make a cable descrambler

phreakabit's Avatar
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$12 Decoder Plans

Materials Required:

1 - Radio Shack mini-box (Part #270-235)
1 - 1/4 watt resistor, 2.2k-2.4k ohm (Part #271-1325)
1 - 75pf-100pf variable capacitor (Very hard to find: Special order)
2 - F61a chassis-type coaxial connectors (Part #278-212)
12" - No. 12 solid copper wire
12" - RG59 coaxial cable


1. Bare a length of No. 12 gauge solid copper wire and twist around a 3/8" nail or rod to form a coil of 9 turns. Elongate coil to a length of 1 1/2" inches and form right angle bends on each end.

2. Solder the variable capacitor to the coil. It doesn't matter where you solder it, it still does the same job. The best place for it is in the center with the adjustment screw facing upward.

Note: When it comes time to place coil in box, the coil must be insulated from grounding. This can be done by crazy- gluing a piece of rubber to the bottom of the box, and securing the coil to it.

3. Tap coil at points 2 1/2 turns from ends of coil and solder to coaxial chassis connectors, bringing tap leads through holes in chassis box. Use as little wire as possible.

4. Solder resistor to center of coil and ground other end of resistor to chassis box, using solder lug and small screw.

Diagram: Your circuit and design should look something like this:

5. Drill a 1/2" diameter hold in mini- box cover to permit adjustment of the variable capacitor from the outside. Inspect the device for defects in workmanship and place cover on mini- box. Tighten securely.

6. Place device in line with existing cable on either side of the converter box and connect to television set with the short piece of RG59 coaxial cable. Set television set to HBO channel.

7. Using a plastic screwdriver (non- metallic), adjust the variable capacitor until picture tunes in. Sit back, relax, and enjoy!!!

Due to different scrambling systems, you might find it necessary to change the range and values of the variable capacitor. I've also added a wiring diagram to help you with designing the circuit.
evileye's Avatar, Join Date: Jan 2007
xbsmntxhippyx's Avatar, Join Date: May 2007
Newbie Member
can someone who has done this post/email a picture of it to me? instructions are kind of vague.

JUST5_0's Avatar, Join Date: Aug 2009
Newbie Member
Can any one please send me this diagram! And does this really work?