On Wed, 19 Nov 2008 22:53:28 -0800, Richard Clark wrote:
On Wed, 19 Nov 2008 22:45:19 GMT, Rich Grise wrote:

But I've been searching the web for some weeks now, and I can't seem to
find any kind of formula, except there was this program I downloaded -
LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or
Uzbekistani - one of those East Yurp languages. Here's a screen snap:
http://mysite.verizon.net/richgrise/...rog-Output.gif

Which I went through pretty much by-guess-and-by-gosh - can anybody read
that stuff?

Someone else has already provided the translation, so that will take care
of some of the wholes in data entry and reading.

There are a lot of factors I don't know about, like "Tau", and all of the
specific designs on the web are flat - something is telling me I want one
of those pyramid-shaped ones, but I really don't know the difference
(between that and flat) - it's probably something to do with bandwidth or
F/B ratio or whatever.

Tau is related to the shape of what you call the pyramid, or more actually
to the angle of the taper. This defines the smoothness of matching across
the span of frequencies you entered into the program. As you can see, it
also relates to the available gain. Another correlative is it also
relates to its length. All of these things are trade-offs that lend to
the rule of choosing what you want most and giving up on the rest.

I note elsewhere that you wanted something about 1 foot long. There is a
Tau that will give you this boom length, and you got it on the first
guess.

So, how do I pursue this? It'd be nice to have a program that will
calculate the whole thing for me, but am I dreaming? If I want to send
myself to Log-Periodic School, where should I start?

You should start building what your screen shot gave you IF that is the
span of frequency you need (already questioned by other correspondents).

73's

"Best Regardses"? ;-)

Anyway, thanks for this - I'm feeling a lot better about this project now
thanks to your help and that guy that translated it for me (forgot the
name, but he knows who he is - Thanks Again!);

I might even start cutting wire[1] and soldering this weekend! ;-)

Thanks!
Rich

[1] GTAW (Gas Tungsten Arc Welding) filler rod, with some coppery-
colored coating that solders even better than copper, about .030 dia.,
and as stiff as piano wire.