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My house is vinyl sided with aluminum around the windows. But will the inverted vee tune? will it adversly effect the radiation pattern of the G5RV ?

don
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4 Answers4

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But will the inverted vee tune?

Probably. If the G5RV is up in the air (and not, for example, stapled to a metal gutter or something else absurd), the metal around you windows will, at worst, have a minor effect on the tuning. It's unlikely to be anything that won't be compensated by the tuner.

Will it adversly effect the radiation pattern of the G5RV?

The G5RV already has a largely omnidirectional pattern that has lobes and nulls which move around depending on the frequency and how it's installed. It's possible that metal frames around your windows might change the pattern, but since the pattern is already so variable with frequency and installation specifics, such changes would not be "adverse".

The most important thing is to get the antenna in the air. A half wavelength is best. The reason: the ground significantly affects the radiation pattern. Of course, a G5RV is usually operated at many frequencies, but it can be mounted at the optimal height only for one frequency. Such are the compromises with a multiband antenna.

Community
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Phil Frost - W8II
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  • On an inverted V, is the 0.5 wavelength counted at the highest point or the lowest points? – Skyler 440 Apr 13 '15 at 13:41
  • @Skyler440 It's a rule of thumb, not a precise law. The actual optimal height will depend on ground conditions, how V-like your inverted V is, if it's a G5RV (which isn't actually an inverted V), surroundings, atmospheric conditions, and the path you are trying to work. – Phil Frost - W8II Apr 15 '15 at 11:32
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I make contacts all over the US with a home brew multi-dipole very similar to the G5RV using 200 mW out to about 8 watts. One day I went out and it had fallen down onto the roof, was dangling partly onto the gutter, etc. and I was still "getting out". I saw some changes in the SWR (but was still able to tune it), which is why I went outside to look at it.

Go for it! One fun experiment to try is run it awhile in one configuration, then go change something - bend one leg around, change the Vee angle - and try it some more. Great antenna.

Take notes and pay attention to the difference when it has rained, etc. You'll be surprised how much antennas are changing all the time anyway. Good luck!

Phil Frost - W8II
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noogrub
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I have a G5RV in my attic. That is also a possibility. It works fine as long as it does not contact any duct work or other metal. In your case, the amount of metal is minimal and should not present a big problem. If the house was also aluminum it would be a bigger issue. Happy operating. 73's Marty, KB4MG

Martin Buehring
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The simple answer is that ANYTHING will tune, but the pattern and efficiency are the real problems. We need more specific information to truly answer the questions. Too much metal in close proximity to the antenna WILL distort the pattern and change the feedpoint impedance/SWR. An antenna simulator can accurately simulate virtually any situation if you take the time to model it correctly and accurately. Among other things, it can model nearby structures of metal or conductive materials as well as the antenna itself. Some of us have these programs and can model it for you if it would really help. But please don't ask and waste someone's time when you already know the results.

Keith Martineau
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