I'll rely on the calculation from the freeware program "Mobile Antenna". That
program allows variation in coil designs to be specifically input as a variable.

If you have a better answer or method then please provide it.

The original post is basically asking if 100 watts can be run from a 706 in a 60
meter mobile. The answer is YES. Why? Because an eight feet long antenna is
substantially less than the reference dipole. [Typically it is -10dBd].

/s/ DD, W1MCE

Owen Duffy wrote:
Dave wrote in
:

...

3) [Rule of thumb] The gain is proportional to the effective aperture
in square wavelengths. So, as mentioned in another reply,
approximately, the ratio of length of the mobile antenna [~8 feet] to
the length of a 1/2 wavelength antenna for 60 meters [~93 feet] yields
8.6% efficiency. So, 100 watts from an IC-706 [series] yields ~9 watts
effective radiated power. Conclusion, 50 watts ERP on 60 meters with a
9% efficient antenna would require 555 watts into the antenna.

...

It certainly is ROT that in the general case, and in this case, that you
can run a tape measure over an antenna to calculate the aperture area and
in turn calculate gain.

Can you explain how your method deals with capturing the effects of a high
loss loading coil vs a low loss loading coil in such an antenna?

Owen