#Cantenna calculator inches full#
Since my QCX-mini is 40 meters, a full sized vertical, being approximately 33 feet high, is a bit impractical.
#Cantenna calculator inches portable#
My personal preference for portable antennas is to use vertical antennas as opposed to a dipole or other horizontally based antenna. Since my QCX-mini is the 40 meter version, I obviously needed an antenna for it.
On this trip I wanted to hike up to the summits of various mountains that are in various national parks. Recently I went on vacation to Virginia and wanted to do some POTA activations using my new QCX-mini transceiver. Lesson learned, wind more wire on to the coil than calculated. In the photo on the next page you can see at the top of the last turn I added more wire. As it turned out, I needed more inductance. Initially I built the loading coil with the calculated number of turns. If you have a different gage wire, put that in the coil shortened vertical antenna calculator instead. I used the coil shortened vertical antenna calculator based on where the coil is to be located in the above diagram and came up with a total number of turns of 33 with a tap at 13 turns from the top of the coil. I cut the Sink Tailpiece 3 1/2 inches long, but 2 1/2″ would have worked just fine. I am assuming that is a typical outside diameter. The outside diameter of my overflow tube is 1.5 inches. A toilet overflow tube is much thinner and lighter and works just fine. My main concern here was to put less stress on the wire that is the vertical part of the antenna. My reasoning is this, typically people use standard PVC pipe for the coil form, which is fine, but the wall thickness of the pipe seems unnecessarily thick for my application. Your mileage may vary, but this is what I ended up with.įor the loading coil form I decided to use an In Sink Tailpiece. The diagram below are my final dimensions.
My guess is that I am using only two 1/8 wave radials. Tuning this antenna for all 3 bands seemed trickier than normal. Again, I went over to the coil shortened vertical antenna calculator page which gave me my starting points for the loading coil.
Since this was going to be for 3 bands, I wanted the loading coil low enough so that I could easily make a band change without lowering the vertical. Since I already had a 20 foot collapsible fishing pole for my 40 meter shortened vertical, that is what I used for this multiband antenna. Granted at reduced efficiency, but I figured it was worth a shot. In doing some internet searches I discovered that it is possible to use radials that are 1/8 wavelength long - Yeah it sounds crazy to me too, but if its true, then it would greatly help the radial deployment issue on 40 meters. Which makes it more difficult to deploy the radials when in a heavily wooded POTA activation. On 40 meters, they are approximately 33 feet long. One problem I had with the original 40 meter vertical antenna, was that I used two 1/4 wave radials, which conventional wisdom says you should use with vertical antennas. This particular vertical antenna build is based on my original Shortened 40 Meter Vertical but with the addition of being able to short the loading coil at the proper tap point for resonance on the 30 and 20 meter bands. This meant I needed to build a portable shortened vertical for these bands. Since my original post about my first QCX-mini QRP transceiver, I now have additional QCX-mini’s that allow me to work my POTA QRP activations on 40, 30, and 20 meters. There is something exciting doing a POTA activation where you hike in with all your gear in a pack and activating a park running QRP power.
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