In article .com,
" wrote:

I can't remember my formulas. If I have a transmitter that puts 1 watt
into a beam antenna that has a gain of 8.0DB what is my EFR? Please
show the work. I need to be able to demonstrate this to a customer.

Lenny-

Charles' method should work for you. If a customer asks, you need to
know more about the antenna's gain - is it compared to an isotropic
antenna (dBi) or compared to a dipole (dBd)? Note that 0 dBd = 2.1 dbi.
An antenna with isotropic gain of 8 dBi would have a gain of 5.9 dB with
respect to a dipole.

The isotropic gain is useful for calculating field strength at a
distance, but gain with respect to a dipole is easier to measure!

Fred