[TowerTalk] Placement of coaxial matching stub at yagi feedpoint

[john at kk9a.com]

Are you eliminating the loading on the elements to make it work on 30m? 
If so, you can easily adjust the element spacing and lengths so the
impedance is 50 ohms.

John KK9A


To:	<towertalk at contesting.com>
Subject:	[TowerTalk] Placement of coaxial matching stub at yagi feedpoint
From:	"Bill Conwell" <bill at conwellpdx.com>
Date:	Tue, 13 Oct 2015 07:22:47 -0700


I'm doing some EZNEC modeling - looking at converting a KLM 40m 2 element
yagi to 30m.



The feedpoint impedance is about 35 + j25 ohms.  By shunting it with an open
stub of about 100 inches of 75 ohm coax, I get a good match.



I know I'll need to keep the open end of the stub away from the boom, etc.
But is there any other reason the stub couldn't be laid-along, and taped to
the boom?  Or coiled nearby?  I think not, but wanted to tap the crowd for
collective wisdom.



Tnx,



/Bill, K2PO