Tag Archives: HF

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

Remote Control Ham Station Enhancements

As explained in a previous article, we have been working on enhancing our Remote Control Ham Station system. The upgrades include additional remote client options, better remote networking via the Internet, and better integration with our microHAM system.

Source: Remote Operating Enhancements | Our HAM Station

As part of the fall upgrade plans at our station, we have completed quite a few enhancements to the Remote Operating Gateway and associated client devices in our station. The upgrades include:

You can read more on our Stationproject Blog about our Remote Control Ham Station Enhancements.

We try to do some station upgrades in the fall of each year to maximize our operating fun during the winter months. We always welcome members who want to join in on our projects as a means to learn about station building. More to come as we make progress with our planned projects.

Special thanks to Dave, K1DLM who has helped us with ideas for several aspects of this project.

Fred, AB1OC

Plans for Enhancing Our Ham Station This Fall

Source: Plans for 2017 Station Upgrades – Radio, Shared Amplifier, and Remote Op Enhancements

We are planning a number of enhancements at our Ham Station this fall. Our plans include:

We try to do some station upgrades in the fall of each year to maximize our operating fun during the winter months. We are at the design stage on these projects and I wanted to share some information about what we are planning from our Stationproject Blog.  We always welcome members who want to join in on our projects as a means to learn about station building. More to come as we make progress with these projects.

Special thanks to Dave, K1DLM who has helped us with ideas for several aspects of this project.

Fred, AB1OC

Amazing DX Opening on the 12m Band

Today proved out some simple, tried and true advice for me – it pays to take some time and tune through the bands. I just got a Maestro Remote Control Device for our FlexRadio SDR and I took a break around lunchtime to tune through the higher HF bands to see what I could hear. We use a Flex SDR as a Remote Operating Gateway into our station and the Maestro allows me to run our station over our home network with going down to the shack.

I am not sure why but I decided to give the 12m band a look today. When I did, I was stunned! It is about noon time and the 12m band is wide open between Africa and the US!

12m DX - XT2AW Burkina Faso
12m DX – XT2AW Burkina Faso

I worked two DX stations on 12m SSB. The first was XT2AW, Harald in Burkina Faso. Harald was working split and was not real loud but I had no trouble completing the contact with him. Excited, I tuned across 12m some more and found an old friend – Theo, ZS6TVB in South Africa. I had a very nice QSO with him. We both marveled over the propagation on the 12m band that we were experiencing. He was 57-58 here in New Hampshire!

The sunspot conditions are pretty weak (SFI 85, SN 26) to create such a good opening on 12m. I believe that we may be experiencing Transequatorial Propagation (TEP) which can provide a significant propagation enhancement on paths with traverse the equator. Anita and I experienced similar TEP propagation on 10m when we were on Bora Bora Island early in 2012 with similar solar conditions.

It just goes to show that it pays to tune the upper HF bands. Especially on days when “they are not open”. Also, 10m also appears to be open to Africa right now – I am hearing a station in Mauritania

Fred, AB1OC