This will be the first of many discussions on radials. They may get their own heading like antennas, because I really believe they are a separate discussion.
I was thinking about the Wolf River Coils (WRC) antenna and the radials that come with it. Why 3? I think it had to do with the Ventenna experiments. These experiments concluded that 3 radials were superior to 1,2,or 4. Implying 3 radials tuned for the lowest band where the way to go. How ever in the WRC FAQ, they state “3 radials are the minimum but more is better” How many more and what length? So many questions.
The Ventenna study said 3 radials 1/4 wavelength were the way to go. Well what about a variable length vertical antenna? Do we need to match each band with a set of 3 – 1/4 wave length radials? Technically since 1/4 wave is the designed length for a radial that makes perfect sense. or does it ? Shouldn’t we change the radial length to reflect 1/4 wave of the current Frequency? I suppose that makes sense also.
My own experiment with radials involved the Frankentenna. It was a tape measure vertical with the large part of the tape close to the ground and the tape extending up with the help of a pulley system. I would extend the tape to what I guessed were the amount of inches for the band. Then using a swr meter dial it in. The other part of the equation was the radials.
The radials were 12 foot tape measures, extended to their full length. I never completed the experiment, was just happy to make some contacts. What I had in mind would make one hell of a science project.
Take the longest retractable tape measure you can find. I think Stanley may have a 45 or even 50 foot in their line. Put it in a non metallic pole going the length of the tape up plus 2 feet to allow for a mounting point and a place to put the connector. As you can see on the Frankentenna page, put a plate down to connect 8 tape measures as radials.
The questions to be answered: A) Can resonance be achieved on multiple bands by maintaining a static vertical length and moving the radials? B) What is the ideal proportion of vertical height to radial length and is it a definable constant? C) What is the effect of the tape measure container, holding a coil of spring steel? D) Does the coil of of the tape measure affect the radials, if so how? E) Does the width of the tape measure affect conductivity on the radials and/or vertical? F) Can a tape measure be modeled in an antenna modeling program, and if so what does the output look like?
I became overwhelmed by the shear volume of information needing to be gathered and went on to other things. It would make a great project for a continuing science fair project or doctorial thesis.
Alas I digress, and that kids is why there is a squirrel on the page!
73 KF7SFU
David Campbell KF7SFU 