Tweaking 80 meters on multi-band dipole
 

I have a multi band dipole with traps/loading-coils. I would like to raise
the resonate frequency of the 80 meter band by 200 KHz. Can I simply shorten
the 80 meter part of the dipole by the proportionate part of 200 KHz?



I.E. - ¼ wavelength at 80 meters = 66.9 ft.



200KHz/3.5MHz = .057



66.9 ft x .057 = 3.8 ft.



If I shorten each leg of the 80 meter section of the dipole by 3.8 ft, will
that raise the resonate frequency reasonably close to 200 KHz? (If this were
a simple monoband dipole, I would not hesitate to lope off the 3.8 ft. But
with the coils, I'm not sure what the effect will be.)



BTW, this is a Delta Alpha DX-LB plus. I realize shortening the 80 meter
section will also affect 160 meters. This should not be a problem because I
want to raise 160 also.


--
Bob D. ND9B

Tweaking 80 meters on multi-band dipole
 

On Mon, 8 Oct 2007 13:01:56 -0400, "Bob D."
wrote:

(If this were
a simple monoband dipole, I would not hesitate to lope off the 3.8 ft. But
with the coils, I'm not sure what the effect will be.)

Hi Bob,

By this parenthetical, it seems you already know this won't be easy.

Simple way to do this is loop back, say, 3 feet of wire and
electrially attach it to itself. This shortens the wire without
cutting it.

73's
Richard Clark, KB7QHC