But if the antenna is too short (resonates above your desired frequency) then it's a little more trouble to add wire to each leg to bring down its frequency of resonance where you want it.We have a team of 2 people to build a directional wireless antenna (cantenna) for my IT103 Networking class.Note: To avoid cutting the wire, I usually just fold back each end of the antenna wire on itself and tape it tight if it's insulated wire - or twist it back on itself if you are using bare wire. If the antenna is too long (resonates below your desired frequency) then it's not a problem: you just trim each leg a little at a time until you reach lowest SWR.NOTE: if you start by giving the calculator your *desired* frequency of operation, the inverted V - when installed in its final position - may be still end up too short or too long, depending on the environmental conditions mentioned above. The influence of the ground conductivity and dielectric constant becomes an increasing factor.The resonant frequency of the inverted V is lowered (see the theory behind this at the bottom of this page).As the two sections of the dipole are lowered below the feed point, the angle between the two legs decreases:
The angle below the two sections of a horizontal dipole is 180 degrees. In the case of the inverted V we must add - to the list of environmental variables influencing the half-wave dipole - the angle between the two legs of the inverted V. It is adjusted to take into account the special characteristics of the inverted V. The formula used by the calculator to compute the wire lengths for the inverted V is based on the formula for a half-wave dipole. Will give you some leeway to trim the wire ends back if the inverted V resonates too low for your purpose when installed in its final position.
Than that of a dipole at the same desired frequency of operation.
Calculator above will give you a wire length for the inverted 'V' which will be about 4% shorter
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