05/13/13

Repost: kb6nu.com – Tip of the Day: Add elements to make a single-band dipole a multi-band antenna

Link to Original Post

You can make a make a simple dipole antenna into a multi-band antenna by adding an additional set of elements for the band you want to operate. A couple of years ago, I added 30m elements to my 40m dipole and now it works on both 40m and 30m. The reason this works is that when operating 40m, the 30m elements present a relatively high impedance, while the 40m elements a relatively low impedance. RF current, like any kind of electrical current will take the path of least resistance.

As shown below, the 30m elements hang down below the 40m elements. If you space the elements close to one another, you may have to tweak the lengths of the elements for the best SWR. In my case, that wasn’t a problem.

fan-dipole

If two bands is good, why not four or five? Yes, you can do that. You can add as many bands as you have space and wire for.

02/13/13

Fan Dipole Project February 2013 – Update 2

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It’s Wednesday now. I made my plan for the fan dipole yesterday and today I have cut all the bands 10 through 40, expect 40 meters. I’ve got to get some help with that one from the wife cause it’s so long. Plus got to do that outside, not enough space in the apartment. You ask why I cut all the bands? Well, now I’ve decide on two fan dipoles. The first one this weekend with be 6, 10, 20 and 40 meters. Minus 6 meters I’ll use this one the most including in upcoming State QSO Parties, specifically NC QSO Party. I really want a card from NI4BK.

Plus I’ll go ahead and cut my 70.5 delta loop section as well.

02/10/13

Downtown Indianapolis from the Central Public Library

2013-02-10_13-38-52_9612013-02-10_13-38-59_5My blog isn’t all ham radio and electronics or tech. From time to time I do something “normal.” Right I’m kind of bored siting the main branch of the Indianapolis Public library, Central Downtown Branch  It’s quite large and very nice. The front portion is the original built in forever ago. As you past toward the back though there is a 6 story addition of glass and bookshelves.

If one could get out to the roof this build would be perfect to throw a few end or ever center feed antennas off. There’s ever a grass lot in front of the building  I assume historical significance, to setup a reasonable sized Field Day op. There’s 5 good sized tree for smaller antennas. Ones I think probably under 40 meters size. A little to far apart for hammocks.