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ODYSSEY AV MOD

Started by VideopacBelgium, March 24, 2013, 12:25:35 AM

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VideopacBelgium

I would like to modify my Odyssey with AV mod.
Can somebody help me?
Thanks
Videopac digger

Seob

Help as in schematics or building it?
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VideopacBelgium

Videopac digger

Seob

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VideopacBelgium

Hugh !
I'm looking for the schematics to modify my ODYSSEY. (...not Odyssey²)
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Seob

Quote from: VideopacBelgium on March 24, 2013, 01:40:59 PM
Hugh !
I'm looking for the schematics to modify my ODYSSEY. (...not Odyssey²)

Ah, i already tough it was a little strange that you where asking for schematics of the O2.
8 bits of fun

Rene_G7400

Quote from: VideopacBelgium on March 24, 2013, 12:25:35 AM
I would like to modify my Odyssey with AV mod.

Since the Odyssey has no A, it will be a V mod only. :)
I've done that, but can't check right now how. Will let you know next weekend. I thought it was pretty simple. Probably just one transistor and a few resistors. Do you have the schematics of the Odyssey console?

gertk

#7
On this page: http://www.atariage.com/forums/topic/124552-odyssey-circuitry-diagram/ about three quarters down are some schematics.
Not sure if you can really find the complete video signal (My guess the signal is mixed on top of the RF carrier at the modulator test point 'Sweep input')
If you temporarily disable the RF carrier you could check the signal there with an oscilloscope.
>>G7000 G7200(P+S) G7400 N60 JET27 VG5000 ZX80 ZX81 ORIC-1 COMX35 Aquarius<<

VideopacBelgium

Right René, ...this is a V mod only  :)
I found the schematics here
http://www.pong-story.com/1tl200blak_sch.pdf
The J12 "SUMMER" module seems to mix the WALL, the BALL, the 2 PLAYERS, the V and H sync. to COMPOSITE VIDEO.
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Rene_G7400

Quote from: VideopacBelgium on March 25, 2013, 07:43:11 PM
The J12 "SUMMER" module seems to mix the WALL, the BALL, the 2 PLAYERS, the V and H sync. to COMPOSITE VIDEO.

Yes, it does. You'll need at least one transistor as an emitter-follower for a low output impedance. You might need a few resistors to adjust the levels.

Rene_G7400

Seems I haven't used any resistor. Just one transistor BC547. I've removed the RF oscillator and RF filter boards. (The two PCBs inside the metal boxes.) I've connected the base of the transistor to pin 10 of the summer board (J12), and the collector to the 6.2V power supply (for example pin 9 of the horizontal sync generator). The emitter of the transistor is the video output. If the input of your TV has a capacitor, you'll need to connect a resistor bewteen the emitter and ground. I've adjusted the frequencies of the Vsync and Hsync generators to get a 'PAL' signal.

VideopacBelgium

Thanks René, it works
However, the "background" in not black but gray.
I've used the "FILTER" PCB to fix the BC547.
The pin 3 to the base, the pin 7 to the emitter, the collector to the pin 4 of the RF oscillator connector just near (5,6 V)
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Rene_G7400

Quote from: VideopacBelgium on April 01, 2013, 01:04:15 AM
However, the "background" in not black but gray.

According to the manual, the background should be gray, not black (otherwise you won't see the graphics of the overlays).
http://www.magnavox-odyssey.com/Manual/US%20manual/6.jpg

VideopacBelgium

On some TV, the wall, the ball and the players are black instead of white!
I can turn them to white with a resistor 27 ohms between the video out and the GND.
Is this correct?
Videopac digger

Rene_G7400

Quote from: VideopacBelgium on April 04, 2013, 04:31:34 PM
On some TV, the wall, the ball and the players are black instead of white!
I can turn them to white with a resistor 27 ohms between the video out and the GND.
Is this correct?

27 Ohm is a bit low. Does it work with 82 Ohm too?