On Tue,3/31/2015 10:16 PM, Jim Thomson wrote:
temp install a bird wattmeter at the top of the tower. Then another in the
shack. Then apply exactly 1 kw..if using a 1 kw slug,
or 1.5 kw if using a 2.5 kw slug. Then measure what you get at the top of the
tower on the freq of interest.
There's another way. Make two swept measurements of the coax with a
Vector Analyzer at one end, with the other end first open, then shorted.
Export the data as S1P files to AC6LA's ZPlots Excel spreadsheet. His
spreadsheet will compute Zo and attenuation as a function of frequency.
If you know the exact length, it will plot Vf vs frequency, and
attenuation in dB/100 ft.
73, Jim K9YC
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