computing partial frequencies -- Call to Arms

[Ron Nossaman]

>Ron;
> In radio school they taught us to use a constant of '468' when determing the 
>length of a long wire antenna radiating leg.  The only answer I ever got for 
>where this came from was to be told this is the log of electro magnetic 
>energy speed in a vacuum, i.e. 'space'.  Still don't know where it came from 
>or what it really means :-(
>Jim Bryant (FL)

Hi Jim,
That is PRECISELY my point. If they had told you to use the constant
representing the log of electromagnet energy speed in a vacuum, but hadn't
supplied you with a number, you wouldn't have had ANY means to figure out
how long to make the antenna unless you spent who knows how long trying to
chase down that "486" figure from some other unnamed source. Hardly seems
like a useful educational technique, does it? Tell you what. Try to put
together a usable spreadsheet formula from either of the bits of
information that Richard B and Richard M posted and get back to me. I'll be
happy to include it/them in the collection. That's not to pick on the
Richards, because they tried to help with what they had available. See, I'm
not really interested in picking these formulae apart and seeing what
they're made of. At this point, I'm interested in trying out as many
WORKING formulae as possible, comparing their output, and then making them
available everyone for others to pick apart and evaluate to their hearts'
content. Bless them, if they're capable of doing it, but they have to have
something to work with. When the assignment on the first day of class is
"Acquire an elephant", there aren't going to be too many folks passing
Zoology. 

These, and other formulas seem to be widely known and discussed, but
where's the accessibility? It seems that we make a big deal out of sharing
information and then don't. I can see that one wouldn't post proprietary
information, or would honor a request not to disseminate sensitive
information, but what's the problem with posting stuff like this? Wouldn't
this be the industry equivalent of "public domain"?


Ron N