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Old 6th Feb 2023, 9:34 pm   #1
lloydwells
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Default Sony KV1320UB adjustment help.

For some time I've been recalling a kv1320ub now the problem I have is this cracking black and white picture cracking sound BUT I only get colour just at the very point it goes off tune now I'm assuming the offset for the colour carrier is just off Normally I only do B&W sets what specifically on the KV1320 would adjust the colour offset ?? As simply as humanly possible please.
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Old 6th Feb 2023, 11:52 pm   #2
simpsons
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Default Re: Sony KV1320UB adjustment help.

Hi Lloyd

I'm not sure what you mean by the colour offset as you will probably know that the colour information, in the European PAL system, is recovered from a local oscillator, generally crystal controlled, at 4.43 Mhz.

The only snag with your TV is that Sony, to get around the Telefunken PAL licence, designed a set which converted PAL to NTSC. Hence the Hue control.

This complicates matters which means that you do need the service manual to see what is what.

Experience with Sony Televisions of this age will show how good the components are and faults generally point to a dried up electrolytic. The issue will be which one.

What test gear do you have and how confident are you in following a schematic?

Chris
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Old 7th Feb 2023, 12:03 am   #3
lloydwells
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Default Re: Sony KV1320UB adjustment help.

Here in lies the problem I can cope with PAL this thing I've literally no idea what does what it's got umpteen small boards. What essentially happened was when bought it had a frame collapse it had bulging electrolytics all over the place so I got the schematic out and replaced THE LOT now I've got a cracking picture in B&W it'll only pick up the colour at the extreme ends of the tuned channel the colour has picture has a nasty cross hatch pattern to it now initially it did this when tuned to anything and the picture was distorted I twanged the AGC down a wee bit and that resolved the bendy pic so I'm where I'm at now but it just seems like it's not getting the colour Infor where it should be presumably that could be something to do with converting it to NTSC. Can I pump a video signal straight in to it somewhere to see if it's tuner related or after it I'm not entirely sure the AFT on it is working properly.
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Old 7th Feb 2023, 12:13 am   #4
Red to black
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Default Re: Sony KV1320UB adjustment help.

Have a look at this excellent sticky above this very section to see how this decoder works:
https://www.vintage-radio.net/forum/...d.php?t=136086
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Old 8th Feb 2023, 12:38 pm   #5
marceljack
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Default Re: Sony KV1320UB adjustment help.

Hi,
I think this problem has nothing to do with the "non PAL" colour decoder but most probably with a mistuning in the vision IF, which has the effect of attenuating too much the colour subcarrier when the UHF tuning is supposed to be correct.
If the level of the subcarrier falls below a certain level or if the frequency response around the subcarrier is very wrong, the "colour killer" prevents the colour decoder to work as a colour picture would be worse than in black and white in these conditions.
But realigning the vision IF requires equipment and some experrise, as well as service documentation explaining how to proceed.
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