[Elecraft] Feature request K4 ATU - nearest band tuning

[Magnus Danielson]

Hi,

So, beyond the fun of doing QSOs, I also listen to intermediary bands. 
Sometimes however it is clear that it would be good to have the ATU tune 
up. So the manual procedure I do is to go to nearest band, tune there, 
and go back. This way I will not transmitt out of band, and the tuning 
is not really perfect for my listening, but I have noticed that 
listening condition becomes better so this approximation kind of works. 
Now, it would be great if just hitting the ATU TUNE would do this for me 
in the background, so hence a feature request.

Technically, one wants to use the mid point f2 = sqrt(f1*f3) where f1 is 
the upper side of lower band and f3 is the lower side of the upper band 
from the frequency fVFO. If fVFO < f2, then tune on the upper side of 
lower band, else tune on the lower side of upper band.

The radio will need to know the legal borders of the bands for the 
country to do this. Also, you most likely want to have a configuration 
variable to enable/disable this feature. When disabled, todays behaviour 
of refusing tuning can be used.

Cheers,
Magnus