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Author Topic: Parts list for RGB mod  (Read 6385 times)
gertk
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« on: September 26, 2011, 08:23:23 PM »

I am compiling a list of parts needed for the adding the RGB output to a G7400 and want to make a package deal out of it: all the parts needed are in the bag, including a Scart to DIN8 cable

Rene, do you have a circuit diagram of the G7401 ? I am unsure about parts 711, 768, 770 and 816

So far I have come up with this list:


Resistor:
740 741 742  = 560 ohm (3 pieces)
743 744 745  = 1,5 kOhm (3 pieces)
769 772 764  = 1 kOhm (3 pieces)
773          = 47 ohm (1 piece)
765          = 330 ohm (1 piece)

IC:
683          = 7407 (1 piece)
683 (s)      =  14 pin socket (1 piece)

Diode:
701 702 703 704 685 686 687 = 1N4148 (7 pieces)

Transistor:
684 = BC547 (1 piece)

Misc.:
J4 = PCB socket DIN8 (1 piece)

cable DIN8 to SCART (1 piece)


At the Radio Onderdelen Markt at the Lichtmis I found 4 (used/desoldered) DIN8 PCB sockets which seem to fit onto the G7400 board, I have 2 new ones coming from RS USA hopefully the correct type and in time for Apeldoorn. With a bit of luck we can do a 'live'  RGB mod to RevivalStudios G7400 (or another G7400 just to be safe)
I also have a spare G7400 with a defunct EF9340/9341 which seem to function correct otherwise, it already has a new mains switch fitted.
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Rene_G7400
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« Reply #1 on: September 27, 2011, 01:18:50 AM »

Rene, do you have a circuit diagram of the G7401 ? I am unsure about parts 711, 768, 770 and 816

768 = 4k7
770 = 680 Ohm

711 and 816 are not used.

If you make an RGB mod like this, you will have only RGB, no composite video. With my RGB mod you will also have composite video (described here: http://www.the-nextlevel.com/odyssey2/articles/g7400guide/rgbmod.php ).
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gertk
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« Reply #2 on: September 27, 2011, 07:16:43 AM »

Thanks Rene,

The Composite video output can be a useful addition since many new TV sets only have CVBS scart inputs (because the sets being so thin that the onboard SCART socket is replaced by a super small socket with an adapter cable)
Then again when going for Composite video there is no need for putting in all the parts for RGB..

Another output I am contemplating on is an YUV output since that still is present on almost all new TV sets and also on a lot of older LCD's and plasma's.
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« Reply #3 on: September 27, 2011, 12:44:21 PM »

Another output I am contemplating on is an YUV output since that still is present on almost all new TV sets and also on a lot of older LCD's and plasma's.

I'm very interested for a YUV output too ! ...and the "PHILIPS' spatial sound" feature with the TDA3810 too !
« Last Edit: September 27, 2011, 12:52:57 PM by VideopacBelgium » Logged

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gertk
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« Reply #4 on: September 30, 2011, 07:28:17 PM »

I will take (only) two complete RGB kits to Apeldoorn, from the 4 sockets I aquired there were 2 of the 'Commodore' type (that is: thinner pins and the pins are not in a circle but in a horseshoe shape) They do fit on the G7400 board though.
The other sockets haven't arrived yet.  Sad I wil bring my already modified G7400 so maybe Revivalstudios can demonstrate on that and let me 'massacre' his G7400  Evil
A couple of mains switches are also 'in the bag'.
See you at Apeldoorn




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gertk
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« Reply #5 on: September 30, 2011, 09:09:38 PM »

Another output I am contemplating on is an YUV output since that still is present on almost all new TV sets and also on a lot of older LCD's and plasma's.

I'm very interested for a YUV output too ! ...and the "PHILIPS' spatial sound" feature with the TDA3810 too !

Wow, the TDA3810.. I have seen this once in an Elektuur/Elektor article about a small portable FM radio wich was based on a mono FM frontend and then this chip was used to make it pseudo-stereo.. Never understood why on earth you should do that when there were single chip stereo-decoders available...

For mono to pseudo stereo conversion this could be nice. Alas the chip was produced in 1985...

About the YUV output: you need some clever opamp trickery to create Y, R-Y and B-Y at the correct levels and include the intensity bit too. Also the Y output needs to carry the sync signals.
Too bad chips like the AD724/725 have no outputs for Y U V signals, that would be perfect. I have used them for RGB to PAL conversion in a PAL testimage generator based on a VGA card running at PAL frequencies.  
« Last Edit: August 07, 2013, 12:55:10 PM by gertk » Logged

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« Reply #6 on: October 21, 2011, 07:37:21 AM »

The RGB mod with the 'proper' DIN 8 PCB socket (supplied by RS components)
« Last Edit: August 19, 2012, 08:07:15 PM by gertk » Logged

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« Reply #7 on: March 20, 2012, 10:05:39 PM »

Just did the CVBS+RGB mod on a G7400 aquired from marktplaats and the result is great, it also became a new power switch.
The small screen runs in CVBS (yellow cinch plug only), the big screen in RGB
« Last Edit: August 07, 2013, 12:52:10 PM by gertk » Logged

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« Reply #8 on: March 20, 2012, 10:10:34 PM »

A pic of the resistor on the back of the G7400 PCB and the small screen video input (yellow plug) connected to a DIN5 to 4xCINCH adapter cable, unfortunately you can not get sound with this adapter cable.
« Last Edit: August 07, 2013, 12:53:08 PM by gertk » Logged

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