CTV Sony KV1820E color issues

Posted by: @cathovisor

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Pity I was banned from there

Hi Mike, nothing to stop you contacting the UKVRRR team and gently reminding them about the IP on these EPROMS. I feel if you did so calmly, they would more than likely stamp on that member's request.

https://www.vintage-radio.net/forum/sendmessage.php

p.s.

As I mentioned to you in the week, I've found no end of my website content plastered all over FaceBook, with no reference to the source. People these days assume everything is theirs for the taking.

I backed up the Pineapple EPROMS but would only release them to proven existing owners as detailed here.

Well, I don't know if they'll get the message as when I include the URL, I get a message saying "invalid redirect URL" I'll try again without this time.

Edit - boy, that was a pain in the proverbial! If you include the URL the message sending fails - it took THREE attempts to get it sent.

I see that UKVRRR has seen reason and locked the thread with a note about copyright after intervention by myself and others. Amusingly. Mr. Grant said he was going to send them a photographic image of the 27C801 EPROMs used in the generator... 🤣 

• @nuvistor thanks again for the link! I downloaded the .iso and burned it to a DVD, but my player is not cooperating. The older one with an analog output won’t read it, the BlueRay one only opens the menu and won’t let me select any test cards. Any idea what I could do about that? 
  In good news, I made some progress on my test pattern generator, so hopefully I‘ll have that working soon.
• The menu of a different DVD shows only traces of color, but is extremely clear and sharp. I‘m sure I‘ll get this thing working properly at some point…

@gschwab I can only tell you what I did. Tonight I download the file and burned the ISO to a DVD-R using the software that is in the Finder application on a 13 year old Mac Book Pro. I then played it in a 20 year old Sony DVD player to a 18 year old Sony 32 inch LCD TV, the connection was via SCART. I don’t know if the player has a RF output, never looked.

The DVD played fine and I was able to select various Test cards including Test card F, colour  bars, Crosshatch, grey scale among others. 

It will be Wednesday before I can check if the DVD player has a RF output, if it has and I can find a connecting lead I will try that but from what I have tested  it’s an excellent piece of work from Mikey405 on the UKVRRR forum.

It was a good test of my TV, Freeview box and DVD, they have been unpowered for about a month, I watch little TV at home.

@gschwab I managed to check the DVD player this morning, there isn’t a RF out put so I can’t test any further.

@nuvistor thank you so much for checking! I think the issue is definitely not with the .iso, but either with my burner or the player. I have an old Mac at home, will try that! Would really be great to have a DVD like the.

@nuvistor I tried again, but no luck. I used a DVD-R, seems like my player doesn’t like that. It plays fine on my PC. Will buy a different DVD and try again. Parts for the pattern generator should arrive soon, so hopefully I will make some progress this weekend

@nuvistor well, I got a different type of blank DVD, burned the image using my ancient Mac (only worked after taking the drive apart and cleaning the lens), but my DVD player still won’t cooperate. The DVD plays fine on all computers I tried it on, but my ancient player won’t accept it. I guess I will have to look around for another player.
I definitely know why I like old, analog technology better, non of those stupid compatibility issues…

Thanks again for all the help!

@gschwab Did you make sure the DVD was closed after writing, some DVD players won’t work unless the DVD is closed?

@nuvistor I did a bit of research, from what I understand, the OS version I have automatically finalizes/closes the DVD after burning. I think it might be time for a new DVD player, the one I have is really old and was given to me for free forever ago.

Progress again! I found a DVD player that will play the burned DVD. Thanks again for the link!

While the colors are still way off, the signals look better with this setup (DVD player and modulator) 

The b/w image and signal also look better, what do you guys think?

I will have to go through all the adjustments in the color signal path again, let’s see what happens. Definitely appears that the old Sony doesn’t like the signal from my HDMI converter.

After performing all the adjustment steps according to the manual, the picture is much better when using the DVD. However, I am still not 100% happy, I‘m sure the TV could perform better yet.

As I have written before, the best tuner setting for b/w reception does not coincide with optimal color. Any ideas what else I could check? It definitely seems like the TV is very sensitive to the source.

@gschwab The picture looks like the contrast is turned down and colour up. It appears that the luminance signal is weak, or it could be just the photo.

@nuvistor it‘s really mostly the picture. If someone can tell me how to take somewhat decent pics of a crt image, I would be really happy. The upper half of below shows the situation a little better.

The main issue is that colors are not displayed correctly. The red in the color bar at the top edges of the screen has a bit of a magenta tint. The colors do change with the tuner setting a bit, I almost feel like the transmission curve of the tuner might be causing this.

Well, I thought I had this settled, but I was totally wrong. Using a DVD player and a modulator, I was able to get a pretty decent picture. The main issue was resolved by twiddling around with some of the filters in the color amp and detector (not described in the manual). Before this, the color signal for two consecutive lines varied greatly, the phase seems to have been way off.

After all these adjustments were completed, I switched from the DVD player to the VCR-HDMI to Scart-Receiver combo. The image was awful, all colors were wrong. The menus of the VCR, that are supposed to be blue, were completely without color.

It really seems like th TV needs a complete readjustment of all filters, especially in the IF, which is not described in the manual. It seems super sensitive to any changes. What do the experts on here think, any ideas how to go about this without detiled instructions?

Is this one of those Sony's with the simple PAL decoder, like the KV 1330's? I have loads of trouble with those and things like HDMI-AV converters, and my Sumvision SD card player, yet they are fine with DVD or freeview. I came to the conclusion that they just don't like something about the signal from these modern devices, you can set up the decoder on one source, such as the media player box, but then it won't work with anything else! TV's with proper decoders seem to be able to tolerate less than perfect PAL signals.

@lloyd it does have a proper decoder, so no simple PAL. Still, extremely sensitive! Maybe I need to find a way to to display the color bar signal via HDMI and can then switch over to a regular HDMI signal. Or I will finally get a Raspberry…

I have a feeling that it’s a bandwidth issue, if anything is just slightly out of spec, the signal doesn’t go through completely. If I didn’t want to use the TV semi regularly, I would just leave it set up for the DVD player…

@gschwab 

If you suspect RF/IF alignment problems then it could be aggravated by many modulators being double sideband not vetisgial. Only cure is a full alignment with a sweep generator, not many of those available these days unfortunately.

You can use a modern spectrum analyser to do TV IF alignment. Just feed the tracking output into the tuner test point, pick up the signal at the detector and it's all laid out before you, no fiddling with marker generators and stuff.

I'm about to do this on a mid 60's Astor portable that's had its adjacent channel and sound traps mangled. Fortunately I have a full set of alignment instructions, nicely documented. Grandkids Christmas presents get priority though!

I have a Rigol DSA832E on loan from work. I'll have to learn to drive it first. A bit different to the Marconi I used to own.

It will be the first project in my new workshop. No more working on the dining room table!