"/* frank */" wrote in message
...
I can install only a dipole of about 10 meters
(as inverted V).

Is there any project, any commercial antenna
of such length, that allow me to work all band
7 - 14 - 21 - 28 MHz ?

Thanks

It's probably going to work like crap on 7 MHz. Consider buying
a GOOD tuner, and also try tricks like feeding the coax
common mode (shield and center tied together) to run your
ten meter dipole as a top loaded vertical wire. This assumes
you can run the coax or balanced line in a straight run away from
existing structures. You'll also need a good ground or a few
on the ground radials for the antenna to work against when
it is being run as a vertical. Don't be afraid to experiment.

Pete