[TowerTalk] SteppIR gain

Jim Lux jimlux at earthlink.net
Wed Mar 16 19:08:31 EST 2005

At 02:44 PM 3/16/2005, Joe Subich, K4IK wrote:

>W4EF writes:
> > I have been thinking the same thing, Kelly. I think a 3
> > element SteppIR with 13.9 MHz parastitic elements and a the
> > 6.9 MHz MonsterIR driven element would be a big hit. Rotary
> > dipole performance on 40 and 30, and 3 element yagi performance
> > on 20, 17, 15, 12, 10.  Great for a 1/8 to 1/4 acre suburban lot.
>I've pitched this idea to Mike Mertel several times ... the
>problem is the change in impedance between the rotary dipole
>mode (40/30) and yagi mode (20/17/15/12/10/6).  It would be
>necessary to switch the impedance of the matching transformer
>(2.25:1 as a beam, 1:1 as a dipole).  Unfortunately, three is
>no provision to do that either in the driven element or the
>Like you, I think it would be a "hands down" winner for a great
>many users ... as long as they can handle the ca. 34' turning

No reason why you couldn't use two feedlines, right?  Probably mostly a 
mechanical implementation challenge more than anything else.

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