Ian, G3SEK wrote:
"Therefore the Bird does not directly sense RF power."

Problem with that statement is that to the uninitiated it makes the
indication suspect. A voltmeter doesn`t measure volts directly. The
ordinary voltmeter measures current scaled by a multiplier resistor.
Wish you and Walt would knock off the nonsense.

A Bird senses all it has to sense and legitimately converts it to a
reasonable indication of watts. The Bird can do so thanks to Ohm`s law,
and that`s that.

Best regards, Richard Harrison, KB5WZI