Feature

Backyard Stealth Project

Ken Wendel, W5RPS

   Living in an HOA subdivision requires some creativity in antenna systems that won’t upset the neighbors. Hence my search started after moving here to Hickory Creek for an antenna that would satisfy the needs of my neighbors, as well as my own. The first antenna I tried was a CrankIR (SteppIR company). This antenna is a portable vertical, easy to set up, had good performance figures, and was somewhat stealthy. The antenna performed well but was somewhat sensitive to noise in this environment. I spent most of the time using the CrankIR outside of the house in State and National Parks. But I still needed a better antenna for the QTH while remaining off the neighborhood radar.

   After doing some research, I discovered the magnetic loop antenna. The advantage of the mag loop reported in the literature was “low noise” performance on receive—up to 20 dB lower! Most of the commercial options, however, were receive only and those with transmit capability were limited to about 100 watts. I considered some of these but was aware that a low power option for an antenna that sits near the ground did not some like a good idea for an antenna with about the gain of a dipole. While these antennas make up some of this with the low noise performance on receive, the lack of higher gain for transmit was a showstopper for me.

   Then I saw an advertisement for a magnetic loop from an Italian company, Ciro Mazzoni. This is the “Baby” model and covers 40m to 10m and is rated for 450 watts to 1 kW. Construction is outstanding and gain performance is near that of a dipole. The antenna has some directional characteristics with a front/back ratio of 6 dB! The best thing about the antenna is that it was dirt cheap!! (Yeah, right). After some lengthy discussions with the XYL about the advantages of this antenna and saving my pennies I finally bought the antenna along with a tripod for backyard setup.

   Which brings us to the present project. The tripod worked okay, but the antenna weighs about 25 pounds. The tripod at minimum height was too high for me to set the loop up by myself which meant that whenever I did the setup, I needed help to lift the antenna on the tripod. Then the minimum performance height is 4.92 feet. You’re probably asking by now why was it that I didn’t just set up the antenna permanently? It is certainly durable enough to withstand wind and rain.

   Well, I didn’t want to attract a lot of attention with something strange looking in my backyard and mowing around all of the guys needed to set up the tripod was a pain. So I looked for a crank up pole that was low enough when down to easily set the loop on top and would crank up the loop to the minimum acceptable height of 4.92 feet and would accommodate the extra weight of a rotor since the antenna is directional. I found just the candidate at the B&H photo in NY. The pole was made by K&M in Germany, but it was on backorder. I found a used one at Sweetwater and received the pole in about three days. It took only a day to dig the hole and place a 20-inch support piece along with a 9-inch adapter to mate to the bottom of the pole.

   I’ve done some comparisons between the CrankIR and the Mag Loop on 40m and 20m. Certainly signals are much more readable without the noise issues on the loop compared to the CrankIR which makes the Mag Loop much more usable at this QTH. It also is not visible to the neighbors with fenced back yards. DX has been poor, but I have worked Europe and Africa on 20m in recent months. Both antennas have low angles of radiation which helps with the DX and signal strength on receive was comparable between the two. Conditions aside, I think I have solved my HOA issues and upgraded my shack.

73 Ken, W5RPS

©2014-2020 Metrocrest Amateur Radio Society, Inc. All Rights Reserved