[Lowfer] Oh, CRAP! - calculations

[John Andrews]

Andy,
> 15,858uV converts to 15.858mV which roughly equals 23.8dBm.
> 23.8dBm roughly equals 240mW or .24 Watts into a 50 ohm load,
> and measured at a distance of approximately 50 feet from the
> transmitting antenna.

No, sorry. The spec is an electric field strength of 15,848 microvolts 
per meter at 30 meters. This has nothing to do with a 50 ohm load. You 
cannot make such a simple conversion.

The electric field strength from a half-wave dipole is a complicated 
expression, but in the far-field and in free space, it reduces to:
E = (SQR(49.2 * P))/D  where
E = field strength in volts/meter
P = power in watts
D = distance in meters

If you hack that out, you will find that for a field strength of 15,484 
microvolts/meter at 30 meters, you would need 4.6 milliwatts.

John Andrews, W1TAG