Refurbishing and Erecting a 20 Element Two meter Beam
By Robert Pattison
Recently I acquired a 20 element beam for 144 MHz. It belonged to a neighbor, W2EIU and was in need of some tender loving care. This Cushcraft beam has 10 vertical elements and 10 horizontal elements so it afforded me an opportunity to do some weak signal work (CW & SSB) on two meters as well as possibly working some distant repeaters. This project meant I would have to obtain a rotator for the antenna and I would need to rethink my Diamond 2/440 Vertical and my 4 element 220 MHz beam’s location.
The first step was to inspect the antenna. It was determined that the nuts and bolts holding the elements to the boom were in desperate need of replacement. A trip to Lowe’s for stainless steel hardware did the trick. K8RVR and I set about the task of removing the old hardware and replacing it with the new and shortly thereafter the task was completed.
It was decided to remove the Diamond 2/440 from the chimney for relocation (another project). The 220 beam, if practical would be mounted above the new two meter beam. Mast sections were located from the boneyard stockpile and a tripod was set up in the back yard. I have found from experience that it is useful to set up and test antennas and rotators at or near ground level before installing them. It is much easier to make adjustment with your feet on the ground. And besides, we still were not certain that the TV rotator obtained from R&L Electronics would be sufficient to turn both antennas.
After some work on the ground we were ready to test. The antennas looked good on the Comet Analyzer and to everyone’s relief the rotator was more than sufficient to turn both antennas.
The time had come to get the antenna in place. Thankfully, Michael, K8RVR volunteered to do the roof work while I assisted from below. We had new LMR line for the beam and planned to reuse the feed line that was already in place for the 220 beam. That was when Murphy moved in. During our first attempt to erect the new antenna it appeared that the 220 feed line was not long enough to do the job. At this point the sun was setting and it was decided to postpone the erection of the new antenna for another day.
When the new day arrived we started by reworking the path of the existing feed line to see if we could free up enough coax to do the job. After 45 minutes of wrestling with the cable and undoing some mighty fine cable runs we had enough to make a go of it.
The new array is in place and working well. The Diamond has been relocated and is back in service too. I am busy trying out the new antennas. More later.
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