Attic Antennas Are Go

Last week, I stuck a RCS-8V remote switch in the attic, and ran some RG-213 and a CAT5 control cable down to the shack in the basement. The switch has five ports (plus the common feed port), so there is lots of room for experimentation. Just in time for the Vienna Wireless Society 10m net on Thursday of last week, I got a 10m dipole in place, peaking near the center of the roof, with the arms following the sloping contours of the roof, running South to North, roughly in the center of the attic. The next day, I put up the Alpha Delta DX-EE multiband dipole, although the ends had to bend a little to fit. In principle, the dipole should tune 10/15/20 and 40m. The DX-EE runs flat from East to West.

I haven’t run an antenna analyzer over the whole set up yet, but I did try everything out in a trial by fire this weekend with the some contests. Before the contests, I did a quick comparisons between antennas.

For most purposes, the 10m inverted dipole and the 10m element in the DX-EE behave the same. The main difference in them is that I cut the inverted V to resonate near the voice segment and our local net, versus the DX-EE favoring the lower portion of the band and CW. Since most of the local net antennas are vertically polarized, I figured that having some vertical component in the local net signal would not be a bad idea. I’ve heard South America on both of them, and they seem comparable.

Comparing the DX-EE to the ground-mounted vertical out back, the dipole shines on the higher frequency bands. For the comparison, the DX-EE is tuned (if needed) via the radio’s internal tuner, and the vertical is tuned through the LDG AT100proII in the shack.  10m (and 12m) are barely tunable on the vertical. They *do* tune, but very little power is radiated. As for 15m, I tried calling CQ and watched the reverse beacon network.  The signal detected by K3MM was 18dB and 36dB above background for the vertical and dipole, respectively. For N7TR, the difference was less marked at 19 vs 22 dB. For 20m, I got similar results for WA7LNW 9 vs 17dB and for W0MU 7 versus 18dB. A number of stations received only the dipole signal.

On 40m, the vertical definitely wins. I am not sure if I can trim the dipole adequately to make it work on 40m, as the ends approach the sides of the attic, one of which is covered in aluminum siding, and the other of which is the concrete wall (rebar?) between our townhouse and the next one. The ends of the antenna take a jog right around the 40m traps, and the right angle turn may be too sharp. When it comes to lower frequency bands, the vertical is my only choice right now. I think this means that some sort of loop antenna is in the cards.

I took park in a few of the weekend contests. The WAE SSB contest ran all weekend, but was made difficult by two periods of unsettled solar conditions. Nonetheless, I made contacts with a bunch of countries including Austria, Belgium, Bulgaria, Croatia, Denmark, Estonia, France, Germany, Hungary, Italy, Luxembourg, Netherlands, Northern Ireland, Poland, Romania, Serbia, the Slovak Republic, Slovenia, Spain, the Ukraine, and Wales.  Not too bad for voice. Most of the contacts were on 20m, but some were on 40m, so both the attic and external antennas got a work out. I’m not sure if it  was the propagation, my antenna or just the nature of the contest, but I didn’t work stations on 15m.

While WAE was running in N1MM, I used my regular logging program to keep track of the other contests and events  going on over the weekend. I worked a fair number of stations in the Arkansas QSO party by voice and CW, and even a few parks on the air in Ohio and Indiana.

I had some firsts as well: I ran across a station calling CQ from Guyana, so that’s now in the log book. I also randomly dialed over to 60m and found that my tuner can match the vertical. I’ve never heard a QSO on 60m, so I tried calling and got a response from Chuck, KD8NLL. So, I guess that band does work after all.


	

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