Topband: Re: SteppIR

[Ford Peterson]

Martin, et al...

The parasitic elements of the SteppIR are not grounded.  I have one in my shop right now.  There is no electrical connection to the boom whatsoever.

Having used the SteppIR now for well over a year, I can tell you that the hat produced by the SteppIR is most interesting.  My 3 el is mounted at 45' on a grounded Rohn 25G tower, guyed with phyllistran guys.  A vacuum relay is mounted at the thrust bearing plate.  The common of the relay is attached to the bearing plate at the top.  Each leg of the relay is attached to a hat wire.  One wire extends about 25-30 feet out.  The other extends out about 120 feet.  There are two shunts on the tower.  The 160M shunt attaches to the big grip on one side and extends all the way to the base.  If memory serves me correct, it's about 2' off the tower.  The second (80M) shunt extends out about 1' off the tower and is mounted at about the 33' level.  

Using the 160M shunt with the SteppIR at the 20M setting, I get a near perfect SWR at 1.820.  QSY to 1.840 and I need to set the SteppIR at 17M setting to maintain a SWR suitable for use without a tuner.  At 1860, the SteppIR must be set to 15M or 12M to maintain SWR match.  At 1.890, the antenna is only usable with a tuner.  At 1910, I cannot get a match even with the tuner.

My guess is that the feedline on the SteppIR runs through a grounded header at the base of the tower, which electrically connects the driven elements of the SteppIR to the tower.

The same effects are not visible on 80M.  I have no clue as to why.  An extensive soapbox on the ARRL website shows pictures and a further description of the system.

http://www.arrl.org/members-only/contests/results/2002/160-Meters/sb.html

Ford-N0FP
ford at cmgate.com

----- Original Message ----- 
From: "Martin" <dl1iaq at gdxf.de>
To: <topband at contesting.com>
Sent: Sunday, April 11, 2004 7:21 AM
Subject: Topband: Re: SteppIR


> Hello topbanders ,
> thank you for your input.
> The opinions seem to differ a lot.
> 
> I will wait for a reply from Earl, K6SE.
> He said, he will ask the people of SteppIR at Visalia, if
> the parasitic elements are grounded or not.
> 
> 
> -- 
> Mit freundlichen Grüssen
> 
> Martin                 mailto:dl1iaq at gdxf.de
> 
> 
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