Category Archives: Antennas

Articles about Antennas, Feedlines, Towers and related equipment. Fixed, Portable and Mobile Antenna Articles are included.

Radio Signals don’t Travel in Straight Lines by Onno VK6FLAB

Reposted by Layne, AE1N

The other day a friend of mine asked a really silly question. How come when I point my YAGI at a direction for a station using the great circle, the signal is there but weak, but when I point it in a different direction, say 20 degrees away from the great circle, the signal improves?   Being a good little Amateur, I responded with the logical explanation. Well, two things come to mind, one being that you’re not pointing where you think you’re pointing, that is, North on your antenna isn’t North in reality, so when you point at the other station, it’s not actually where you’re pointing, and when you adjust, the antenna ends up in the correct direction.

Another explanation I came up with is that the pattern of their YAGI isn’t what they expect. There might be local factors that influence the pattern, putting weird distortions into their foot-print and making for “interesting” nulls where there should be a signal, and vice-versa. That, in turn, started a whole conversation about directions and where stations are.

Leaving aside the difference between long-path and short-path, which I should probably talk about at some point, an antenna should get a signal from the direction in which you point it, right?   So, what if I told you that the antenna was, in fact, pointing correctly and there were no distortions in the antenna pattern, what then?

Turns out that the Ionosphere isn’t uniform – who’d have predicted that – in case you’re wondering, that’s a joke – the Ionosphere isn’t uniform, it takes in many and varied influences, from the earth’s magnetic field to heating by the sun, to solar storms, coronal mass ejections, and any number of factors that we as a species are only just beginning to discover.   If you imagine for a moment a radio-wave coming up from your antenna, bouncing against the Ionosphere, back to earth, then bouncing back up, then doing the same thing again, you’ll quickly understand that because the Ionosphere is variable, the height and angles at which this bouncing is occurring varies along the path.

But here’s a shocker, who said that the signal had to bounce up and down vertically, what if the same variability of the Ionosphere height caused a signal to bounce in some other weird direction, like at an angle, or sideways. Would the path of the signal from your station to the other end follow a great circle line?   Turns out that this silly question wasn’t silly at all and I learned something unexpected, my radio signal isn’t a straight line, something which I confess, did come as a surprise, but now, looking back, seems pretty obvious.   I love silly questions, they often turn into an opportunity to learn.

Onno VK6FLAB

Member Spotlight – B. Scott Andersen, NE1RD

NE1RD on Mt. Wachusett

Bio of B. Scott Andersen, NE1RD

I got my start in ham radio not long ago. In 2002, after years of encouragement from a good friend, I finally looked into the hobby. “You’ll love it,” my friend said. “It’s right up your alley.” I confess I was skeptical, and even a little uncomfortable watching him make a simple call on a 2m radio he had in his car. “Go ahead and talk,” he said. I was well outside my comfort zone.

I’ve tried to remember those feelings as I show new people our world. It can seem strange, and aspects of it still seem strange, even after all these years. “It isn’t just one hobby,” my friend admitted. “It’s 99 different hobbies. You just pick the ones that interest you.”

I have taken his advice, and now I’m involved in some of the ones that most intrigued me. Not long after being licensed, I entered my first contest. It was October of 2002, the sunspots were still active, and I worked over three hundred stations in just a few hours. I was completely hooked on contesting! A lot of the things that made me nervous in the car that day were absent here. There were no long conversations; they just wanted my exchange (5905), and on they went!

The thing that really captured my attention, though, was a DVD of a DXpedition run by the Microlite Penguin team and their trip to South Sandwich Island and Southern Thule. These guys were amazing! Small radios, lightweight gear, well-conceived but modest antennas, and they worked the world. This was something I wanted to do.

So, in the next few years, I spent most of my free time thinking about ham radio, and lightweight DXpeditioning in particular. Contesting just helped me increase my DXCC totals, and hone my skills. The culmination of all that thinking was captured in my blog “The 100 Pound DXpedition.” You can get a PDF of all these brief articles from a link on my website www.bsandersen.com

As part of this DXpeditioning interest, I also spent a great deal of time thinking about antennas, and portable antennas in particular. My book “Buddipole in the Field” was the result of some of this work. You can get the free PDF from the Buddipole User Group on Yahoo!, or from a link on my website. The Buddipole has provided a good platform for many of my experiments, and DXpeditions.

I’ve always been a nerd, interested in electronics, physics, mathematics, and the like. Ham radio has provided me a way to transition from the abstract to the concrete. It is one thing to think about radio theory. It is another to build a working radio. I’ve been building kits since the 1970’s, but ham radio has given me many new opportunities. I’m particularly fond of Elecraft kits having built two K2s, three K1s, and two KX1s. They are all fabulous radios, and building them was deeply satisfying.

I am still working, so ham radio sometimes takes a backseat to my responsibilities, but it is never far from my mind. I’ve also learned just a little patience through all this. Building up a country list for DXCC, and chasing various radio awards must be done over time (usually years) and it has paid off. I now have 8-band DXCC, WAS in both Massachusetts and New Hampshire, ARRL Challenge, and various CQ WPX awards. They look great on my wall and are a reminder that anything worthwhile requires both hard work and patience.

After all this time, I’m still very much a student of the hobby. I’m shameless about asking questions and always try to take advantage of any opportunity to see and try new things. I can only hope that this passion continues through the coming years. It has been a joy for this first fifteen, certainly!

Tower Climbing Demo and Open House at AB1OC/AB1QB

Several folks have suggested that it would be interesting to see a tower climbing demonstration. It turns out that we need to climb our tower to do some routine maintenance before winter comes. This seems like a good opportunity for folks who are interested in learning how to climb a tower and work on it safely.

A View From Our Tower
A View From Our Tower as Anita, AB1QB Looks On

Ever wonder what’s involved in safely climbing and working on an Amateur Radio tower? Here’s your chance. On Sunday, October 15th at 1 pm we will be holding an open house and tower climbing demonstration at our station.

Climbing Safety Gear
Climbing Safety Gear

We have two sets of climbing safety gear and we’ll provide the opportunity for those who want to try it on to do so. I am going to climb our tower to the 45-foot level to do some maintenance on our weather station. Anita and I will be explaining how to safely climb and work on an Amateur Radio tower.

Invitation to Operate Our Station

AB1OC-AB1QB Shack
AB1OC-AB1QB Shack

We will also provide an opportunity for folks to get on the air at our station and make some contacts as part of our open house. Our station will be configured for you to try SSB Phone, CW, and digital modes including the new FT8 mode. You can try any or all of these modes. We’ll be QRV on all bands from 160m – 70 cm. Power levels will be from QRP up to the legal limit.

We hope that our club members and friends will join us for our open house. It should be fun!

Fred, AB1OC