[TowerTalk] 50 ohm yagis (40M2L) ?

[Kevin Normoyle]

On 7/18/2010 8:18 AM, john at kk9a.com wrote:
>    BTW, it is pretty easy to design a 2el
> yagi with 50 ohm impedance eliminating the need for the match.
>
> John KK9A
>    

40M 2L 50 ohm impedance? with reasonable gain/f/b/swr bandwidth? I don't 
think so, or I couldn't do it
(with my boom length and full length elements)
Am I missing something?

Actually I did create one by accident. If you off-center feed the DE, 
you can get a 50 ohm match without too much loss in the other metrics.
I thought that was interesting. I saw someone proposed that elsewhere, 
and it actually does work. It would be possible mechanically, but there 
is a loss in gain.

Does anyone have a 40M 2L with 50 ohm input, with no matching 
components? Well I guess a moxon does it, and maybe some dual-driven 
things? what am I missing? I thought a simple 40M2L can't, as far as I 
tried.

-kevin
ad6z