SWR = Zt / Zo applies only when both impedances are resistive. When Zt = 40 +
j30 ohms, the load is highly reactive. The coefficient of reflection rho is:
rho = (Zt - Zo) / (Zt + Zo) = 0 + j0.3333 ...
SWR = (1 + abs(rho)) / (1 - abs(rho)) = 2.0
73,
Maynard
W6PAP
On Tuesday, August 02, 2022 05:26:38 PM Jerry Stuckle wrote:
Incorrect. The VSWR is based on impedance - which is a combination of
resistance and reactance. A vertical at resonance will have an impedance
of about 35 + 0j ohms or an impedance of 35 ohms and a 50/35 or 1.43:1 SWR.
However, slightly off resonance it could have an impedance of say 40 + 30j
ohms, which would have a total impedance of 50 ohms (just an example for
ease of calculations) and an SWR of 1:1. The antenna is non-resonant at
the lowest SWR reading.
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