Homemade 405 line television. TV standards converter

[WIDLAKE]

I was lucky enough to see the BBC's experimental colour television at the Radio Show at Earls Court at the beginnings of the 60's. It looked good to me.

[MarkAJAgi]

UKTV History channel on 405 line VHF and I'm still waiting for Channel 5 to start.

[GW7ONS]

What an excellent piece of kit, have you published the design on a website yet, I would love to have a go at building one to go with my Alba T534 that I am restoring at the moment.

[Witheredgoogie]

Great job Emerald, I have not seen your design but in digital terms is it case of dividing 3 into 2 ? Your next task (should you decide to accept) is to get yourself a nice simple ? Philips G6 and make it produce 405 line NTSC colour LOL.

[emerald48]

@Witheredgoogie - Ha Ha many thanks. I don't think i'll be doing a colour version!!. You cant just divide 3 into 2 because you need to do something with the lost information. In simplest terms all 405 line S/C's drop approximately every third line and interpolate it's video into the other lines so no information is lost. I will do an article soon.

[michael68000]

emerald48 ,

I've just picked up an old Murphy set from a charity shop and (assuming the line output transformer is OK) I'm looking for a signal source. A PC is attractive as it doubles-up as DVD player, Freeview receiver and iPlayer.

I was wondering if you could bodge a 405 output from a graphics card with PowerStrip or other hack?

[emerald48]

Search for "foth tv" on Google. You'll find what you need.

[michael68000]

It looks a very useful website - many thanks

[northcliffe]

Well done! Wish I was up to making a 405 line converter. I have a working Bush TV22a I restrored. But I had to buy my converter to make it work.

[emerald48]

Which one did you buy?

[disremembrance]

It's a pity that a lot of the picture is missing round the edges due to a 405-line set seemingly being unable to do 'letterboxing'.

[emerald48]

Ha Ha!. I'm assuming you meant that as a joke :) - Just in case you were serious: The freeview box used as the 625 line source would letterbox the image anyway if it was 16:9 and you would see a letterboxed image on 405. As it happens, when this was done, UK History channel was broadcasting a 4:3 ratio image so nothing is lost and no letterboxing. The standards converter will convert to exactly the same image, letterboxed or not, - just to 405 lines instead of 625.

[spottydog4472]

Bah.......telly......it'll neva catch on!

Anyone seen my radio times lying around???

[thx1138X]

what would be extremely useful would be someone to make a 405 line video-mpeg tv card interface.

[emerald48]

It is already possible to output 405 line video from an existing SVGA graphics card using Linux. Then you can watch iPlayer in 405 !!.

[michael68000]

What card do you use?

[emerald48]

I don't use a card. My standards converter was designed and built from scratch using 74HC series IC's. There is no PC.

[schnirrschnirr]

The screen looks like a toilet seat.

[emerald48]

ha ha. Yes it does!

[405Hippy]

This is over a year old. Did it ever get anywhere?

[emerald48]

The unit was designed and built in 2004 and is still in regular use. There are minor improvements to be made but time and financial pressures have made this a low priority. The picture is pretty good. I made a good simple modulator design too. Maybe I will publish that on my website. I ought to put something on there !! :) M

[petermines]

Sterling job emerald48. I take my hat of to you.

I have a bush TV 32 in my workshop which I scrounged from the company I worked for many years ago.

I should try and find a way to get 1950's pictures back on to it.

My apprenticeship was all 405 band 1&3 and we had one CTV out in 1970.

I'm still in the trade today. What a headache.

[emerald48]

Thank you for your comments. It's true it wasn't easy but that's because I restricted myself to "off shelf" comonents and 74 seies IC's - just for laughs. Mainly because of Andrew Emersons 405 alive article which implied it couldn't be done!!. I still want my £50 from him :)

[tomsamja]

Do u know how to make a lcd or plasma tv???

[pchapman905]

@tomsamja They require specialized manufacturing and would be nearly impossible to build from scratch. You could theoretically build a CRT TV completely from scratch in your living room.

[thx1138X]

Good work, am working with 405 here also. great fun.

Cash Cow, yes like the 8-track tapes I released for my musician friend. Im rich also, sold 7 of them in 1 yr! Bahamas here also lol.

405 its the "future HD"

[emerald48]

Yes Trip1933 meant that as a joke!!!. One day though I may design something people actually need !!

[Tripp1993]

I think you should think about turning your designs into a CASH COW. You could make a fortune!

[emerald48]

Fortune!! Ha Ha !!. Many Thanks. You could be right... You know there must be at least 10 people worldwide wanting to watch 405 line TV, and with bulk orders like that I'd be sorted. Bahamas here we come ;)

[TeslaMaster]

Nice demonstration. Every information about your schematics and functioning is appreciated.

[emerald48]

I will be scanning my notes to a pdf soon.

[malc1961uk]

Looks good,

The BVWS has events where you could show your converter.

There are a few designs for 625 to 405 line converters and modulators around the web, have a look on the domino405 site for some info and links.

Malcolm

[ftipo]

great thing!! bravo!

[laurdy]

do you have the schematic available anywhere on the net or available for email?

[emerald48]

I posted this to evaluate interest. I wasn;t sure if anyone would be interested. I am going to provide the schematic and source code on a web page shortly. I designed this a while ago and I am collecting the information together to share. The design is not perfect and has a few cheats but provides surprisingly good and stable properly interpolated pictures.