Hi Andy,

The normal mode helix was covered in some detail in a 1974 (!!) edition
of Radio Communication with a set of empirically determined equations
for calculating resonance and winding dimensions.  Seem to remember it
was by the famous D A Tong, but I may be mixing it up with another
article.    I found the equations to be a good starting point from which
to fine tune helials for HF.   Used to have a copy of that RadCom, and
it may still be lying on a shelf somewhere.

I haven't been able to find this article - if you can find any more info I
would be grateful.

Regards,
Peter, G3LDO

e-mail <[email protected]>

Web <http://web.ukonline.co.uk/g3ldo>