Hello Pete,
Yes, you are quite right if you are operating only on one band. I use my coax
for feeding a triband stack and it needs to be flat across that portion of the
spectrum. Parenthetically, I had a devil of a time getting a respectable SWR
with my stack last summer after 3 years of no maintenance. I finally had to
just make everything flat to 50 ohms with UNUNs, etc. and it finally started
behaving. Before, I just went direct from 50 to 75 ohms and vice versa. That
introduced all kinds of strange impedances back in the shack at different
frequencies.
73/Mike, N7ML
Pete Smith wrote:
> At 06:29 AM 2/10/99 -0500, L. B. Cebik wrote:
> >>
> >Mike is exactly right. I failed to note--although the article makes
> >clear--that the series matching system using transmission line sections is
> >a monoband matching scheme. For triband and other wide band use, ununs
> >are preferable.
>
> Except that they introduce several additional connectors into the line,
> each of which is a likely failure point. As someone pointed out, you can
> always make the 75-50 ohm transition at a convenient half-wavelength point,
> and run the rest of the way with 50-ohm coax, so the length issue really
> isn't terribly awkward.
>
> 73, Pete Smith N4ZR
> n4zr@contesting.com
>
> Loud is.
>
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