I had to calculate my radiation resistance to comply with the license
requirements on 600m.
My antenna is a base loaded inverted-L: 43-feet high and 122-feet
long*. Radiation resistance was taken from a EZ-NEC model as 0.83
ohms. Ground resistance was measured with an antenna analyzer as 18 ohms.
efficiency = 0.83/18 = 0.046 Running transmitter output of 100w,
Total Power Radiated = 100*0.046 = 4.6w
EIRP = 4.6*1.48 = 6.8w anti-Log (1.7 dB) = 1.48, gain = 1.7 dB
ERP = EIRP/1.64 = 4.15w which is the parameter wanted by the
licensing authority.
go to: http://www.kl7uw.com/600m.htm
click on the EzNec model for the antenna analysis and ERP calculation
for the rest.
*Note the antenna was shortened from 130 to 122 feet to improve
tension on the top-hat section.
73, Ed - KL7UW
http://www.kl7uw.com
[email protected]
"Kits made by KL7UW"
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