Antenna Adventure

Hi again!

The end of October is almost here and with it comes winter weather, especially around these parts. A few days ago, I was told North Dakota was in a winter storm warning with 12+" of snowfall expected! Of course, I'm sure Northwest Missouri is next.

Which brings me to today's post - antennas. Currently, I am running a roughly 29' random wire antenna fed with a 9:1 unun around the ceiling of my room. It works, but we recently installed GFCI outlets in another room that trip every time I'm on a band below 15 meters. Obviously, there's too much RF for my house to contain, and the only option now is to put my antenna outside. So strap in, because this will be a thorough and long adventure! Oh, and feel free to correct me in the comments below... I'm still learning.

Throwing an antenna in a tree should be straight-forward, but unfortunately, it's not. I live in a place that is subject to lightning strikes and severe storms often, so shack (in this case, house) protection is a must! Otherwise it'll turn into a burning dumpster fire. This involves a lot of grounding, or at the very least, disconnecting your equipment when lightning is within 10 miles of your QTH. You could also go to the extreme like me and pack up all of your equipment in waterproof boxes and move to the basement, but I'm sure that would get old.

I have finally decided to do something I should have done when I got on HF - install a permanent antenna system out of doors. If you're an unfortunate soul who lives in an urbanized area like me, antennas are a mess to install and quite a pain at that. I'm confined to a space of less than 1/10 of an acre.

The Almighty End Fed Random Wire Antenna!!!

In my HF experience, I have been limited to tight spaces and tolerances, namely, the four walls I call my bedroom. The random wire has been my friend from day one, and I can say that it has gotten me FT8 and SSB QSOs from across the pond and across the states. It's not even a full-sized one either or really efficient for that matter, measuring in at about 30ish feet. I have also heard myself on SDRs hundreds and thousands of miles away.

Below are some common EFRW lengths in feet. Notice that they are not anywhere near half a wavelength of a resonant antenna. Data is taken from hamuniverse.com

29    35.5    41 (40m-10m)    58    71 (80m-10m)   84    107    119    148    203    347    407    423

Keep in mind that you may need to adjust for resonance, or in this case, non-resonance. Shorter lengths should tune up well on higher bands like 20 or 15 meters. Random wires are weird in this case - if your radiator is resonant on a specific frequency, your antenna system won't work well at all. For example, if it's cut to around 65 or 66 feet, tuning up on 40 or 20 meters will be challenging.

There are many instructions to build an end fed random wire (EFRW), but my personal favorites are the EARCHI version as well as the CaHR version. Both utilize a 9:1 unun transformer to bring impedances back to around 50 ohms. The only downside with this antenna is that it may require a tuner, but I'm sure this shouldn't be a problem to many hams. Both also have the option of adding a counterpoise, though it is not necessarily needed but it might provide better SWR and improved efficiency and less RF noise. A counterpoise will suffice for almost any setup, as long as it is a quarter-wave on the lowest band you want to work. This is a good place to start. Just like the radiator, any configuration should work.

To test your antenna length, connect the antenna system to an antenna analyzer. If the antenna is resonant on your desired bands, the SWR should be relatively low around your desired frequencies. 3:1 is negligible, but 30:1 is a different story!!! Using an antenna tuner should lower your SWR down to a perfect or near perfect level. You may need to lengthen or shorten the radiator or counterpoise element(s) depending upon your circumstances. You can also adjust your counterpoise wire length as well. A common counterpoise value is between 20 and 30 feet.

A random wire can be placed in any configuration, another way to add to it's "random" namesake. Sloper, Vee, all over the place - you name it, it should handle it. For even better performance, I'd recommend a 1:1 common mode/current choke on the input of the antenna. A few wraps of RG-58 coax around a FT-240-43 or -31 toroid should help. Random wires are known to introduce RF into the shack, and this should help suppress some of the noise. 

One other thing I should mention - if your house has GFCI/AFCI outlets, chances are that these are prone to RF interference. The ARRL has done extensive research and has found that not every manufacturer includes RF suppression in their circuitry. In fact, the ARRL helped a company fix this issue after the company received multiple complaints from, specifically, radio operators regarding their outlets tripping every time they'd key up. For me, I can't go below 15 meters or above 5 watts without tripping one of these outlets. My only choice (hopefully!!!) is to move my antenna outside so I don't start a fire in my house, albeit these outlets are supposed to protect from that.

OS Update (Again...)

In the past few weeks, I've been having issues with my HP Notebook computer running Andy's Ham Radio Linux. I keep getting screen artifacts and I have confirmed that it is not the GPU/CPU. It is running at optimal temperatures. To fix it temporarily, I have enabled "nomodeset," but this only works as a bandage repair. I have a feeling that my ISOs on the USB sticks are corrupted, so I'll more than likely need to reburn them.

As a last resort, I whipped up a Windows ISO and, to my surprise, it worked! So I guess I'm going to stick with Windows now??? Meaning I won't need to buy a Windows laptop after I'm done with my school one!!! Yay! And I now have a way to make music again too!

I'm hoping to get my hands on a Chromebook so I can port one of these Linux distros (either Mint or AHRL) to it. If I can do this, I'll use the Chromebook for portable operation and the Windows laptop for home operations. I have also enabled the use of Winlink successfully on both Windows and Linux and made an 800-mile mail exchange!

UPDATE: While imaging a Raspberry Pi, I also ran into the same imaging issue. The culprit? Cheap USB or SD Card devices. Make sure that you use quality brands (SanDisk, PNY, etc.) while burning ISO images. Generic ones will usually fail checksums, as I have found.

Conclusion

As I write this, it appears that we have reached the end of the semester, or are rather close to it. I have to say that it's been fun! The temps have officially hit below freezing but the sun still shines. I didn't get to go out to the field this year, but if we have a 50 or 60-degree day, I might see if I can make it happen and make some QSOs. I'm also leaving for Arizona once again during the Christmas holiday and I plan on heading back to Ham Radio Outlet to see if I can get my hands on something!

The trees at Northwest are absolutely beautiful this time of year. It's a sign of the changing times and season. I'm only two semesters away from graduating from Northwest with my BA and my BS degrees, and I must say that it will be hard to transition out of this period in my life. I've had so much fun being a college student and learning all I can about everything. 

Also, my attempts at learning Morse Code have proven to be somewhat effective. I could probably make a QSO at 5 wpm, but I hope to increase that later on. My Arduino practice oscillator has helped drastically with this and I'm starting to recognize the letters by dot-dash pattern thanks to the OLED display with the hard-coded Morse Code library. 

That's about it, but stay tuned as I dive in to the world of APRS!