"Ralph Mowery" wrote in message
nk.net...

"John Smith" wrote in message
...

By the time you get to UHF it is difficult to use coils. Baluns are
usually
made of coax or some of the very small hard line like less than 1/4 inch
in
diameter. The coax is just a fraction of a wavelength.

Hi, Ralph -

Yes, I can see that now. A little over two turns of RG58, tightly wound, on
a .75 inch diameter is about right to be resonant around 440 MHz. However,
the resonant frequency moves with compression and expansion of the coil (not
unexpectedly) making it difficult to settle on the dimensions.

The problem here is that I must have no leads on the coil while
experimenting because the leads affect the frequency. Later, when I create
the coil at the base of the antenna, I will not be able to determine the
coil's exact resonant frequency and adjust it for my frequency of operation.

I think I'll give up on this idea.

Thanks for your comments.

John