Dipole: Difference between revisions
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(added general info on dipoles, diags and formulae for centre fed and ocf dipoles) |
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== Off Centre fed dipole (OCF dipole)== | == Off Centre fed dipole (OCF dipole)== | ||
As the name suggests, the OCF dipole is not fed from the centre | As the name suggests, the OCF dipole is not fed from the centre. | ||
L is calculated from the formulae above. The dimensions D1, D2 and D3 are found using: | |||
<math>D1 = 0.38L</math> | |||
<math>D2 = 0.62L</math> | |||
<math>D3 = 0.14L</math> | |||
[[Image:Vk4yeh_ocf_dipole.jpg|left|550px]] | |||
Revision as of 16:40, 7 March 2008
Dipole antennas are "two sided' in that they are fed from a point between the two ends. In is simplest form, a dipole will be centre fed, with the total length being the same as the frequency of transmission.
Simple centre fed dipole
Dipole length for resonance is calculated using either:
<math>L = \frac {468}{frequency(MHz)}</math> for total length in feet, or,
<math>L = \frac {285}{frequency(MHz)}</math> for total length in metres.
Half wave dipole
These are centre fed, but each arm is one quarter of the wavelength of the operating frequency.
Off Centre fed dipole (OCF dipole)
As the name suggests, the OCF dipole is not fed from the centre.
L is calculated from the formulae above. The dimensions D1, D2 and D3 are found using:
<math>D1 = 0.38L</math>
<math>D2 = 0.62L</math>
<math>D3 = 0.14L</math>
