[TowerTalk] Cable Runs

[Tod -ID]

Larry:

The really good ideas have already been expressed. I have a couple of things
that you might want to consider if your particular layout makes them sensible. I
have a 200 foot run from the house to the base of the HF tower. On the way I
make "stops" for other antenna locations. There are two bends in the run.

1. I hired an under-employed plumber to use his trencher to make a three foot
deep 18" wide trench. The cost was nominal and might be reduced if you rent one
and do it yourself. 

2. I used one 3" and one 4" white PVC conduit designed for carrying water [from
Home Depot] for the combination of hard lines [3 each 3/4" diam, 3 each 1/2"
diam] and control cables [2 rotator, 2 14-conductor cables] PLUS a separate
electrical conduit that carries 117 vac to each of the tower bases. I
deliberately separated the 117 vac to avoid potential problems. 

3. At each tower base GFI outlets are installed to provide convenient power.

4. At each bend I installed a large Rubbermaid box, 20 gallon or so. I cut holes
in the boxes for each size of conduit to enter at one end and exit at the other.
I used silicone adhesive to seal the box-conduit junctions. I built a frame
[using redwood or treated wood to avoid rotting] to keep the dirt away from the
top area of the box and then covered the frame with wood boards. Finally, I put
a large piece of flagstone over the top of each box. The location of the boxes
is easy to find and even though they are in the middle of my lawn my wife is not
troubled by them. The runs slope upward from the boxes so that water entering
the conduits flows to the boxes. I perforated the bottom of each box with
several holes to allow the water to seep into the ground below the box.

5. I inserted a length of 1/8" Dacron rope in each of the large conduits and
then tied the ends together. When I pull on one side the cord on the other side
moves too. The maximum length of a single run is 70 feet. I used the 1/8"
round-and-round cord to pull another line through one on the conduits. That new
line is used to pull additional control lines and CATV lines.

6. Since the length of each PVC section was 10 feet I had to assemble lengths
into the run lengths I needed. At the time I installed the conduits I inserted
the CATV hard line and control cables as I built the conduit. No pulling was
required. Naturally, after I started operating the system I found I wanted more
feed lines and control lines. That was when I was happy I had inserted the
round-and-round 1/8" cord when I built the conduit. 

7. Buy or borrow a Kellem grip and get a lot of lubricant when you pull
additional lines through the conduit. You will be happy that you made the lines
slippery and that you had something that really grip the end of the line
tightly.


I hope at least one of those ideas turns out to be useful for you.


73, Tod, K0TO