UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Television Standards Converters, Modulators etc

Notices

Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions.

Reply
 
Thread Tools
Old 7th Jun 2020, 8:55 pm   #1
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default My 819 line French TV project

Dear fellow vintage TV enthusiasts,

Last year I was able to get my hands on a couple of TV sets that support the French 819 Line standard, so naturally I wanted to generate some signals for those sets. Among the sets I have are a Sony TV9-90UM the French version of the TV 9-90UB and a Radiola (Built by Philips) TV originally built for the Belgian market. This latter set is in mint condition and the CRT is like new.

I ruled out using an up-conversion from 625, because I wanted to get an idea about the true resolution of this vintage HD format. So the best approach in my mind was to use a PC to generate the required signals from 720p and 1080p footage.

Luckily I had come across Kat Mantons threads regarding this subject matter which helped me a lot in getting my project up and running. I would like to thank Kat for sharing this information regarding the mode lines for 819, this is much appreciated!

Modern Linux systems can be made to generate odd resolutions very easily nowadays. Here are the steps I took to get my Linux Mint system running on an HP 8440p laptop computer to output 738i i.e. the French 819 line system.:

Step #1) First we need to find out the internal designation of the VGA port. In order to do that we need to open the console and input this command:

xrandr | grep -e " connected [^(]" | sed -e "s/\([A-Z0-9]\+\) connected.*/\1/"

This will yield some output like:

LVDS1
VGA-0

Hint: You can copy the above by using the usual "control+c" keys. In the console you need, however, to use "Shift+Control+v" to paste.

The first is the internal LCD panel of my laptop, the second (VGA-0) is the VGA port. Please take note that the VGA port will only show up in the list if something like a monitor or adapter is connected to it. Here "VGA-0" is just an example, depending on the PC system used this may have other numbers.

Step #2) Now we need to generate the new resolution using Kat Mantons mode line. We key in this command in the console:

xrandr --newmode "819_TV" 29.3203 1152 1168 1240 1432 738 744 745 819 -hsync -vsync interlace

and make it known to the VGA port by using this command:

xrandr --addmode VGA-0 819_TV

As can be seen we use the internal designation of the VGA port "VGA-0" obtained in step #1 for this second command. If everything went well the VGA output should now have an 819 line signal at its output. This will show up as a second monitor to the right of the current display. In order to play a video through the VGA port simply drag the the player window to the "monitor" on the right and put it in full screen mode. I usually use VLC and set its aspect ratio to 2,21:1 to get the correct format of 16:9 footage on a 4:3 screen.

Please take note that the new resolution is not permanent and will have to be re-configured after a re-boot. In order to make this change permanent the easiest way is to edit a file named ".profile" that can be found i the home folder. Just add the two lines from step two at the bottom of the file.

Hint for the Linux novice: Please take note that this is a hidden file and you will only be able to see it if you hit Control+h on the keyboard. Any file or directory in Linux that begins with a "." will be hidden.

In order to obtain a good quality 1Vpp video signal from the VGA port of my PC I built a circuit that will entirely run off the 5V supplied by the VGA port on pin #9. The circuit itself runs on 3,3V and provides 2 outputs with 1Vpp into a 75Ω load. Since not all PCs and graphics adapters provide a 5V output powerful enough to run the circuit which needs around 16mA I have made provisions for an extra power input via a micro USB port. A blue LED lights up if the supplied voltage is high enough to power the circuit i.e. above 4.2V.

I use the THS7314 video amplifier to drive the outputs and amplify the signal to the required 1Vpp. A simple matrix generates the luminance signal from the red, green and blue signals. The H and V sync signals are fed into an XOR gate to turn them into a form of composite sync. This is not fully system compliant but my TVs work very well with this signal. In order for this to work with only a single 74HC1G86 XOR gate the vertical sync from the VGA port has to be inverted. This can be achieved by simply changing the mode line at the end. instead of having "-vsync" there it should be changed to "+vsync" that's it. Here is the complete mode line:

"819_TV" 29.3203 1152 1168 1240 1432 738 744 745 819 -hsync +vsync interlace

Here is the circuit diagram and a few images of the board I have designed in KiCAD. It mostly uses SMD components.

Click image for larger version

Name:	VGA2CV-Rev01.jpg
Views:	150
Size:	39.3 KB
ID:	207978

Click image for larger version

Name:	Modeline_VGA2CV_Board1.jpg
Views:	142
Size:	28.6 KB
ID:	207979

Click image for larger version

Name:	Modeline_VGA2CV_Board2.jpg
Views:	166
Size:	73.4 KB
ID:	207980

The project data for this board is available in KiCAD format. Please send me a PM or mail and I will send it to you.

In order to get the signal onto an RF carrier I used a modified version of my system A modulator that I had introduced here in the past. This uses only one crystal to generate the vision carrier and a simple LC circuit for generating the difference frequency between vision and sound carriers which in this case is 11,15Mc. I was able to use an original FM IF filter for the oscillator that generates the 11,15Mc intermediate carrier. This intermediate carrier is then mixed with the vision carrier signal and depending on the French channel to be generated the difference or sum frequency needs to be filtered out giving the sound carrier. The sound carrier generated by this method then goes to an AM modulator that is fed with the audio signal. I shall be posting the final circuit of my system A modulator with the French modification here in an upcoming post.

Click image for larger version

Name:	819 - Modulator-Final-2.jpg
Views:	133
Size:	41.0 KB
ID:	207982

I was lucky to find a 56,57Mc crystal in my junk box which is close enough to the French channel F3 at 56,15Mc. Since channel F3 is an odd numbered channel the sound carrier in this case is above the vision carrier by 11,15Mc i.e. at 67,30Mc or in my case due to the slightly off crystal at 67,72Mc. It is worth noting that even numbered channels have the sound carrier below the vision carrier in the French system, while odd numbered ones have it above the vision carrier. So I tuned the sound carrier filter in my modulator to 67,7Mc and was able to get sound and vision in glorious 819 lines on my TVs...

Click image for larger version

Name:	819-TV-Pic2.jpg
Views:	293
Size:	91.8 KB
ID:	207981

To be continued...
Semir_DE is offline   Reply With Quote
Old 7th Jun 2020, 10:39 pm   #2
Richard_FM
Octode
 
Richard_FM's Avatar
 
Join Date: Sep 2017
Location: Stockport, Cheshire, UK.
Posts: 1,337
Default Re: My 819 line French TV project

Sounds interesting, I've seen two 819 line sets at different times running off an 819 line Aurora, both of which were producing a very sharp & clear picture.
__________________
Hello IT: Have you Tried Turning It Off & On Again?
Richard_FM is online now   Reply With Quote
Old 8th Jun 2020, 6:46 am   #3
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 532
Default Re: My 819 line French TV project

Hi Semir,

Good results!

I recently restored my Philips TF651A 819 line set.
Pictures, see below.

Jac
Attached Thumbnails
Click image for larger version

Name:	2020-02-07 TF651 268 TC RTF schuin klein.jpg
Views:	254
Size:	50.3 KB
ID:	207993   Click image for larger version

Name:	2020-02-07 TF651 276 beeld Apollo 11.jpg
Views:	242
Size:	83.8 KB
ID:	207994  
Jac is online now   Reply With Quote
Old 8th Jun 2020, 8:23 am   #4
FRANK.C
Heptode
 
FRANK.C's Avatar
 
Join Date: Feb 2006
Location: Roscommon, Ireland
Posts: 627
Default Re: My 819 line French TV project

Hi Semir
Great results. 819 lines looks really good.

Frank
__________________
FRANK.C is offline   Reply With Quote
Old 8th Jun 2020, 9:04 am   #5
FRANK.C
Heptode
 
FRANK.C's Avatar
 
Join Date: Feb 2006
Location: Roscommon, Ireland
Posts: 627
Default Re: My 819 line French TV project

Hi again Semir
Just wondering how the THS7314 video amplifier preforms with 819 lines.
Does it's 8.5 MHz low pass filter have any noticeable effect on the video? I suspect not.

Frank
__________________
FRANK.C is offline   Reply With Quote
Old 8th Jun 2020, 11:08 am   #6
Richard_FM
Octode
 
Richard_FM's Avatar
 
Join Date: Sep 2017
Location: Stockport, Cheshire, UK.
Posts: 1,337
Default Re: My 819 line French TV project

Here are the two I've seen at events, the first is the Radiola on the left, and the next year I managed to get a close-up of the Philips.
Attached Thumbnails
Click image for larger version

Name:	49948038801_8de1098870_c.jpg
Views:	207
Size:	96.3 KB
ID:	208006   Click image for larger version

Name:	49948332592_ae5dc57088_c.jpg
Views:	250
Size:	100.5 KB
ID:	208007  
__________________
Hello IT: Have you Tried Turning It Off & On Again?
Richard_FM is online now   Reply With Quote
Old 8th Jun 2020, 7:13 pm   #7
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Quote:
Originally Posted by FRANK.C View Post
Hi again Semir
Just wondering how the THS7314 video amplifier preforms with 819 lines.
Does it's 8.5 MHz low pass filter have any noticeable effect on the video? I suspect not.

Frank
Hi Frank,

Before using the THS7314 I had built a simple adder network to get the luminance signal. I can not see any difference between this solution and the simple one. Since my TVs are of later build their IF bandwidth is limited at around 6Mc which poses the real bottleneck in the signal chain. So no the THS 7314 works fine in this application. The only effect I could see was in the H-sync this had some ringing which I had not noticed in the simple solution. I added the 1kΩ/33pF LPF to reduce high frequency content in the sync and then it passed through the THS7314 without exhibiting the ringing.

I do have a friend with an older French TV that may have the full 10Mc bandwidth. When he gets it repaired I will check it out. I do need to get some test cards though to be able to better judge the resolution.

Cheers

Semir
Semir_DE is offline   Reply With Quote
Old 8th Jun 2020, 9:33 pm   #8
rambo1152
Nonode
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 2,282
Default Re: My 819 line French TV project

Hi Semir,

This post documents my "Eureka" moment when I got Kat's idea to work with a Windows PC, simply by using a compatible graphics card and Jeroni Paul's "WinModelines"
I use it for 405 lines, Peter Scott uses it for his pre war 405/240 line set.

I use this modulator
and this very simple interface,Click image for larger version

Name:	interface.jpg
Views:	108
Size:	41.9 KB
ID:	208059 as described by Jeroni Paul.

Here's the system in action.

https://youtu.be/ahzdx4KgWBg
__________________
--
Graham.
G3ZVT

Last edited by rambo1152; 8th Jun 2020 at 9:46 pm.
rambo1152 is online now   Reply With Quote
Old 8th Jun 2020, 10:15 pm   #9
peter_scott
Nonode
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 2,543
Default Re: My 819 line French TV project

I had a similar problem with the simple XOR of the H and V syncs on 405 lines and built a crude monostable arrangement to get a truer pulse stream.

Peter
peter_scott is online now   Reply With Quote
Old 9th Jun 2020, 10:01 am   #10
peter_scott
Nonode
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 2,543
Default Re: My 819 line French TV project

I don't have an 819 line set but looking back I see that I used a different modeline to you not as high resolution but on VHF 405 my Sony 9-90 couldn't deal with higher bandwidth signals:

Modeline "600x778_25 20.5kHz 50.0Hz" 15.070 600 608 683 736 778 786 800 819 interlace -hsync -vsync

but could only display it on 405 lines.

Peter
Attached Thumbnails
Click image for larger version

Name:	IMG_20181223_094855 (Medium).jpg
Views:	176
Size:	65.8 KB
ID:	208087  

Last edited by peter_scott; 9th Jun 2020 at 10:08 am.
peter_scott is online now   Reply With Quote
Old 9th Jun 2020, 4:54 pm   #11
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Quote:
Originally Posted by rambo1152 View Post

and this very simple interface,Attachment 208059 as described by Jeroni Paul.
Hi Graham,

this is the circuit I used initially before making the more sophisticated one. I had also come across the site with all the mode line info a few years ago but had this project on the back burner. Now that I am on the German version of Furlough (Kurzarbeit) thanks to corona I have some extra free time to work on many neglected projects...

Thanks for posting the video, your TV looks great! which reminds me that I still have to finish restoring my Bush TV62...
Semir_DE is offline   Reply With Quote
Old 9th Jun 2020, 5:12 pm   #12
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Quote:
Originally Posted by peter_scott View Post
I don't have an 819 line set but looking back I see that I used a different modeline to you not as high resolution but on VHF 405 my Sony 9-90 couldn't deal with higher bandwidth signals

Peter
Hi Peter, That is interesting that the 9-90UB can display the 819 signals in the way you show. Well the H frequency of 819 is roughly twice that of the 405 signal so I guess it syncs on every second H-pulse...

I have also thought about using some additional logic to get more compliant V pulses, but my TVs so far are quite happy with the current offering of XORed pulse trains. The French V-sync is basically very simple on odd fields it's just a single 20s pulse starting from where the H-sync would've started. In the even field the 20s V-sync starts halfway through the line and ends just before the next H-Sync. Since the TVs are happy I will leave things as they are for now, however.
Semir_DE is offline   Reply With Quote
Old 9th Jun 2020, 7:29 pm   #13
peter_scott
Nonode
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 2,543
Default Re: My 819 line French TV project

Hi Semir,

I hadn't looked at the 819 line waveform before. As you say it's very simple and I understand now why you are staying with the XOR.

Thanks,

Peter
peter_scott is online now   Reply With Quote
Old 9th Jun 2020, 7:46 pm   #14
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Hi Peter,

here is the spec for the original waveform of the French system:

Click image for larger version

Name:	Sync-Aufbau.jpg
Views:	117
Size:	44.0 KB
ID:	208135

Click image for larger version

Name:	Sync-Daten.jpg
Views:	83
Size:	91.5 KB
ID:	208136

I think it is quite surprising that the 20s pulses are sufficient for v-sync...

Since the granularity of the mode line configuration for vertical timings is one full line, the PC generated sync which is a full line of 49s in each field is more than twice as long as the original one, but it works...
Semir_DE is offline   Reply With Quote
Old 9th Jun 2020, 9:02 pm   #15
peter_scott
Nonode
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 2,543
Default Re: My 819 line French TV project

Thanks Semir, I've copied the two docs to my standards conversion file. Your screen picture sync looks good.

Peter
peter_scott is online now   Reply With Quote
Old 10th Jun 2020, 12:54 am   #16
Karen O
Rest in Peace
 
Join Date: Jul 2011
Location: Bridgnorth, Shropshire, UK.
Posts: 787
Default Re: My 819 line French TV project

A very impressive accomplishment!

Maximum respect!
Karen O is offline   Reply With Quote
Old 11th Jun 2020, 11:02 pm   #17
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Dear all,

here is an update of this project. After mulling over the modulator design I decided to build both the VGA to composite video converter and the A/V modulator onto a single PCB. The design is SMD-based an will fit in an aluminium box roughly the size of a cigarette pack. Power options will be either USB or VGA, although I believe the latter will not work on most PCs. Here is the circuit diagram some values might still change slightly when I build the circuit:

Click image for larger version

Name:	VGA2RF1-R1.jpg
Views:	99
Size:	79.2 KB
ID:	208294

I have included a low pass filter at the output in order to prevent hamonics from spilling into Band III where I have all my 625 channels. Band I will be used for exotic signals such as this one.

I have found a company that still offers to make custom crystals in small quantities, at 30 each not a cheap option though. I have ordered two vision and two sound carrier crystals each for the French F3 Channel i.e. 56.15Mc vision, and 67.3Mc sound. They are scheduled to arrive in early July.

Today I finished the first revision of the PCB. This will work as a single layer, but I will use a double layer one where the top layer will be reserved for ground. Since this is an RF circuit it is always a good idea to have a large ground plane:

Click image for larger version

Name:	PCB-819-VGA-R1.jpg
Views:	101
Size:	89.0 KB
ID:	208295

Weather permitting i.e. if it rains over the weekend I will assemble a prototype and post results here.

Cheers

Semir
Semir_DE is offline   Reply With Quote
Old 13th Jun 2020, 7:23 am   #18
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 532
Default Re: My 819 line French TV project

Impressive work Semir!

I have a very high resolution (ORTF) 819 line test card. Just send me a pm with your email address.

Jac
Jac is online now   Reply With Quote
Old 13th Jun 2020, 11:15 am   #19
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Quote:
Originally Posted by Jac View Post
Impressive work Semir!

I have a very high resolution (ORTF) 819 line test card. Just send me a pm with your email address.

Jac
Hi Jac,

Thank you very much for offering the test card, that was exactly what I was looking for as an authentic add-on to this project! PM is on its way
Semir_DE is offline   Reply With Quote
Old 13th Jun 2020, 11:38 am   #20
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 54
Default Re: My 819 line French TV project

Hi again,

yesterday, or rather early this morning I assembled the first unit. Since I am still waiting for the crystals I had ordered last week, I tried it with what I had at hand 65.53Mc and 76.64Mc which is not really a French channel but the vision carrier is close enough. Sound is above not below vision but I tried anyway and it worked on my Sony TV9-90UM. Here are some images of the assembled unit:

Click image for larger version

Name:	Combo-mod_top.jpg
Views:	96
Size:	59.9 KB
ID:	208381

Click image for larger version

Name:	Combo-mod_bottom.jpg
Views:	95
Size:	84.6 KB
ID:	208382

Click image for larger version

Name:	Combo-mod_w_case.jpg
Views:	84
Size:	45.0 KB
ID:	208383

Once the crystals arrive I will finish the project. probably in early July. The difficult part will be to make a nice looking cut out for the VGA connector in the back of the aluminium case. I have a friend with a laser cutting machine though and I am planning to ask his help...

I will also test this with 405 once I get the mode line working on a PC here. I have crystals for channel A1 so that should not pose a problem. If anyone here is interested in the KiCAD design data I can send it by mail. Just send me a message.

Cheers

Semir
Semir_DE is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 11:45 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Copyright ©2002 - 2020, Paul Stenning.