UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV 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.

Closed Thread
 
Thread Tools
Old 13th Jun 2020, 8:17 pm   #21
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
Default Re: My 819 line French TV project

No crystals or custom PCB in mine Semir I'm afraid.
The PVC tape join hides the RGB sync matrix!

Actually, drift of the 51.75 & 48.25 MHz "Holme Moss" free-running carriers is not a problem.
Attached Thumbnails
Click image for larger version

Name:	MODULATOR.jpg
Views:	218
Size:	119.5 KB
ID:	208416  
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 13th Jun 2020, 9:19 pm   #22
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

Gosh Graham, and I thought that my construction was bad!

Peter
Attached Thumbnails
Click image for larger version

Name:	P1050661a (Medium).jpg
Views:	199
Size:	102.8 KB
ID:	208417  
peter_scott is online now  
Old 13th Jun 2020, 10:32 pm   #23
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
Default Re: My 819 line French TV project

That's the problem when the initial proof-of-concept breadboard edition works so well, there is little impetus for improvement.

In my defence I did make a start on a slightly neater iteration over two years ago, but my only 405 line set has been poorly until recently, so I really should complete it now.

Click image for larger version

Name:	MODULATOR.jpg
Views:	181
Size:	118.7 KB
ID:	208427

I also need to write up grafting the LOPTX that David (FERNSEH) kindly sent me into the Cossor.

It's working fine; I just want to optimise the value of a tuning capacitor I found necessary, and mount the Tx in the original tin can.

Click image for larger version

Name:	DSCF0510.jpg
Views:	170
Size:	66.7 KB
ID:	208428
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 14th Jun 2020, 4:08 pm   #24
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 59
Default Re: My 819 line French TV project

Dear all,

here I would like to share some images of my TVs with the ORTF test card that Jac kindly sent to me.

Click image for larger version

Name:	Radiola_ORTF.jpg
Views:	331
Size:	97.7 KB
ID:	208458

This one needs some alignment, I know...

Click image for larger version

Name:	TV9-90_ORTF.jpg
Views:	303
Size:	74.0 KB
ID:	208459

In high resolution these images would show that the horizontal resolution of the TVs is limited to about 400 TVL while the vertical resolution is over 500 TVL. This is probably due to the fact that more recent 819 sets operated with a limited IF bandwidth e.g. the Radiola has roughly 6Mc and the small TV9-90 most likely even less. It would be interesting to see how the test card would look on an older French TV with the full IF bandwidth. On the other hand older sets may have worn out CRTs so resolution might be limited due to lack of focus in the CRT itself, but this is just an assumption on my side.

Cheers

Semir
Semir_DE is offline  
Old 14th Jun 2020, 5:00 pm   #25
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 640
Default Re: My 819 line French TV project

Hi Semir,

My Philips TF651A indeed displays a somewhat better definition.
The modulator I used is MC44BS373 based and thus has a limited bandwidth.

Nevertheless, with this the TF651A can display 650 lines horizontal (819 vertical).
To the naked eye it looks better than I managed to catch in a photo.

Click image for larger version

Name:	2020-02-07 TF651 266 TC RTF.jpg
Views:	285
Size:	85.9 KB
ID:	208460

Click image for larger version

Name:	2020-02-07 TF651 273 TC definitie detail.jpg
Views:	261
Size:	93.8 KB
ID:	208461

Due to influence from the magnetic field of the mains transformer, the picture wobbles a tiny bit, and this does not help for a sharp photo (and combine that with my very limited photographic capabilities )

Jac
Jac is offline  
Old 14th Jun 2020, 6:10 pm   #26
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

Are these resolution bars square wave or sine?

Peter
peter_scott is online now  
Old 14th Jun 2020, 6:35 pm   #27
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 640
Default Re: My 819 line French TV project

Hi Peter,

The bars are square waves, but since the higher harmonics (of the narrower bars) will not pass through the system, this might not make much difference?

Jac
Jac is offline  
Old 14th Jun 2020, 8:34 pm   #28
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

Hello Jac,

On your detail (second) picture if you look at the top where 350 is just truncated the lines look sharper than they do for the 350 in the centre left.

Peter
peter_scott is online now  
Old 14th Jun 2020, 8:43 pm   #29
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 640
Default Re: My 819 line French TV project

Hi Peter,

Yes they do. I think it has a lot to do with the contrast of the original:

Click image for larger version

Name:	part of RTF test pattern.jpg
Views:	190
Size:	50.5 KB
ID:	208477

I must try the set with a better test pattern (like I sent to Semir).

Jac
Jac is offline  
Old 14th Jun 2020, 9:05 pm   #30
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

Well that looks different but perhaps not in the screen shot with brightness reduced in the lower block.

Peter
Attached Thumbnails
Click image for larger version

Name:	819tc.jpg
Views:	157
Size:	31.3 KB
ID:	208478  
peter_scott is online now  
Old 15th Jun 2020, 6:29 pm   #31
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 640
Default Re: My 819 line French TV project

Hi Peter,

I had another go at photographing the test card on the Philips TF651A.
(Due to my inadequate photographic skills and the wobble in the picture, it looks a bit better to the naked eye though.)

Click image for larger version

Name:	2020-06-15 TF651 284 TC klein.jpg
Views:	219
Size:	81.6 KB
ID:	208545

Click image for larger version

Name:	2020-06-15 TF651 283 TC detail klein.jpg
Views:	169
Size:	38.0 KB
ID:	208546

Click image for larger version

Name:	TF651A detail test card.jpg
Views:	175
Size:	38.6 KB
ID:	208547

Jac
Jac is offline  
Old 15th Jun 2020, 7:39 pm   #32
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 59
Default Re: My 819 line French TV project

Hi Jac,

looks pretty good. Much better resolution than my Radiola TV. On your TV I'm sure you can probably read menus e.g. of VLC very clearly. That is a very nice vintage TV you have I just found this web site where yours is actually pictured.

My dream TV would be to get an E1 441 Line "Einheitsfernseher" but as only about 50 of them were ever built they are like gold dust and priced accordingly...

Cheers

Semir
Semir_DE is offline  
Old 15th Jun 2020, 7:56 pm   #33
Jac
Heptode
 
Jac's Avatar
 
Join Date: Jun 2006
Location: Eindhoven, Netherlands.
Posts: 640
Default Re: My 819 line French TV project

Hi Semir,

Thanks.
The set I hope to add to my small collection would be a (any) pre-war Philips.
I must confess that an E1 is also on my wish list, but no chance of ever finding one in this country.

Best regards,
Jac
Jac is offline  
Old 15th Jun 2020, 10:11 pm   #34
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

Hello Jac,

That does look good, especially in the close up.

Thanks,

Peter
Attached Thumbnails
Click image for larger version

Name:	P1020984 (Medium).jpg
Views:	149
Size:	45.6 KB
ID:	208581  

Last edited by peter_scott; 15th Jun 2020 at 10:41 pm.
peter_scott is online now  
Old 16th Jun 2020, 1:31 am   #35
red-duck
Triode
 
red-duck's Avatar
 
Join Date: Oct 2008
Location: Perth, Western Australia, Australia
Posts: 39
Default Re: My 819 line French TV project

I'm curious that the test card image is for ORTF 2.
Did the second channel ever transmit in 819 lines ? I thought it was 625 only.
I'd be interested in knowing the early history of ORTF 2.
__________________
Best Regards
Nigel
VK6CPU
Perth, Western Australia
red-duck is offline  
Old 16th Jun 2020, 9:40 am   #36
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

In my previous post I was trying to relate Jac's 819 line bandwidth to a 405 line benchmark. The lower half of the image shows a crop of the TRF test card displayed on a 405 line receiver that has 3MHz bandwidth. (The 3MHz grating on Test Card C equates to something like 425 lines on the RTF test card.)

Jac's 819 receiver has better resolution than the 405 line receiver and the active part of the 405 line is 80.8uS whereas the active part of the 819 line is 41uS so Jac's receiver has bandwidth greater than twice the 3MHz of the 405 line receiver. ~7MHz.

Peter
Attached Thumbnails
Click image for larger version

Name:	P1020984 (Medium)b.jpg
Views:	134
Size:	45.6 KB
ID:	208589  
peter_scott is online now  
Old 16th Jun 2020, 9:56 am   #37
Richard_FM
Octode
 
Richard_FM's Avatar
 
Join Date: Sep 2017
Location: Stockport, Cheshire, UK.
Posts: 1,999
Default Re: My 819 line French TV project

Quote:
Originally Posted by red-duck View Post
I'm curious that the test card image is for ORTF 2.
Did the second channel ever transmit in 819 lines ? I thought it was 625 only.
I'd be interested in knowing the early history of ORTF 2.
As far as I know it was 625 lines from the start, which I presume was system L without the SECAM encoding at first.
__________________
Hello IT: Have you Tried Turning It Off & On Again?
Richard_FM is offline  
Old 20th Jun 2020, 10:34 pm   #38
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 59
Default Re: My 819 line French TV project

Dear all,

I would like to share some more findings here regarding the implementation of an 819/576/405 signal generation system on a Linux PC in the hope some of you might find this useful. My first experiments were with two laptop computers an HP 8440p and an even older Dell Latitude 6400

Both employ the Intel integrated GMA graphics solution which seems to be limited when it comes to clock rates below 20Mc. While this is not a limitation for higher resolution output formats it will limit possibilities for outputting low res formats like PAL (576i) or 405i. Sine the french 819i format requires a clock close to 30Mc this format could be generated with ease on both laptop PCs. I was unable, however, to get a PAL or 405 output to work on those PCs.

Since I was aiming for a solution that could be switched to 405i, 576i and 819i I decided to conduct some more experiments. A few considerations had to be made for the whole system to work well with all desired formats:

1) The output of the TV signal should be over a VGA connector and this should be a second head on the PC. This meant a graphics card with both DVI/HDMI and ananlog VGA outputs needed to be found.

2) The main or primary monitor should have a decent resolution e.g. 1280x1024 or higher, so all OS menus, VLC player etc. could be run in a normal fashion

3) It should be easy to switch resolutions for the secondary monitor without a reboot and without interrupting playback of a video. This is to be able to demonstrate the different formats while playing the same video file.

4) The PC should be powerful enough to play HD content since only HD content could be down scaled to 819i while SD content would be up scaled thus not using the full potential of the 819i format. For a 405i only system a much less powerful PC would suffice as only SD content would need to be playable.

The problem, or so I thought, was to find a suitable graphics adapter that could be configured to output all desired formats while at the same time having an interface that was compatible with a modern PC motherboard. As I had read here that old GeForce 4 graphics cards were a suitable choice I tried an old GeForce 6600 with AGP interface. I still had this as well as the quite dated PC with a Pentium 4 processor. The results with the GeForce 6600 were disappointing. It worked with 405i but on 819i it produced a second vertical sync pulse halfway across the picture. Since the old Pentium 4 PC was not an ideal choice for playing HD content anyway I decided to investigate a more modern PC architecture.

I also had an old small PC that I had built a few years ago with an Asus N4L-VM Motherboard and an Intel core2duo this has a PCI-Express 16 interface which makes the choice of graphics card much easier. Also not the most recent technology but just powerful enough to play HD content as long as a good graphics adapter was used.

Originally this had an ATi Radeon 4000 (EAH4350) in it which worked well under Windows 8 as an HTPC. When I installed Linux Mint XFCE 32 Bit on this machine it also worked well for the OS and I could get modelines to work for 405i. It would not work with 819i, however, in this case the sync of every second field was inverted and no matter which setting I chose in the modeline this issue remained. Back to the drawing board...

As a next test I extracted an Nvidia N210 card made by MSI from another machine I had and put it into the one I was testing. This was the answer! All modes were supported immediately and I could switch between formats even while playing a video in full screen on the second "monitor" i.e. VGA output to my modulator. All this worked until I decided as suggested by the Linux OS driver manager to install the proprietary Nvidia drivers. After doing so the modelines no longer worked, so be warned only use the integrated Xorg drivers...

As a third choice I had ordered or more recent Nvidia N710 card made by Zotac. This costs around €35 and is very sleek and does not need a noisy fan. This card also works perfectly with all modes. Here is an image of the card which can still be bought online:

Click image for larger version

Name:	zotac-1.jpg
Views:	144
Size:	75.1 KB
ID:	209075

Click image for larger version

Name:	zotac-2.jpg
Views:	159
Size:	77.4 KB
ID:	209076

So as a conclusion from this non representative test it seems that Nvidia cards even of newer design work with all modes we need for generating 405i, 576i and 819i. Summary:

Intel integrated graphics: good for 819i not good for 405i (576i was not tested)
ATi Radeon EAH4350 (Radeon 4000 series): good for 405i, not Good for 819i (576i was not tested)
Nvidia N210 made by MSI: good for all modes 405i, 576i and 819i
Nvidia N710 made by Zotac: good for all modes 405i, 576i and 819i

Here are a few images of the settings:

Click image for larger version

Name:	405i-setting.jpg
Views:	161
Size:	54.7 KB
ID:	209077
for a 405i output

Click image for larger version

Name:	819i-setting.jpg
Views:	145
Size:	44.5 KB
ID:	209078
for a 819i output



A few hints for setting up VLC:

- I used the detached video interface setting, so the window containing the play list will remain on the PC screen while only the full screen video can be moved to the secondary monitor. This will allow adding new clips to the play list while playback is ongoing

- It is a good idea to select a fixed video output renderer instead of "auto" in the VLC video settings. If this is not done the VLC interface will initialize every time it starts playing a clip and this will move the full screen video back to the PC screen.

Finally an image of the PC in its case:

Click image for larger version

Name:	PC-case.jpg
Views:	159
Size:	83.2 KB
ID:	209079

I hope this information will be useful to others here while experimenting with modeline signal generation.

Cheers

Semir
Semir_DE is offline  
Old 21st Jun 2020, 6:33 pm   #39
peter_scott
Dekatron
 
peter_scott's Avatar
 
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
Default Re: My 819 line French TV project

I'm using an ATI Radeon HD 2400 and the fan is rather noisy so it's interesting that the Nvidia N710 works well without a fan. I thought there was some incompatibility between Nvidia cards and Jeroni Paul's Modeline program?

Peter
peter_scott is online now  
Old 22nd Jun 2020, 9:27 pm   #40
Semir_DE
Tetrode
 
Semir_DE's Avatar
 
Join Date: Jan 2019
Location: Heusenstamm, (Near Frankfurt am Main), Germany.
Posts: 59
Default Re: My 819 line French TV project

Hi Peter,

I did not use the "Winmodelines" program as such, just the posted modelines and the ones made by Kat Manton. These worked without any issues. I also use Linux not Windows, so the incompatibility described on Jeroni Pauls page plays no role.

I'll post the modelines I used here later when I'm on my other pc...
Semir_DE is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 10:49 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 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.