T-n-T wrote:
I was wondering if anyone could help me
with a design of a heat cable for my new terrarium.
I have on fairly expensive cable and would like to duplicate it.

Have you investigated simply purchasing another?

It has a 110v plug at one end and is about 8 feet long.
The end has a small knob which I assume is a resistor of some sort.

Perhaps a
http://groups.google.com/groups/sear...troller+heater

The actual heating part of the cable is about four feet long,
the rest is just to get to the outlet.

Does it look like it has a sensor?

BTW, i have seen some online for planted aquariums

Google has many facets:
http://froogle.google.com/froogle?sc...title:aquarium
http://froogle.google.com/froogle?sc...ntitle:Reptile