Loop Skywire Antenna & Remote Tuner

Now that I’ve had this antenna setup for a few years now I have come to recognize the drawbacks. The biggest of these is a lack of tuning bandwidth. This resulted in having to retune the system even when changing frequency by only a few kilohertz, very annoying. After playing with a MFJ 926B remote automatic antenna tuner at Field Day┬áthis year I decided to modify my antenna to make use of one of these units and see if it improved my operation. The 926B is actually pretty similar in design to my LDG tuner except it is mounted in an enclosure suitable for use outside and can be powered via coaxial cable using a BiasTee power injector so no extra cables are needed. It automatically initiates tuning when a mismatch over 2:1 SWR is detected while transmitting and it saves the match settings to memory.

The idea of a remote antenna tuner is that it allows the tuner to be located at the feed point of the antenna. This means that the tuner is matching the impedance mismatch of the antenna only; not the antenna, plus feedline combination that it was dealing with previously. This allows the tuner to find a match much more easily and also results in a much better tuned bandwith because the only variable changing is the impedance of the antenna not the impedance of the antenna and feedline combined.

A side benefit of this new setup is that in order to reach the tuner as it is mounted on the side of my house I had to add some wire to my antenna which now contains approximately 270 feet of wire. The antenna is now solidly resonant in the 80 meter band. In addition to adding wire I separated the feed point in the air by about 10 feet. This allows the wires to drop to the tuner at an angle in order to keep the shape of the loop as intact as possible and prevents the two ends from contacting or crossing one another. I also installed an Alpha Delta TT3G50 surge protector in the coax line from the tuner.

In the short time that I’ve had this setup on the air I have been very pleased with its operation. To tune the system I switch to CW mode on my Icom 7200 and transmit a tone (with the power turned down to 10W). The tuner then initiates its tuning cycle and matches the antenna. This generally only takes 2-3 seconds, much faster than before. It also tends to find much better matches and regularly achieves close to 1:1 SWR. As hoped, the tuning bandwidth is greatly improved as well and I am no longer required to retune every time I move around a band. This new setup is also much cleaner looking on the house with no ladder line or balun, just wires going to the low profile tuner and a coax run along the brick.

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