My first HF antenna at this QTH was a 90' wire tuned by an ICOM AH-4 auto tuner. The trees were small, all outdoor antennae verboten, and stealth was the name of the game. The tuner was mounted to the wall outside, just above the basement shack, and though it was rated for 80 thru six, it worked surprisingly well on 160 -- though highly directional. All went fairly well until the aluminum siding was replaced by vinyl; all manner of bizarre RF issues suddenly intervened.
The trees having grown, as trees are wont to do, I decided to put a wire dipole up in place of the AH-4. Casting about for a design that would fit and be well hidden from the antenna nazis, I pored over the ARRL antenna compendia in search of some magic solution to my lot and my desires to reach as low on the bands as possible.
I decided to try Louis Varney's ubiquitous G5RV. A host of complications badgered me -- the 34' feed line was much longer than I could manage and the wire itself was a bit long for the only spot I had that would hide it.
Irv (I cannot now remember his call, but he was the QRZ curmudgeon from Sacramento who lurked in the Q&A forum waiting a chance to pounce upon the innocently ignorant awardees of modern licenses, skewering them for their lack of technical prowess) put me on the griddle about the G5RV and kept insisting that I read up on "conjugate matching." I confess, at the time, I thought he was citing a marriage manual.
I was led, by the nose perhaps, to obtain a copy of "Reflections," Walt Maxwell's (W2DU) classic treatise on transmission lines and antennae, and Mr Maxwell led me to understand that those dreaded SWRs that threaten one's peace and sleep are highly over-rated as gremlins waiting to destroy one's station. If there is any single book that has influenced my on-going development as an amateur, I would put Reflections at the head of the list.
I put 100' of insulated, 12ga wire into the trees, fed it with twisted 300Ω window line cut, not to some length from a wavelength table, but merely to fit the distance needed, attached a 1:1 current balun and made the final entry with a minimal length of coax. That antenna, with a good transmatch, works well from 80 through ten, yielding good performance -- though, as with any multi-band dipole, the lobes vary and coverage changes around the rose; also, I cannot get the antenna high enough to achieve a really low launch angle. Compromise is a large part of what I have to do.
My first rig was an IC-725, and I used an old Heathkit 2060a tuner. Antenna performed like a champ. Growing a bit bolder, I bought a used IC-746Pro and shipped it off to Bellevue WA and had the techs at ICOM wring it out and bring it up to spec (ICOM would update any rig still in production free-of-charge). I swapped out the Heath tuner and substituted Martin Jue's fine 993B auto-tuner. The antenna continued to perform flawlessly. Finally, I retired the 746 and brought in a brandy new 756ProIII and added an AL80B with a full-limit Versa-Tuner (both of which I rarely use -- I bought the amp specifically to work Peter I Island but ended up doing so barefoot).
A bit over two years ago, my neighbor's Bradford Pear tree invaded my fenceline during a storm, taking out the antenna mast, snapping the dipole legs and supports, and bringing the entire system down in a tangle.
I have now replicated the antenna, and I hope shortly to have it back in the air. Alas, my schedule is complicated and crowded at present, so I cannot predict when I will be ready. I look forward to meeting some of you on the air; I will post on the sked forum when I can.
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Originally Posted by W3MIV
