Thursday, April 14, 2011

Making attic radails safe......

radials with exposed ends
As you know from a recent post I moved the High Sierra Sidekick to the attic and one area that was still left undone was the antenna radials and making sure they were RF safe. Julian G4ILO brought to my attention the possible RF that could be at the end of the radials even with 5 watts. So over the weekend I was brain storming as to what to do to make the radials safe. To begin with the radials are insulated 14 gauge wire but at the ends there is some exposed wire and potentially a problem that I don't want to have. Some of the radials were just looped at the end and others had a plastic insulator that had to be removed. Some of the ideas I toyed
with
Radial loop end with high voltage tape
were raising the radials off the attic floor.That as I thought about it was going to be a real challenge and what if the RF hot radial made it's way back onto the attic floor...then what!! I am the type of person that has to mull ideas over before I come up with a workable solution. I came up with the idea of "over" insulating the radial ends better safe than sorry I always say. First I taped the wire looped ends with high voltage self amalgamating  tape. I purchased a 10 foot length of 3/4 inch PVC conduit and some plastic nuts and bolts. I then cut the conduit into 6
PVC pipe with  hole and sealed end
inch lengths, drilled a hole in each piece about 2 inches down from one end. Here is what I did, the radials loop was wrapped with high voltage tape self amalgamating tape. I then placed the loop end into the 6 inch PVC conduit and then I placed the plastic bolt into the conduit through the wire loop. I then added a nut to secure the bolt  this made sure the wire radial does not come out of the PVC conduit. The plastic nut and bolt was wrapped with high voltage tape and then electrical tape. Each end of the PVC conduit was sealed with high voltage tape as it is easy to stretch 
radial secured in PVC pipe

The finished product
and place over openings. This added project  allowed me to place the radials on the floor of the attic knowing the ends of the radials were well insulated. It was a bit of extra added work but well worth the time. I was able to bring each set of 4 radials down through that attic opening thus allowing me to work in the ends in the office below and not crawling around up in the attic. Above to the right is what the finished radial end insulating tube looked like. All ready to go up into the attic without the worry of RF at the ends of the ground radials making it's way were it shouldn't.  Just as a side note I did want to mention that when I am ever taping something with electrical tape I know it is tempting to just tear off the electrical tape when you are finished doing your wrapping of what ever you want to insulate. I always give a nice clean cut to the tape when ending the wrap. I find when you tear the tape it stress's the end and over the long run the tape begins to come off. This can possibly reveal the end you were trying to insulate. Then you are having to do the job over again.
Left side clean cut right side stressed


4 comments:

  1. Hi Mike, nice solution of isolating the radial ends. I use a lot of that rubber tape at my job and of course for the hobby. You're absolutely right, it does crimp over time and gets loose. You have to cut it nice and clean. How are the results with the Sidekick on your attic?? 73, Bas

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  2. Hi Mike, indeed a good looking solution. 73 Paul

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  3. Good evening Bas, yes I had thought about this for some time and hope this was the idea that would do the trick for some time to come.

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  4. Hi Paul, it seems simple but then as well does the job that I want it to do.

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