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THE RCA STUDIO II SWITCHBOX
& HOW TO BUILD ONE YOURSELF
by Mike Pelletier

The RCA Studio II game has a unique 'Switch Box'. This Switch Box is an input/output device that allows to connection to:
1. The TV
2. Game Console
3. Power Supply.

The Switch Box has not been built since the late 1970's. There is no easy way to buy a Switch Box off the shelf due to its unique characteristics.

Here is a picture of the Switch Box. Note the TV hook up on the bottom side is for older style TV sets. A simple $2 coax cable 'balun' can be used to plug into a modern TV coax on the back of your TV set. The power supply input in on the face (looking at you) and the game console input in on the left hand side. On the top of the Switch Box, you can see a little black lever poking out. This is a switch that allows one to go from TV to Game mode without having to unhook all the connections.

I have seen many RCA Studio 2 games bought and sold without the Switch Box. They are a fairly rare find to buy on various internet sites. I had to buy mine for $30 in early 2002. What I did find out once I bought mine and took it apart is that one can build their own pseudo Switch Box with some basic electrical components.

Based on the importance of the RCA Studio II Switch Box to the operation of the system, we need to explore how it actually works.

The internal components of the Switch Box are made up of simple capacitors, inductors (coils), Input/output terminals and a switch. These items can be obtained from a local Radio Shack or electronics hobby store.

In making your own switch box, I made several attempts. The easiest way to build the box was to forget about the 'switch'. That is, when I want to use the RCA game, I just hook it up and when I am done, I un-hook it. The implementation of a switch just made the design more difficult with little improvement to using the game.

Using the schematic diagram: (pick 1977, RCA Studio 2, Schematic Switch Box) found at http://videogames.org/html/ and this parts list one can build their own:

C1 = 100 pf orange ‘disk’ with ‘101J’ Radio Shack # 272-1015 printed on it $1

C2 = C3 = 0.002 uF but I used 0.001uF Radio Shack catalog # 272-126 $1

C4 = 47 uF at 16 Volts Radio shack # 272-1015 $0.50

T1 = five leaded transformer with ‘Red Eye’ dot out of Radio Shack PK30 kit, Catalog # 273-1601 $2.69

RFC1 = RFC 2 = brown-two leaded coils in same package as above for T1

DC input Terminal = Coax Power Jacks 2.1. Radio Shack catalog # 274-1565 $2

DC Power Supply = input 120v (wall outlet) to 9V dc at 300mA (or you can use 250mA)female socket. $3.50

Phono Jack = (Console’s 18 ft cord into here ) Radio Shack catalog # 274-346 $2.99

Two copper wires= $0, go to input on TV. You may need a balun if Coax only on TV $2

Total component cost = $13 to $15

The system above DOES NOT use a ‘switch’ to easily go from TV to Video Game. If you want to play the game, you need to hook the above unit up to the power, TV and Console. When you are done playing, you need to unhook the unit. DON’T LEAVE THE UNIT HOOKED TO POWER UNATTENDED. I don’t know what could happen !

The home made Switch Box was made to be very simple. The componenets came from Radio Shack. As you can see in the picture, the 'holding cell' for all these parts soldered together was a $1 Tupperware plastic container. My hands could not fit in anything smaller.

For the input/output terminals for power, TV and consule, I simply melted the plastic on the side of the container with my soldering iron. Try to do this outside !

The toughest component to find was the 5 leaded balun, coil or transformer (whatever you want to call it), item listed as T1 on the schematic and parts list. I found it in a Radio Shack Coils/Transformers mixed bag of parts. I called it the 'red eye spider' since it has a red dot in the middle of the 3mmx3mmx2mm insulating material. I have no idea what the value of this thing is, but it seems to work great. Hard to see in the picture of the home made device, but it is right in the middle of the whole mess!

I also used the brown coils/transformers in the above Radio Shack mixed bag of parts as item RFC1 and 2. No idea of values, but they work. And, they are more numerous to find than the red eye spiders.

If you have any updates, questions, comments, complaints or whinings, please let me know.

Mike in NH
mikpel@hotmail.com

ps: thanks to Scott and Mark for helping me with the project




  
       
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