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My temporary random-wire antenna and 9:1 unun have already been taken out of service. Cheer up though - they are out of service because I was so pleased with how they were working, I decided to make a more permanent version!
I built my permanent version of the 9:1 unun into a 4" x 4" exterior enclosure. As for construction techniques there was very little difference in the method I used for this one, compared to what I did for my smaller, portable version. The most obvious difference was the weatherproof box, and the addition of a large eye bolt in the "top" of the box. Other than these obvious difference, there were a couple other things that I did with this one:
- All hardware is stainless steel
- Every piece of hardware that penetrates the box was mounted with rubber washers to help seal out the weather.
- I used a dab of silicone as "glue" to help hold the torroid in place
So just like that I had a new, more rugged, weatherproof 9:1 unun. This meant that it was time to make another trip to the roof. The way our addition was built, when standing on the kitchen roof, you are at the gable end of the of the house, behind the garage. This gave me a fairly easy place to mount the unun at the end of the eve.
This spot works out very well, because it is easy to feed the unun from the temporary shack in the master bedroom closet, and when I eventually finish the basement shack, I'll be able to drop a run of coax straight down the corner of the house, to the entrance panel for the shack.
The pictures tell you pretty much everything you need to know, but I'll give some of the highlights of the mounting on the house end. The box was mounted using exterior screws. I put a small dollop of silicon at each spot I was going to be running a screw in, to help seal out the weather. The large eye bolt became the mounting point for the "house end" of the antenna. I used a heavy duty screen-door spring and a couple of carabiners between the eye bolt and the fence insulator holding the end of the antenna. I also left enough of a service-loop between the insulator and the unun so that the spring could stretch fully. For the counterpoise side, I ran a solid 14 gauge wire from the unun down to the metal roof below.
The "house-end" of my random wire antenna. To answer the question - no my house isn't that much bigger than my neighbors. Our house just happens to sit on the crest of a little hill so our neighbors on both sides are slightly lower in elevation.
Now I'm sure there are some "bigger is better" folks out there who might ask why I didn't use heavier hardware, use a lag screw into the house instead of the eye bolt in the box, etc. My choice in hardware was actually very deliberate. I chose sizes that would hold everything firmly, but would also be the weak-point in the event of any type of failure. With this arrangement, should the worst happen, the plastic box or one of the connectors should break and let everything drop, instead of pulling parts off my house!
At the other end, I also replaced the mason's line that was temporarily holding the antenna in the tree. My first step was to use the mason's line that was in place to haul up a proper rope. Again, because the other end is attached to my house, I didn't use the heavy duty rope that many people usually use - I used a relatively lightweight 250 lb rope. I also ran an eye-screw into the tree at the back corner, about 10' off the ground. Since I have kiddos running around out back, I wanted the end to be up high enough that they couldn't reach it by standing on any of their toys, but low enough that I could reach it with a step ladder.
This was also another spot where I gave the antenna just a little bit of wiggle room. With the antenna at full height I put a loop in the rope about 2 feet from where the eye screw was. I then used a bungee between this loop and the eye screw.
If (when) the bungee eventually gives in to the outdoors, I also made a clove-hitch with the end of the rope so that if (when) the bungee snaps, the antenna will only drop a couple of feet. I might eventually put a screen-door spring at this end too, but for now, this will work just fine!
So there it is - same wire in the air, but more robustly installed, since I've decided to keep it around for a while!
One last thing before I go - please sign up for my mailing list so you can be among the first to know when I've written a new post! I appreciate everyone that reads my blog regularly, so I'd like to return the favor by giving you the first shot at everything new that gets posted!
Bye for now!
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