Wednesday, May 29, 2013

Earth Moon Earth

One of the things that has always interested me is doing an Earth Moon Earth contact. I remember trying to listen for my own echo by pointing the direction antenna from my school at the moon and bouncing an FM voice signal off of it (It takes seconds for the light path to connect back up, thus it is common to hear your own echos off of the moon). I wasn't successful.

An EME contact, simply put, is one where you use the moon to bounce signal off of and talk to someone else on the ground. This is often considered the pinnacle of VHF communications, and can in fact allow for worldwide communication, but it can be a bit tricky to perform. I am going to borrow some information from my elmer in this area, Paul, K4MSG, and specifically his article entitled "EME on a budget". This will include some of my own research on the subject as well.

Saturday, May 25, 2013

Propagation on Mars

While browsing the blogosphere recently, I came across a blog post that asked a really interesting question. What would propagation be like on Mars? That caused me to do some serious thinking, and in doing so, I've come up with how I think it might work. I am not an expert in Mars, nor an expert in propagation, but I do know something about Mars and something about Propagation. This post is intended to study how it might work, but not be an actual journal quality paper or anything like that.

In my explanation of this, I will draw on articles from Tim Mooney, Wikipedia, Window to the Universe, the European Space Agency, NASA, and Arnauld Valeille. This represents the best information on the subject I could reasonably easily obtain, however, the MAVEN mission coming up in 2014 will provide more information about the atmosphere of Mars.

Wednesday, May 22, 2013

Lesson 10- Interference with Nearby Electronics

When I first started playing with my HF radio, I noticed something strange. When I talked on 20m, I could hear sound coming out of a set of near by computer speakers. I haven't extensively studied it out, but I believe that the speakers are poorly shielded, and actually acting as a poor radio receiver. Similarly, I have had computer speakers in the past that amplified AM Radio stations in the area. In this lesson, I will better familiarize you with the source of such interference, and what you need to do as a ham radio operator to mitigate it. I should state up front, don't take any of this as legal advice.

Saturday, May 18, 2013

Expanded Phoenetic Alphabet Chart

 In my time on the air, I've noticed that the standard phonetic alphabet isn't always used. In fact, there are several different versions which are used used, depending on whom you are talking with. I was given this chart by K3US, and I am posting this, with his permission. I hope to keep this up to date, please feel free to add a comment to the post if you see any other abbreviations commonly in use.

Wednesday, May 15, 2013

Lesson 9- Setting up your First Amateur Station

So, you have your Amateur Radio License, and are looking to buy your first Amateur Radio to get started. What exactly do you need to get? In addition, what are some upgrades you might be able to get to do more with your station than you otherwise could do? In this lesson, I will discuss what an Amateur Station requires at a minimum, what some common upgrades are, and what some of the less common upgrades are that a person can do with an Amateur Station.

Saturday, May 11, 2013

Amateur Satellite Contacts

The thing that brought me in to Ham Radio in the beginning was satellite contacts. I was a student at a university building an amateur satellite. We operated on the Amateur Bands. In order to operate, one had to have an amateur license. While we were at it, one of the most common things we did was to talk to other amateur satellites, to practice tracking satellites in frequency and location. Thus began my first period to study to take the technician license exam.

Wednesday, May 8, 2013

Lesson 8- VHF, UHF, HF, What's the difference?

Radio waves are grouped in general by powers of 10. There are 4 key radio bands, UHF, VHF, HF, and MF, within Amateur Radio that have very different characteristics, which I will explain in this post, along with some of their strengths and weaknesses. While there are bands even higher frequency than UHF, they aren't commonly used by Amateurs, and so I won't talk here about them.

Ultra High Frequency (UHF) - 300 MHz- 3000 MHz- This band is the highest frequency band commonly used in Amateur Radio. It covers the 70cm, 33cm, 23cm, and 13cm bands. Of these, the most common by far is the 70cm, but 33cm, 23cm, and 13cm also have their following. UHF tends to penetrate buildings better than VHF, due to it's shorter wavelength which penetrates better. UHF is almost exclusively a line of site communication, while it will penetrate objects, it does not penetrate Earth, nor get reflected by the Atmosphere. It tends to be absorbed by moisture, and thus is affected by leaves significantly. This band is also home to many commonly used devices, such as WiFi, Coordless Phones, and other household items. Much analog TV transmission occurred on UHF. Commonly used for Walkie Talkies as well, due to the short size of the antennas required to make them work.

Very High Frequency (VHF) 30 MHz- 300 MHz- This band is very popular for Amateur Radio use, including the 6m, 2m, and 1.25m. Of these, the 2m is the most popular, but 6m has it's place. These frequencies commonly can talk beyond line of site, although not significantly beyond typically. The larger wavelengths start to exhibit the propagation characteristics such as ionosphere reflection, especially Sporadic E Propagation. VHF penetrates trees relatively well, but is mostly a line of site band as well. It is also known for FM broadcast radio, and is still used today for such purposes. I have made contacts as far as 70 miles or so away using VHF waves.

High Frequency (HF) 3MHz-30 MHz- This band is well known for it's propagation throughout the world. These waves actually are reflected off of the Ionosphere, producing a phenomena known as Skywave Propogation. Frequencies in this region include every Amateur Band from 10m-80m, I won't bother to list them all. It also includes CB radio, which allows for unlicensed communication at comparatively low power. I don't have a lot of experience yet, but I have heard conversations as far as half way across the United States in my very brief time playing with it, but I know people regularly talk across the world.

Medium Frequency (MF)- 300 kHz- 3 MHz- This only contains one Amateur Band, the 160m band. The primary means of communication with this band is Ground Wave Propagation, which has a fairly limited range. In general, the higher bands do well for communicating across a local area, while the higher bands do better for communication across the world. It should be noted that the first trans Atlantic communication via radio waves was done by Amateurs using MF. Commercial AM Broadcasting is done in this band.

Saturday, May 4, 2013

First HF setup and contacts

I've finally pieced together my  first HF rig, and make my first contacts with it! I've been able to hear people from as far away as Japan, but I haven't had a whole lot of success transmitting yet. Still, I'm getting better with things, and I hope that a bit more practice will leave me to doing great! Without further ado, my setup, as well as my first DX contacts!

Wednesday, May 1, 2013

Lesson 7- Atmospheric Propogation

There is no subject that I have more difficulty understanding than Propagation in terms of Amateur Radio. I've been trying to explain it to a Ham-in-training, but I've had some difficulty, so I'm going to take the time to learn about it and explain it to you all.