MAKING THE CABLE
These instructions are for a 12awg per polarity cable. for the 13awg and 15awg versions, look below at the Modification section.
The cable capacitance is about 240pF/ft (bases on a 45.25ft run). To avoid amplifier oscillation, which is a bad thing, keep your cable runs to less than 20ft. Some amplifiers can handle a higher load, but I am not sure what ones. This is a warning from Chris VH's website. If you need a longer run, try the 13awg version. I will get those numbers up as soon as I can
First you need to set up your gear. I find it best to work outside on my lawn. The grass has little friction on the wire, you can put the rods into the dirt, and you have the ability to do long runs of cable. At one end of the yard, stick the rods into the ground about a foot or so and spaced at 6" apart. then you will want to secure the wire into the drill chuck.
For the wire, you will need 4 lengths of cat5 that are approximately 15-20% longer than the cable you want to make. Take one length and remove the jacket. Then you will need to separate the twisted pairs. I find that with longer runs, it is easy to use the drill to start to untwist the wires and then secure 3 of the 4 pairs to a rod and walk the 4th out of the group of wires. If you have to pull hard, then you are doing something wrong.
Now attach the twisted pairs to the rod (a little masking tape and looping the wire around the rod secures the wire nicely) such that they are evenly spaced in a square at the same distance as the rod spacing. At the loose end of the pairs, thread the wire through a hole each of the respective holes in the jig. You need to keep each pair separated and not crossed. Then one at a time, wrap around the wires bolt on the jig. It is VERY important that all of the pairs are the same length. I do this by attaching one wire at a time while keeping tension on the wire and keeping the jig square.
Now for the hardest part. Will keeping some tension on all the wires, you are going to use the drill to twist all 4 sets of twisted pairs in the direction OPPOSITE the direction that the pairs are twisted (i.e.. if the pairs are twisted clockwise, then the drill goes counter-clockwise. It is crucial that when twisting, that the wires keep their uniformity. Here is what I mean. If you are to take a cross section at any two points on the 4 pair cable, that all the 4 pairs are in the same order. To do this, you will have to start the drill out slowly. Continue twisting till 14 turns per foot (that is one of the pairs). The cable will shrink a little as it is twisted. When you think you have enough twists, keep tension on the cable, hold onto the jig with one hand and remove the jig from the drill with the other. There will be some tortional tension in the cable, so let it unwind by holding the bolt in your hand with enough tension to let it untwist. Then remove the cable from the rods and jig. Repeat this 3 more times so that in the end you have 4 larger twisted sets each containing 4 twisted pairs.
Below is an example of what a completed cable should look like. The top is if you make the small twists with a single color set. The middle is when the small twists has one of each color. The bottom is what one of the small twists should look like. Notice that the twist is in the opposite direction.
When you have all 4 wire sets, then you are going to twist those all together just as you did in the previous steps. When you twist it, you will do it in the OPPOSITE direction of the previous set (i.e. if the pairs are twisted clockwise, then then small set of wires is counter-clockwise, and this final cable is again clockwise). You will do this till the cable is at 10 turns per foot. Below are two examples. The top has each small twist set coming from a length of cat5, and the bottom has the colors separated from 4 runs before any twisting.
Below is an example of what a completed cable should look like. The top is if you make the small twists with a single color set. The middle is when the small twists has one of each color. The bottom is what one of the small twists should look like. Notice that the twist is in the opposite direction.
After the cable is completed, cut to length and terminate like you would with the Chris VH.That is:
Untwist the ends about 4 inches
Separate beige from the colors (or stripped from un-stripped--depends on your cat5)
Strip each wire back about 3/4 inch
Re-twist the wires back keeping the beige as one polarity and the colors as the other.
Cut of the extra copper and terminate as to your liking
Your ends should looks something like this:
Modifying the Cable
With these number, you can modify the instructions to make 13awg and 15awg versions.
13awg: for the 12awg, you make 4 small wire sets that each contained 4 twisted pairs. For the 13 awg, use 3 twisted pairs. This should be twisted to about 16twists/ft. The final cable should be at 13-14 twists/ft
15awg: for the 12awg, you make 4 small wire sets that each contained 4 twisted pairs. For the 15 awg, use 2 twisted pairs. This should be twisted to about 18twists/ft. The final cable should be at 14-16 twists/ft
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