Friday, April 8, 2011

Adding to a attic antenna farm.....

A new addition to the family click to enlarge all photos
Well the snow has finally cleared and the warm weather seems to just be on the horizon by the weekend it is supposed to be 20C. To celibate the warm weather I felt it was time to do some attic antenna additions. A few posts ago I compared the attic dipoles against the vertical outdoor Sidekick. The results were not in favor of the Sidekick at all. It got me to thinking that it was far better to have just all attic antennas. I avoid having to put up and take down the Sidekick outdoors. Also the "condo cops" will no longer be a worry with no more outdoor
excavated radials
antenna. I had always wanted to try the MFJ-1788 antenna it seemed like the way to go. I placed my order with the local ham dealer and then I began to think........."What about trying the Sidekick up in the attic???" I emailed the company and they told me that many customers had tried this and were successful. I also placed a posting on the High Sierra user group site. There I go mixed reactions but most were in a positive direction. It was during this brain storming the local dealer called me and said the antenna was special order and did I still want it......Ahhh I thought a way out of the order. I told them to hold off and that I was going to give the Sidekick option a go. First order of business was
repaired radial
to get the 16 ground radials out of the ground if I could. We have had a nice thaw of the snow and it has been raining for some days now so the ground would be soft. To my surprise the radials came out very nice there was just one that broke and I had to add a short piece to it and then heat shrink was added. I mounted the antenna in the attic and placed the 16 radials best I could in a circle around the antenna I crossed my fingers and gave the antenna a go....I only tried 3 bands 15,20 and 40 but to my delete the SWR was 1.2!!!!!! Now tomorrow I have to permanently   run the coax today the coax just went from the radio room and up the hatch way into the attic.  There is one question I would like to ask my readers and it is this.......As you can see from the pictures the radials are just laid down over the attic floor (insulation) I am at max going to
Radials on the floor
be running 5 watts do I have to have the radials raised off the attic floor. I understand there can be voltage in these wires but also there is electrical cables up there as well with voltages as high as 240 volts. You comments on this would be greatly appreciated.

4 comments:

  1. Personally I would use insulated wire for radials. You can get high voltages at the ends. Whether the voltage would be high enough at 5W to be a fire risk I wouldn't like to say, but I'd insulate the ends as well to be on the safe side.

    I'd try to keep the radials away from mains wiring to avoid coupling noise into the antenna (and RF into the mains.) But I presume you've had a listen already and know if it seems noisy. I'm looking forward to reading about how this works out.

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  2. Hi Julian, I have used regular insulated wire and the ends have heat shrink on them as well I hope this is good enough. Or I will have to raise them up off the floor. As for keeping the radials away from house wiring I have tried to do that but it was hard. I will give it a good listen on Saturday and see if I have any RFI issues in the house as well. I will be over the weekend trying it on WSPR compared to the dipoles that are up there.

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  3. Hello Mike, it's always nice to have free space in the attic. My attic is in use by my daughter. We made a sleeping room of the attic. I like the MFJ-1788, but it's too expensive for my limited budget. ;-) I agree with Julian about the radials. I am curious about your results with the new antenna. 73 Paul

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  4. Good morning Paul, yes I have come up with an idea to make sure the hot ends of the radials is looked after so all in the attic is safe. I will be posting my solution as well later this weekend results of how the Sidekick does in the attic.

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