ARROW Communications Association

Thanks very much for your input, anonymous. If you wouldn't mind, I'd like to converse with you directly on the topic at some point.

I acquired a Butternut HF9V for $50 at a local swap, replaced the 40M cap, replaced corroded hardware with new stainless, and now just have to put new linear loading wires and coax feed on it. Then I can clean the tubing connection areas (previous owner had some goo on it, doesn't look like no-alox, either), put it up, and construct a radial system for it. First installation will be based at 5 feet at the corner of my deck, with elevated radials in a couple-or-three directions across the yard (got some 3 conductor rotor cable to minimize impact). I too have been convinced that elevated radials are the only way to go.

Then the tuning exercise, which some have said is easy and others have said was very difficult (the coils were mashed around a bit in transit by the previous owner). Hopefully the MFJ-259 will make this easier.
Once it is well tuned I hope to move it intact to a tripod on the roof at 20+ feet and possibly add a few more radials for good measure. My 5 watt capability should do a good deal better then.

My current vertical is a tribander driven element tied vertically in my 25' oak tree, the bottom end about 8 feet above ground. It worked great all Winter (and almost always beat my trap dipole at 25') but has seemed increasingly lossy as the leaves have grown around it and in contact with it. It might be better if it was insulated, but it will either be a good antenna to use again next Winter, or I can take it down and rely entirely on the Butternut.

So until I get the Butternut up and feel like playing (have time), my plans for an 80M inverted L (possibly "fan vertical") are on hold.
Any more thoughts, information, or experiences? Thanks much for the input! 73 de kt8k - Tim
PS - my intended use is leaning toward DX.

Your purpose is critical. A vertical is NOT a nearby-QSO antenna.

From Ann Arbor, if you want to work with a guy in Toledo on 80 meters, you can do all you want with a vertical, but it will be very difficult. The vertical's angle of radiation is way too low. A dipole at 20 feet might not be much better because a dipole at 20 feet sends more energy into the earth than anywhere else. What's left goes mostly straight up. Don't even think about "NVIS" - that's a military designation for an antenna that, by intent, can't get a signal out of your backyard, but works inside your backyard (depending on backyard size). If a diple at 20 feet can make a QSO, a dipole at 50 feet will do it better. The only advantage with the dipole at 20 feet is if you want to make sure you can't be heard on the west coast! Also, a horizontal loop is sort of ho-hum. If they're less than one wavelength in total wire length, they're inferior to a dipole as they not only aim up and down, but they actuall narrow the up/down beam!

However, if you want to concentrate exclusively on DX (on 80 meters, that might be Hawaii), then the vertical is a fabulous choice. And others are right. Two elevated radials has been shown to outperform 120 on-ground radials for AM broadcast, and it works on 80 meters also. You can tune both the vertical element AND the radials, using the same inductive techniques or "capacity hat" loading. I have a full-sized 40 meter vertical. 33 feet of aluminum irrigation tubing. Underneath I have four untuned, too-short radials. My signal into Asia dominates anybody else within 100 miles of me, unless they have a 3 element 40 meter Yagi at 75 or more feet. On 80 meters, I do nothing more than use an antenna tuner into the very same antenna. I've done nothing to the antenna to make it a better 80 meter antenna. On 80 meters, my signal does not dominate, but I routinely work Asia with it. I've never heard Europe on 80 meters - not yet.

Back to your multi-band dilemma. Make an antenna that is 3/8 wave long at the lowest frequency and feed it with any of the common parallel-wire transmission lines. 300 ohm, 450 ohm, etc. Inside the shack (or just outside before you go inside) use a 4:1 balun to transform to coax. Offset the feed point on the antenna away from the center - go about 15 to 20% down the length of one leg. Doing so makes the antenna impedance "better" that is, on the ham bands it won't be zero or infinity, but always in between. The parallel-line transmission line becomes a better match for the antenna. You see, a wire antenna like this has the lowest impedance at the half-wavelength frequency and it's going to be about 50 ohms. At every other freqeuncy, the antenna is higher impedance. So by using a 300 or 450 ohm line, the SWR is going to be about 6:1 where the antenna is 50 ohms, and it will generally be lower on all ham bands. That's the SWR referred to 300 ohms. Through the 4:1 balun, you transform it down so that it now looks like 4 or 5 to 1 or better at the rig (reference 50 ohms) and the rig's tuner can handle it. By the way, the offset feed is referred to as a "Windom" feed.

If you can get the power into the shortened antenna, the antenna efficiency will be imperceptibly less than the "full size" dipole, as long as it's not TOO short. If the antenna is only 1/4 wave long (instead of the standard 1/2 wave) you typically lose about 1dB. 1/8 wavelength long and you might lose 3dB. I use a 40 foot long flat-top like this on 80 meters and my signal is as audible as the rest of the nuts on 75 meter SSB using the same power.

I recommeded 3/8 wave long. You can go shorter, but 1/4 wave long and shorter is not only going to lose some efficiency due to I-squared R losses, but the SWR will get pretty high and your rig's internal auto-tuner might not handle it well. Neither will an ordinary external MFJ type tuner.

But there's a fly in the ointment. You only have a 20 foot height to deal with. That can work modestly well on 40 meters but may be disastrous on 80 meters. The vertical is a better bet if you really can't get up at least 30 feet.

IMO with wire antennas like this, 30 feet high on 40 meters will let you work about anybody you hear on CW, and about half what you hear on SSB. On 80 meters, your QSOs will start to have a fair amount of time in between them.

At 40 feet height, 40 meters will be easy, it will be rare that you can hear someone and they can't hear you. On 80 meters, you'll have to make sure your tuner is really peaked, and if you're running SSB you might need to try the compressor (gently! it's easy to overdo compression) but you'll make QSOs.

At 50 feet height, you will feel invincible on 40 meters, and you will be a full participant in the 80 meter SSB stuff at night.

My "wire antenna" comments assume that you're after general operating, where you just want QSOs and don't care if they're local or DX. You can get some DX on 40 with a horizontal wire, but it's hard on 80.

Dang I love antenna chatter!

I have used a Butternut vertical over a dozen tuned radials mounted on the roof. Research shows that the antenna is much more efficient over elevated as opposed to buried radials. Even two tuned radials (each one quarter wave long), will provide a more efficient radiator than if the radiator is over a half dozen buried radials. My experience indicated that this radiator and radial combination with the antenna base at 28 feet above ground had a radiation angle lower than 20 degrees.