Hello Jeff.
25 Aug 97 00:25, Jeff Kincaid wrote to Jeff Edmonson:
 JK>
 JE> >> Well, I always thought it took a different formula to calculate
 JE> >> the length of a vhf antenna as opposed to an HF antenna.
 JK>
 JE>> A dipole is a dipole is a dipole - don't matter if it's for 160m or
 JE>> 70cm.
 JK>
 JK> Jeff, those wavelengths differ by a factor of nearly 230.  Since
 JK> there's a practical limit on how thin a wire can be, I figure you're
 JK> talking about a 160 antenna made out of cable about two feet in
 JK> diameter. There is some merit to that, since it might have a low SWR
 JK> over the most of the band (maybe all of it?), but I think it's going
 JK> to weigh several tons.  Of course I'm being absurd, but my point is
 JK> that wire diameter affects the length of the antenna when the diameter
 JK> is more that a tiny fraction of the wavelength, as it is at VHF and
 JK> above.  The formula is in the Handbook (ARRL's for sure, but probably
 JK> any of them).
The 468/FMhz fine print tells you that.  Any antenna you make with that 
formula will have to be tweaked to get the VSWR down to a good working level 
in most cases.
At VHF/UHF I've found the formula to be quite accurate using 3/16" aluminum
round stock.  But I've also designed an adjustment in my antennas as well.
... AHHHHHhh! Thank you Nurse Morris, that was some surprise.
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