UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Television Standards Converters, Modulators etc (https://www.vintage-radio.net/forum/forumdisplay.php?f=95)
-   -   DVD on 405 tv without converter? (https://www.vintage-radio.net/forum/showthread.php?t=137376)

12jslater 12th Jun 2017 10:42 pm

DVD on 405 tv without converter?
 
Is it at all possible to input a DVD player in a 405 line television without using a standards converter?

Thanks, Jake

chriswood1900 12th Jun 2017 11:39 pm

Re: DVD on 405 tv without converter?
 
Jake
Unfortunately not, without a standards converter and modulator the 405 tv has no way to be able to understand the output from the DVD which will be 625 line and with negative modulation (black and white will be reversed). The signal also needs changing to VHF aerial input as very few old TVs could just take a video signal.
Chris
Also see this
https://www.vintage-radio.net/forum/...ad.php?t=79988

Dave Moll 13th Jun 2017 8:07 am

Re: DVD on 405 tv without converter?
 
Even at baseband video, as presented by a SCART (or whatever) connection, there's no way it's going to make sense of the 625-line signal.

Although I have never tried it myself, with earlier VHS machines it was apparently possible to record and play back 405-line content owing to the way they recorded a full field (or was it frame?) in a single stripe (diagonally) across the tape, but I understand that later machines tried to be more clever by introducing processes specific to 625-line that messed up this quirk. As far as I know, there is no similar loophole with recording to DVD.

peter_scott 13th Jun 2017 11:32 am

Re: DVD on 405 tv without converter?
 
If you can copy the DVD content so that you can play it using VLC player and you have a suitable graphics card and a modulator for applying the signal via your TV aerial socket then the answer is yes.

See: http://www.vintage-radio.net/forum/s...d.php?t=136670

Peter

Restoration73 14th Jun 2017 4:43 am

Re: DVD on 405 tv without converter?
 
Also you should note that although your DVD player and new TV may play Region 1 disks (NTSC 525 line) most 625 to 405 standards converters cannot function with them.

peter_scott 14th Jun 2017 12:16 pm

Re: DVD on 405 tv without converter?
 
Quote:

Originally Posted by peter_scott (Post 951797)
If you can copy the DVD content so that you can play it using VLC player and you have a suitable graphics card and a modulator for applying the signal via your TV aerial socket then the answer is yes.

See: http://www.vintage-radio.net/forum/s...d.php?t=136670

Peter

I see that VLC Player does actually play DVDs directly.

Peter

12jslater 14th Jun 2017 7:04 pm

Re: DVD on 405 tv without converter?
 
Thanks for all the responses. I have been wanting a television as a project instead of the usual radios, however I wanted to get an older set (pre 1955) just due to the external look, however I may have to look for an older 625 set.

kan_turk 14th Jun 2017 7:29 pm

Re: DVD on 405 tv without converter?
 
At the risk of being burned at the stake - many older 405 line sets can be persuaded to run at 625 lines - did it myself in the early 60s

Rgds to all
John

Focus Diode 14th Jun 2017 7:33 pm

Re: DVD on 405 tv without converter?
 
I now have, again, a DVD recorder which accepts everything, even blank tape. I have a few 405-line VHS tapes from the '90s which could do with 625-line transfers. The only known reliable way is optical conversion.

Video grabbers and the second LiteOn DVD player I have is useless for transferring less than mint condition VHS tapes, automatically going in to pause if there's a drop out and the likes. Not unexpectedly it refuses to recognise 405-line video.

Away from home at the moment so I'll give it a try with the new Sony DVD/HDD recorder. Seeing it records blank VHS tape It might handle 405 video, I don't know but it would have to be played back on a 405-line set and System A modulator.

I'll try it and will report back in due course.

12jslater 14th Jun 2017 7:52 pm

Re: DVD on 405 tv without converter?
 
Persuaded is a strong word, and how?

kan_turk 14th Jun 2017 8:46 pm

Re: DVD on 405 tv without converter?
 
Line timbase was often happy at 15KHz even before changing tuning cap - Bush TV 53 comes to mind - parallel IFs as per 405 practice works fine - reverse vision detector and replace sound det with ratio det - although slope detection works after a fashion - didn't use intercarrier sound and was only interested in VHF (being in Ireland) so no need for UHF tuner - this sound arrangement was common in early US sets

Rgds
John

SteveCG 15th Jun 2017 3:19 pm

Re: DVD on 405 tv without converter?
 
John, to follow on from what you said:

... and also allowed US vision IF pass-bands to be narrowed to help extreme fringe area reception for monochrome TV without affecting the sound reception. You can't really do that dodge with intercarrier sound TVs.

Nuvistor 15th Jun 2017 8:13 pm

Re: DVD on 405 tv without converter?
 
You can, perhaps not as much as with separate channels but you can get away with some. I think it was about 0.75Mhz to a 1Mhz, couldn't do it with colour TV though. If you went to extreme there was always a risk of instability as well as poor sound.

Some of the community aerials in the council flats gave very poor signals.

Frank

Studio263 16th Jun 2017 8:40 pm

Re: DVD on 405 tv without converter?
 
Don't be tight, buy an Aurora converter and stop messing about. For a few hundred pounds all these problems will disappear. Even allowing for this, TV restoration has to be the cheapest hobby that's actually worth doing; this sort of money goes nowhere with old cars (etc) I can assure you.

Hammer / piggybank time...

peter_scott 16th Jun 2017 10:04 pm

Re: DVD on 405 tv without converter?
 
You can buy a graphics card and splitter cable for less than £15 and once you've got those all you need is a modulator. There are plenty of simple modulator circuits around.

Peter

Nuvistor 17th Jun 2017 7:50 am

Re: DVD on 405 tv without converter?
 
Quote:

Originally Posted by Studio263 (Post 952681)
Don't be tight, buy an Aurora converter and stop messing about.

Hammer / piggybank time...

See post 3 , possible reason for keeping costs down.
http://www.vintage-radio.net/forum/s...d.php?t=137422

Frank

peter_scott 17th Jun 2017 11:38 am

Re: DVD on 405 tv without converter?
 
Check-out the latest posting here:
http://www.vintage-radio.net/forum/s...804#post952804

Peter

Focus Diode 17th Jun 2017 6:09 pm

Re: DVD on 405 tv without converter?
 
I'm currently transferring one of my 405-line VHS recordings I did back in 1993. The flat TV thing in the living room gives the expected display, plus the frame slowly drifts downwards. The Sony HDD/DVD recorder seems happy to record what's on the tape. The true test of course will be playing the finalised DVD copy back on a 405-line set via a System A modulator.

space_charged 18th Jun 2017 8:46 pm

Re: DVD on 405 tv without converter?
 
Yes indeed kan_turk (John), a 405 lines TV can be persuaded to run at 625. I too did this with my trusty Philips 17TG106U when I was in sixth form at school back in the early 70s. I had a working UHF IF strip and I connected it to the Philips with a multi-way switch so I could use the set on 405 or 625. The vision detector had to be reversed for 625. It worked really nicely and I used it for several years. The IF strip had a ratio detector (UABC80) and I just fed that into the Philips via my system switch. The sound was a big improvement over what was on offer from 405!

Charles

Oliver35 25th Jun 2017 11:33 pm

Re: DVD on 405 tv without converter?
 
This thread here is excellent- https://www.vintage-radio.net/forum/...d.php?t=130716
I think other threads suggested above link to it too. The OP also has a great video on YouTube showing it working. It's injecting direct video into the video output valve rather than generating an RF signal, but if you're purist you could build a modulator. I've only got one 405 tv, and I'm going to try this approach, once a few other projects are out of the way. One tv doesn't justify (for me) a £200 outlay on an Aurora, superb though they doubtless are. I'd not restored a TV before, and bought a little Ferguson for £25 locally, which turned out to be a straightforward (ish) and very rewarding project. https://www.vintage-radio.net/forum/...d.php?t=134196
Go for it, I say!

Oliver


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