jjl 26th Sep 2020 10:37 am

Re: Future Supplies of Standards Converters?.
 
Quote:

Originally Posted by AdrianH (Post 1292834)
I think there are a few DVI standards, some connectors I have are pure digital, some have analogue lines as well to enable me to convert with a simple plug to VGA, as I said I also use mini display port adaptor to drive my VGA connected monitor, so that must also have the analogue lines passed through unless it generates it's own?

What I do not know is if modelines will work with various PC ports such as HDMI, display port, etc, connectors.

I guess it will be a suck it and see. I am aiming to go from a VGA connector with a few resistors and a cap into a System A modulator, I have just build the adaptor. I have a few old laptops that have the VGA connector on them to start off with but it would be nice to get it to work with the nvidia cards in this PC.

Adrian

There is no real reason for modelines not to work with digital video interfaces such as HDMI, DisplayPort and the digital part of DVI. The graphics card driver or electronics may restrict the allowable resolutions and timings though.
DisplayPort and Mini DisplayPort are purely digital interfaces as is HDMI - there are no analogue RGB and sync signals on these.
Note that DVI was deprecated several years ago and will eventually disappear. It seems that DisplayPort and its mini variant are becoming the video interface of choice on current production desktop and laptop PCs.

John

AdrianH 26th Sep 2020 10:53 am

Re: Future Supplies of Standards Converters?.
 
OK, I need to do more reading up on the subject and try to get it to sink in, I am trying to use a few adaptors to generate a 405 video line without success. The mini display port to VGA adaptor is giving me a composite video signal, but at a frame rate of 60 Hz so the mode lines are not working with the Radeon HD 7470 card it does not appear to support it.

I will not post more in this thread as it seems to be off topic to the original post, perhaps I will start another thread.

Thank you.

Adrian


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