What are these components (Atari STE schematics 'DL1' 'L403') ?

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tzok
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Re: What are these components (Atari STE schematics 'DL1' 'L403') ?

Post by tzok » Tue Jun 15, 2021 12:27 pm

The filter in the datasheet has the same topology and design frequency as one on the Atari schematics, so it has to introduce the same delay. Atari might have used parts from different vendors, but they had to keep the same parameters. The circuit actually will work without the delay line, and it is required only for Composite Video and RF out, so not much of practical use for today.

sporniket
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Re: What are these components (Atari STE schematics 'DL1' 'L403') ?

Post by sporniket » Tue Jun 15, 2021 9:20 pm

Good evening, and thank everyone for your inputs. I did not miss the references on the datasheet.

It turns out that the variable coil form factor and footprints was quite popular, if not standardized, and I could find converging data all around the web, Toko of course, and even Mitsumi (my best guess would be Mitsumi R-12 P526X like here ). So I will be able to confidently create a library for this L403.

I am not so lucky with the delay line. The best I could find from Mitsumi is a picture of a component with similar casing but bigger and only 3 pins, and not a single clue about a scanned catalog/datasheet that would give me some official data. So I will create a library based on my measurement, and for all intent and purpose it will be good enough
tzok wrote:
Tue Jun 15, 2021 12:27 pm
so not much of practical use for today.
Agreed, however my specific goal is "to convert the atari STE schematics into Kicad", so I have to also do the part that have no more practical use nowadays. I will happily ditch this part if I ever start a remake pcb, and I guess most of people would do the same.

And for the record, thanks to the remark from @czietz I could find the parts for the PAL version inside the service manual of the falcon :

Code: Select all

* L403 : 
    NTSC => part C100210 - variable coil 24uH 
    PAL  => part C100214 - variable coil 14uH
* DL1 :
    NTSC => part C100209 - Delay line 3.58MHz 
    PAL  => part C100213 - Delay line 4.43MHz

tzok
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Re: What are these components (Atari STE schematics 'DL1' 'L403') ?

Post by tzok » Wed Jun 16, 2021 10:07 am

So it seems, they have used a standard PAL/NTSC 1H (1 horizontal line) delay line (64/63,5us).
http://bpta.by/pdf/delay-line.pdf

sporniket
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Re: What are these components (Atari STE schematics 'DL1' 'L403') ?

Post by sporniket » Wed Jun 16, 2021 9:01 pm

tzok wrote:
Wed Jun 16, 2021 10:07 am
So it seems, they have used a standard PAL/NTSC 1H (1 horizontal line) delay line (64/63,5us).
http://bpta.by/pdf/delay-line.pdf
Thanks, now if you would have the same kind of document from mitsumi, that would be great. I searched for that too much time without results.

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