A Carbon Fiber Mast Vertical on the 20 Meter Ham Radio Band

Carbon-fiber masts don’t have to be the villain. For Straight Key Month I ran a quarter-wave 20-meter vertical two ways—first with 12-gauge wire taped to the outside of a Goture carbon-fiber mast, then with 18-gauge magnet wire laced inside the mast. Result: both versions delivered S9 into Utah from downtown San Francisco, and the internal-wire build was far stealthier for city operating.

I finally got to do a long term—a few hours—test of the TouCans and a Stick vertical antenna with magnet wire on the inside this week! The interior magnet wire setup worked just as well as the same antenna rigged with 12 gauge wire taped to the outside of the carbon fiber mast did. The rig was S9 into the Utah SDR that morning.

Here's a look at the antenna setup and results. There are more text details below the video..

Construction

To construct the antenna I removed the brass bottom of the carbon mast, removed the upermost segment, and then inserted 18 guague magnet wire through the bottom and out the hole at the top of the now tallest mast segment. I wrapped the wire around the top of that segment five times to secure it, and then extended the carbon fiber mast segment by segment, feeding magnet wire as I went. I cut the magnet wire off at an approximately resonant length for 14057.4 kHz, and then mounted the antenna to the back window of the house exactly as I had for the previous wire-on-the-outside version.

I'm looking forward to getting more use out of this because it makes the antenna even less noticeable in an urban environment and it nicely demonstrates that carbon fiber masts can be used in some specific antenna systems.

To demostrate what I mean when I say the antenna is less noticeable, here's the antenna using internally laced magent wire

Goture carbon-fiber telescoping mast extended; internal magnet wire build is invisible against clear sky.

and here's the antenna in the same location with external wire. More details in this video.

External-wire version: green radiator taped to carbon-fiber mast beside house wall; ‘SKCC Straight Key Month Home QTH Setup’ title.

(airplane on right side of image not included)

One last picture in case you're not a peruser of videos. This is the entry point of the magnet wire to the interior of the mast. It's threaded all the way to the top from here.

Close-up of magnet wire emerging near mast base with tape; insulation scraped at end for radio connection.

As far as constructicon notes go, there's ont thing that might not be obvious from the pictures and video. Magnet wire is insulated. That's why I wasn't particularly worried about it contacting the mast. I removed the insulation—by scraping it off with a hobby knife—from the end of the wire I connected to the rig.

The two Arizona QSOs made with the internal wire antenna are shown below. The QSO to Georgia was made with the external wire antenna two hours before when band conditions were favorable to getting out that far.

Map showing QSO paths: San Francisco → Arizona (internal wire) and earlier San Francisco → Georgia (external wire).

I made all three of the contacts operating as K3Y/6 for the SKCC straight key month event.

This post walks through the internal-wire build (how the magnet wire is fed, secured, and trimmed), compares it to the external-wire version, and shows three QSOs (AZ ×2 on the internal, GA on the external) with a route map. If you’re curious about carbon-fiber “compatibility,” this is a practical data point: with the right geometry and counterpoise, it works. Try it: bookmark this guide, share it with a friend who thinks CF masts are verboten near antenna elements, and drop a comment with your own results or questions about tuning and counterpoise placement.

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There's an assymetry to the form of the two Maxwell's equations shown in picture 1. While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero. This is typically explained in the following way. While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare. That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2]. Cabrera was utilizing a loop type of magnetic monopole detector. Its operation is in...

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:...

Copasetic Flow

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