[Top] [All Lists]

[TowerTalk] Re: Stacked StepIrs

Subject: [TowerTalk] Re: Stacked StepIrs
From: "Howard Klein" <>
Date: Thu, 06 Nov 2003 22:17:09 +0000
List-post: <>
I am attempting to answer the various posts which differ a bit, with a single E-mail. If I can answer other questions feel free to e-mail on or off reflector. I am certainly looking for a few answers myself, namely a means within my capability to objectively determine if and what I have accomplished.

I think the stack works quit well. All opinions are subjective based on my experiences over my ham career. In the past I have stacked X-9's and have used a Telrex 326 as well as some lesser antennas. I can not come up with a reasonable way to gather more objective criteria.I believe the flexiblity of being able to use antennas at different heights is an advantage filling in elevation angles as well as both in phase which does lend an additional gain factor. I currently use the Comtek Stack2 Yagi System. It is very simple and straight forward. I previously used the Array Systems Stack Match which at the time offered only the three stack yagi box. This was a bit cumbersome with only a 2 stack and in my case did not supply the result I sought. I stack 2 antennas both monobanders at any given time (4 el SteppIR's). The top is at 75 feet and the bottom at about 40 ft. Both are on Hazers which allows for some adjustment of separation.The steps in fine tuning (hopefully) consists of plugging the default values into YO7.5. I emphasize the gain, about 75% and optimize for a single yagi on a specific frequency in the middle of the band of interest. My problem here is that in my YO program when I enter the stacked pair it allows dimensions for only one data set. In other words I can not use different data for top and bottom antennas. Consequently I generally run for a single antenna at 75 ft. I then plug these figures into Eznec and where I can vary the dimensions for each antenna and vary the data for predicted max gain. These numbers are entered into the control box and then tested for acceptable SWR. If SWR looks too high I will adjust the driven elements first for acceptable SWR. If there is only a small physical difference I am done. If the difference is greater I adjust the passive elements but attempt to remain within the same proportions. In no case (all frequencies) are the dimensions for the upper and lower antennas the same. This indicates to me that there are environmental differences between the two antennas although I do attempt to make them the same within my control, i.e. equal cable lengths, etc. My SWR usually runs less than 1.5:1 for each antenna or the pair in phase. I wish I had a method for knowing what I am accomplishing other than a subjective feeling and how I come out in a pileup. I am wide open to ideas. I think it is a distinct advantage to be able to tune each each antenna's dimensions remotely.


Frustrated with dial-up? Get high-speed for as low as $26.95. (Prices may vary by service area.)


See: for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • [TowerTalk] Re: Stacked StepIrs, Howard Klein <=