Update 'tools/meas.py'

Default impedance value fixed.

tools/meas.py

@@ -529,7 +529,7 @@ if __name__ == "__main__":
                 min_vswr[1] = m[0] # the frequency
 
               # R = meas_data[0] * 5V / 1023 * I
-              r = 20.0 * vswr # (m[1] * 5.0 / 1023.0) / i
+              r = 50.0 * vswr # (m[1] * 5.0 / 1023.0) / i
               meas_r.append(r)
 
               # P = meas_data[0] * 5V ^ 2 / r