It's pretty early in the morning, but isn't that what the original
poster wants? To make an antenna physically shorter than normal? If
so, loading coils are the correct option. My only question is who would
need to physically shorten a UHF antenna in the first place?

Scott
N0EDV

Ham op wrote:

Loading coils do NOT shorten an antenna! They electrically lengthen an
antenna that is already physically too short.

What do you really want to accomplish?

wrote:

Hi All,

At 433 MHz UHF, I need to reduce the lenght of the dipole using loading
coils or a better method.

I need to know if there is a antenna program or a method to determine
values and location.

tnx de KJ4UO.