[Mitch]

OK, I've been planning on trying to mod my 4 port for a while, so that I don't have to use the custom switchbox. Today I finally tried it and was successful. It turned out to be fairly simple and the only problem was that Atari made a late change to the 2 port power circuit that wasn't included in the schematic. I didn't notice this at first, but after a quick trip to the local electronics store for a diode, I was able to complete the mod.
I celebrated by playing a few games of Koffi and Final Legacy.

If anyone is interested in doing the mod, I could probably write up a quick description.

Mitch
http://atari7800.atari.org

[Inky]

Please do!

[Rob Mitchell]

Mitch said:

If anyone is interested in doing the mod, I could probably write up a quick description.

Yes .. please .. Now that I'm thinking of getting into the 5200 .. (after ignoring it for several years) I think I'll do this and a Video Audio out mod too!

Rob Mitchell, Atlanta, GA

[Cafeman]

Please do it Mitch. It can be difficult to find the 4-port RF's.

[King Atari]

Nice job, Mitch, this will be useful to a lot of people.

[Mitch]

OK, I'll try to get something written up this week.

Mitch
http://atari7800.atari.org

[jsoper]

Hey Mitch, I modified a 4 port myself. Is this similiar to your fix?

1. Modifiy 5200 for S-video (RF no longer needed)
2. Remove RF/power cable
3. Add power jack to console, connect to ground and to high current inductor
3. Connect other end of inductor to where the RF/power cable was.
John

[Mitch]

jsoper said:

Hey Mitch, I modified a 4 port myself.  Is this similiar to your fix?

1.  Modifiy 5200 for S-video (RF no longer needed)
2.  Remove RF/power cable
3. Add power jack to console, connect to ground and to high current inductor
3.  Connect other end of inductor to where the RF/power cable was.
John

No, it's a little different. I didn't modify it for S-Video (though I may when I have more time), so it still has the RF cable. Except that it is only carrying RF now, no power through it. I'll write up a description of the mod soon.

Mitch
http://atari7800.atari.org

[MrRetroGamer]

jsoper said:

Hey Mitch, I modified a 4 port myself.  Is this similiar to your fix?

1.  Modifiy 5200 for S-video (RF no longer needed)
John

Can this be done on a 2 port as well? How do you do this???

[Mitch]

Atari 5200 4 port power mod

Parts needed:
Power jack 2.5 I.D. 5.5 O.D. (I think)
47uf Electrolytic capacitor 35v
.1uf Ceramic capacitor 50v (usually marked 104)
1N5391G Diode (NTE 5800)
Four inchs of medium gauge wire (probably around 18 gauge)

When I went to get the power jack, I took the 5200 power supply with me and tried the different size jacks until I found one that fit properly. Unfortunatly, I forgot to note down what size it was. :-( I believe the above is correct, though.
The diode may be a little hard to track down so I have include the NTE equivalent. Which, incidentally, is what I ended up using.

First you're going to need to remove a couple of components from the board. They are: LB, a 2.7uH inducter located between the modulator and soldered in RF cable; and C45, a 4700uf electrolytic capacitor located just above the RF plug in socket.

Next, install the 47uf electrolytic capacitor in C45 where you removed the other capacitor. Make sure to note polarity.
There should be two holes for positive at C45, install one end of the diode at the positve hole you didn't use for the capacitor. I would recommend installing the diode on the bottom of the board. Make sure that the end with the band (cathode end) is soldered in at C45. Attach the wire to the other end of the diode.

Now comes the tricky part, you need to install the power jack. I chose to install it in the same spot as the power jack on the 2 port. So, that is what I'll describe here. You will notice that there is a capacitor (C40) that is slightly in the way. You need to install the jack so it is directly in front of the capacitor. Bend up the positive lead on the power jack. Now drill two holes for the negative leads. If you positioned it right, one of the holes should be going through the large ground trace on the top of the board. Solder the the lead, going through the ground trace, to the trace. If you scrape a small portion of the green covering off of the trace, it will be easier to solder. Don't scrape away the trace, though.
On the bottom of the board jumper the two negative leads together. Solder one end of the ceramic capacitor to the two negative leads you just jumpered.
Notice that there is a handy hole in the corner of the board next to where you have installed the power jack. Feed the the other end of the ceramic capacitor and the other end of the wire through the hole. Bend the power jack's positive lead toward the hole. Solder the wire and ceramic capacitor's lead to the positive lead on the power jack.

You are now finished. Take a minute and examine your work to make sure nothing is touching that shouldn't be and that all the connections are solid. Remember this is the main power circuit and you don't want to fry your 5200!

Now for the standard disclaimer. You do this mod at your own risk. No warranties offered. It worked for me and if you do it correctly, it should work for you. But if you fry your 5200 don't blame me.

If you have any questions, you can either post them or email me. I'll try to answer it if I can.

Mitch
http://atari7800.atari.org

[Mitch]

MrRetroGamer said:

jsoper said:

Hey Mitch, I modified a 4 port myself.  Is this similiar to your fix?

1.  Modifiy 5200 for S-video (RF no longer needed)
John

Can this be done on a 2 port as well? How do you do this???

It should work fine on either model.
The instructions are in the 5200 FAQ.

Mitch
http://atari7800.atari.org

[salkatt]

hi all,
londoner in UK here, a/v comp mod-ed my 4 port system, want to use the remove rf switchbox mod, but dont know wot an inductor is??????
told need a 2amp high voltage inductor, but we dont have a componant called that in UK.???
wot else is it known as, and wot does it do??????

[JB]

Mitch said:

jsoper said:

Hey Mitch, I modified a 4 port myself.  Is this similiar to your fix?

1.  Modifiy 5200 for S-video (RF no longer needed)
2.  Remove RF/power cable
3. Add power jack to console, connect to ground and to high current inductor
3.  Connect other end of inductor to where the RF/power cable was.
John

No, it's a little different. I didn't modify it for S-Video (though I may when I have more time), so it still has the RF cable. Except that it is only carrying RF now, no power through it. I'll write up a description of the mod soon.

Does that affect the image quality?

[Allan]

Mitch, on Thu Dec 12, 2002 12:47 AM, said:

First you're going to need to remove a couple of components from the board. They are: LB, a 2.7uH inducter located between the modulator and  soldered in RF cable; and C45, a 4700uf electrolytic capacitor located just above the RF plug in socket.

I have a 4-port 5200 that was modded years ago to allow the use of the 2600 adapter. One of the wires is connected to the lower eighth pin on the cart port and the front part of LB 2.7uH inducter that you are suppose to remove for the 4-port power mod. What am I suppose to do with this wire? Any suggections?

Allan

[Mitch]

Solder the wire into the hole that's left when you remove that leg of inductor LB. (actually L8, stupid typo on my original post)

Mitch

[sine25]

if i just want to make a switch box, i need the video cable from that box to a regualr RF atari box right, (from the one listed in FAQ)? anyone make these boxes could give me a hand?

[HP Atari King of Michigan]

If I get a 4-port 5200, I am looking into getting this mod done! I currently have a 2-port.

[¿°¿]

I got a question. Does the power coming in go ONLY to the voltage regulators? I want to run mine off a 12 battery because I don't have a power adapter [if it does, then it can handle the 12.5 volts from the battery.] Or does it have to have an adapter that puts out AC power?

[JB]

It takes DC in. And the voltage fluctuates a fair bit among power supplies. 12.5 isn't a problem.

[Bryan]

This might help too:

http://www.atariage....l?SystemID=5200

-Bry

[¿°¿]

Jeez! I could build my own atari out of spare parts using the diagrams! And yes, that helps. Thanks!