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Roy, W7EL wrote:
"Do the proper substitutionn and you`ll get the correct answer." Yes. The warning also appears on page 137: "In developing the field expressions for the short dipole, which were used in obtaining (5-56), (5-56) is the value of radiation resistance, the restriction was made that lambda is much larger than the length of the dipole L." No problem there, Reg specified a short monopole. Kraus does a sample calculation for a short dipole. I used Kraus` data and got the same answer when duplicating his calculation. But Reg was not asking for an answer to a specific problem. Reg was asking for the value of the constant in a formula of the same form. Kraus gives it as 80 pi squared for a dipole.. This is 790. We know that a monopole has half the resistance of a dipole. Example: 73 ohms and 36.5 ohms. 790 / 2 = 395. That`s not a resistance, it is only the value of a constant which must be multiplied by (L/lambda) squared to give the radiation resistance of a very short monopole. Best regards, Richard Harrison, KB5WZI |
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