Tuesday, March 30, 2010

Handiham World for 31 March 2010

Welcome to Handiham World!

Before we do anything else, I'd like to share last week's Midwinter Madness Hamfest with our readers. After that, we have a special edition of the Handiham World that is dedicated to operator improvement.

Midwinter Madness Hamfest Photos

Midwinter Madness Hamfest Photos - wide angle view of crowd
Our thanks to the Robbinsdale ARC for table space at Midwinter Madness, the closest Hamfest to Handiham Headquarters! Photo credit: RARC.

Pat, WA0TDA, & Matt, KA0PQW pose at the Handiham table.
Pat, WA0TDA, and Matt, KA0PQW pose in front of the Handiham table. Photo by Susan Tice.

Susan Tice and Jasper at the Handiham HQ office, getting ready for the hamfest.
Susan Tice and Jasper get ready for the hamfest by helping to pack the booth equipment at Handiham Headquarters. Asked if it was a tough job, Jasper said, "ruff". WA0TDA photo.

Bob, W0LAW, ARRL MN Traffic Manager at the ARRL table right next to us.
Bob, W0LAW, ARRL Minnesota Traffic Manager, mugs it for the camera at the ARRL booth, right next to the Handiham booth. WA0TDA photo.

Now, to our special feature: Communicating with other hams: It’s all about exchanging information.

Okay, I've had it with bad communications and bad communicators. It's time to teach some "elementary" ham radio. In a special three-part series, we are going back to our Technician Class studies to review some communications basics. To help us, we are taking the information from my teaching notes - the very same notes I use to teach in my own local club's Technician course. We can all do with some reminders of what constitutes the basics of amateur radio communication.

Ready to review the basics? Good! Let's get started.

The basics

Start with callsigns: My callsign is WA0TDA.

Every other station has one, so you will use both of them to initiate a contact:

“W0ZSW, this is WA0TDA”.


Use your callsign.

Speak clearly & slowly.

Use phonetics when conditions make hearing difficult.

Position your microphone correctly.

Repeat (or ask for a repeat) of the information as necessary.

When you are done talking… (Read more on the Handiham website, or listen to the audio podcast.)

Wednesday, March 24, 2010

Handiham World for 24 March 2010

Welcome to Handiham World!

drawing of a tree with branches

Recently we talked a bit about how to put some logic into your decision making when you are comparing equipment or antenna performance. The topic was the venerable A-B test, using a two-way switch that could be connect first one antenna, then another. The idea behind this kind of testing is to eliminate as many variables as possible so that we are really just comparing the two things that we want to compare. After all, using separate transceivers (each one connected to its own antenna) puts into play the extra variable of radio performance when what we really want to do is compare one antenna to another one. It makes much more sense to use a single radio and an A-B switch with the common side connected to a single radio and the switched outputs each connected to separate antennas.

Now I would like to introduce you to another related concept to help you work your way through troubleshooting. It is called a "decision tree". A decision tree gets its name because it branches out much like a tree. From the main trunk, let's say there are two large branches. From each of those branches there are two more, and so on. At the base of the tree it is easy to see just the trunk, but high up in the air atop the tree there are thousands of branches. The concept of the branching tree can help us to solve problems with our electronic equipment. Decisions must be made logically and empirically, beginning at one point where the symptom of the problem presents itself and is easy to see, much like the trunk of the tree. Sometimes there may be many, many possible causes for that very same symptom -- all of these possible causes are represented by the many branches at the top of the tree. If we look at the top of the tree, we will see a confusing collection of branches, or possible causes to our problem. The idea of the decision tree is to start at the trunk with the most obvious symptom and follow the branches outward and upward until we arrive at the single twig at the top of the tree that is the cause of our problem.

Now, let's see how this works with a problem that most of us have encountered with our radios.

Let's say that we go down to the ham shack in the basement and turn on the HF radio. Oddly enough, nothing seems to happen; no sound comes out of the speaker. Of course with a problem like this there can be many possible causes. Putting the idea of the decision tree to work for us can save time and effort as we work our way logically toward a solution to the problem.

1. Did the radio power up?

If the answer is yes, proceed to number two.

If the answer is no, we follow this branch:

Is the power switch in the on position?

If the answer is no, turn on the power switch and your problem is solved.

If the answer is yes, you now have another branch to follow:

Is the radio getting power from the power supply?

If the answer is no, you need to follow another branch:

Is the power supply is turned on?

If the answer is no, turn on the power supply and the power is now available to the radio and you may proceed to operate normally.

If the answer is yes, you are off to the next branch:

Is the power supply plugged into a live AC outlet?

If the answer is no, you need to plug it in or find another outlet that is live, then proceed to operate normally.

If the answer is yes, you need to check the fuse or circuit breaker in the power supply and proceed along a line of determining a problem with the supply rather than the radio.

2. Is the audio gain turned up high enough to hear sound?

If the answer is no, turn up the gain and proceed to operate normally.

If the answer is yes, you are off to the next branch:

Is there any sound at all when you listen closely, such as a weak hiss?

If the answer is no, you will want to follow a line of checking external speaker connections, whether headphones have been left plugged in by mistake, and so on. Several more branches can be followed here - you get the idea.

If the answer is yes, you will want to follow several other branches that will include checking the RF gain control, the antenna connection, any tuners or other accessories in the feedline, and so on.

As you can see, a decision tree can be quite long and branching, even for a simple problem. However, the idea is to begin logically with the things that are easiest to check and most likely to be the cause of the problem. It certainly wouldn't do to immediately run outside and check the antenna if you didn't hear sound from the radio. Audio gain controls that are turned down, squelch controls that are turned up too high, RF gain controls that have been turned way down, or an antenna switch that is in the wrong position are all more likely causes of the problem. Furthermore, you wouldn't want to start working on repairing your transceiver if a circuit breaker in your house's main breaker box has tripped, causing the outlet into which your power supply is plugged to be dead. It is all about following a logical, thoughtful path in problem solving.

Believe me, this is not something that new ham radio operators -- and even some with extra class licenses -- always know how to do. Logical troubleshooting is something that can be learned by experience. Sometimes equipment repair manuals include graphical decision trees to help technicians working at the service department proceed through the diagnostic process and a logical and efficient manner. These days, software can help us make decisions as well, but I would like to see our Handiham members be as independent and self-sufficient in troubleshooting basic problems as possible. At the upcoming Minnesota radio camp we will be considering how to solve basic problems in the ham shack. Practicing this skill makes us all more independent and ultimately better operators. After all, amateur radio is a technical activity, and we should be able to do some basic troubleshooting.

For Handiham World, I'm...

Patrick Tice, wa0tda@arrl.net

Wednesday, March 17, 2010

Handiham World for 17 March 2010

Welcome to Handiham World!

Pat, WA0TDA, in green for St. Patrick's Day
Photo: Pat, WA0TDA, with microphone, sports a green T-shirt, green beads, and a green screen background for St. Patrick's Day. Hey, if Chicago can dye a river green, we can do this!

Happy St. Patrick's Day, everyone. This is the first time in my memory that the Irish holiday has fallen on the same day as our weekly newsletter and podcast, so why not just use it as an excuse for a fun way to start our weekly column?

I'm not sure if there are any special ham radio events associated with St. Patrick's Day, but I do know that there are plenty of parades and other civic events. St. Patrick's Day is always a big deal in cities like Boston, Massachusetts and St. Paul, Minnesota where there are historical Irish roots. Any time you have a parade or civic event there is an opportunity for amateur radio support in the form of communications. While I know of no amateur radio support for parade activities during today's activities here in the Twin Cities, amateur radio volunteers do support plenty of other worthwhile civic events. Marathons, bicycle races, walkathons, and other types of parades or large events that cover considerable territory are all candidates for amateur radio communications support.

These types of activities are similar in many ways to the volunteer work that amateur radio operators do in emergencies. However, there is a difference in that many of the communications in an event are much more routine and may be structured in a more informal way than communications in an emergency where a command structure is set up under very specific guidelines. In a public service event, which is what these non-emergency activities are called, your radio club may decide to participate as a group and call for volunteers. It always helps when public service communicators have some training and experience, but public service communication may be a less demanding place to get started than in emergency communications. It all depends on the event and the person in charge of communications. Some events are so large and complicated or cover so much territory or have potential for generating emergency response-style situations that they may be looking for volunteers who are more familiar with a structured incident command system. On the other hand, some events are more easily managed with semi-formal organization and communication. While good operating practice is essential for either, you may want to get your feet wet by helping with communications at one of these smaller events in the realm of public service.

Good communications basics will include knowing how to identify your station, including identification by location if that is the most efficient way to identify and it is what your group has agreed to do. This is called a tactical identification. Of course you do still have to use your FCC-issued callsign periodically as specified by Part 97 rules. A tactical identification might be something like "rest stop five". At the end of a series of transmissions and every 10 minutes you do have to use your regular callsign. There are many other things to learn about public service communications that will help you learn "on the job" as you gain experience and work toward being a capable volunteer in ARES, able to handle more demanding formal communications within an incident command structure.

In many ways, amateur radio is like other learning activities. If you were to have to learn calculus or how to speak Chinese, you would not begin with differential equations or interpretation of ancient Chinese texts. You would instead choose to begin at, well, the beginning! You would start with simple concepts and easy tasks, practicing and learning incrementally, gaining knowledge every time you study or practice. Amateur radio is a huge and complicated activity when you consider all of the different licensing classes, the many different types of technology, multiple modes of operation, and extraordinary array of on the air activities. No one expects you to get your first license and be able to do everything -- and that goes for being a public service communicator. You need to start at the beginning, perhaps volunteering at an event like a St. Patrick's Day parade. Don't forget to wear green, and a reflective vest if you are on the parade route.

For Handiham World, I'm...

Patrick Tice, wa0tda@arrl.net

Wednesday, March 10, 2010

Handiham World for 10 March 2010

Welcome to Handiham World!

All about ham radio cartoon.
Recently I had a nice visit with another operator, and what do you think we talked about?

That's right - we talked about our stations! The conversation took a turn to receiver performance, and he mentioned that one of his radios has a much more sensitive but quieter receiver than the other. I wondered how he knew that, and he said that he had performed an "A-B" test. That's what today's essay is about - not receiver performance.

When we compare two pieces of equipment, we want to know which one performs the best. How many times have you heard someone make a claim on the air for one rig's superiority over another one? Or that one antenna works better than another? Whenever I hear such claims, I wonder if they are really backed up by testing. I know that most of us will never have a test lab full of instrumentation to run tests the way they are done at the ARRL product review lab, but that doesn't mean that we have no way to perform simple, but more meaningful testing.

Imagine these situations:

Scenario 1: I have two HF antennas in my back yard. One is a vertical and one is a dipole. The dipole is connected to my Icom IC-706M2G and the vertical is connected to my Icom IC-7200. I decide to see which antenna works best for DX, so I listen on 20 meters and I hear a European on 14.060 MHz. The station is easy to copy on the vertical antenna, and the S-meter reading shows S9. I listen on the dipole and the same station on 14.060 is only S5. Do I conclude that the vertical works better?

Scenario 2: I have two HF antennas in my back yard. One is a vertical and one is a dipole. I have both of them connected to an antenna switch, so that I can switch from the vertical to the dipole by turning the antenna switch. The antenna switch is connected to my Icom IC-7200 transceiver. I start my test by listening on the vertical. I hear a station on 14.060 MHz, and the S-meter reading is S9. Then, without changing anything on the radio, I flip the antenna switch to the dipole. I now have an S-meter reading of S9 + 10 dB. I quickly change the antenna switch back to the vertical and the signal drops back down to S9 again. Changing the switch once more to the dipole brings the signal back up. Do I conclude that the dipole works better?

In both situations, I was listening on one antenna and then the other, but the results in scenario 2 were different than those in scenario 1. What could have caused the difference?

Here is a basic rule about comparing two things: You must try to eliminate as many "variables" as possible so that you are really only comparing the two things you want to compare. This is how scientists and engineers perform tests related to theoretical concepts or engineering projects. To make this as simple as possible, let's make up a very basic example. Let's say we have a family argument about which sibling is taller. One brother says that he is growing faster and is taller than his brother. Of course as a parent you can easily make the two kids stand side by side and then you can easily see which one is taller. But what if one stands on his tiptoes? Or if one wears shoes and the other is barefooted? Or if one wears a hat and the other doesn't? As a parent who needs to be fair about deciding, you will have to insist that the variables of shoes, hats, and standing flat-footed are all eliminated so that the one variable you really want to measure, which kid is tallest, will not be affected by those other things.

Getting back to our scenarios about the antennas, we see that in the first situation we are using two different antennas, which is the variable we want to test, but we are also using two different radios. The difference between one radio and the other is a variable that we are not controlling, and that could account for the results we are getting instead of the choice of antenna. Perhaps the attenuator was turned on for one radio and not for the other. Maybe the antenna tuner was not activated for one radio. It could be that the run of coax between an antenna and one of the radios was defective. Do you see all these variables?

In scenario 2, we use only one radio, and we have an "A-B" antenna switch to make it easy to change from one antenna to the other, and to do so very quickly to eliminate changing band conditions or radio settings and radio performance as variables. Furthermore, we can change the switch back and forth several times to confirm our tests. Now we have performed a more scientific test, because we have eliminated as many variables as we could, at least the easy ones, so that we could really compare just the antennas.

I am convinced that there are a lot of folks out there who are simply talking baloney when they brag about how one piece of equipment is so much better than another one. As often as not, they have never performed a real A-B test and are relying on their impressions rather than empirical evidence. Building up a habit of eliminating variables and focusing on only the thing you really want to test is at the core of successful troubleshooting when you are trying to find a problem. It is essential to making sense of how things work in ham radio, as well as in so many other parts of life.

So think to yourself, "When I test my equipment, am I really testing just one thing?"

If you can answer yes, you are well on the way to solving all of your ham radio mysteries!

For Handiham World, I'm...

Patrick Tice, wa0tda@arrl.net

Wednesday, March 03, 2010

Handiham World for 03 March 2010

Welcome to Handiham World!

SOHO solar image from 2 March 2010 showing 4 spot groups.

As we head into the longer daylight hours here in the Northern Hemisphere, band conditions will begin to favor the higher frequencies of the High-frequency (HF) spectrum and thunderstorm static and absorption will get worse with more hours of solar energy hitting the "D" layer of the ionosphere. HF radio waves are not reflected by the D layer but do lose energy as they pass through.

As explained by Wikipedia, "This is the main reason for absorption of HF radio waves, particularly at 10 MHz and below, with progressively smaller absorption as the frequency gets higher. The absorption is small at night and greatest about midday. The layer reduces greatly after sunset, a small rest remains due to galactic cosmic rays. A common example of the D layer in action is the disappearance of distant AM broadcast band stations in the daytime."

This, of course, means that amateur radio operators will have to stay up late into the night to make contacts on bands like 160 and 80 meters once the long days make those bands difficult to use for all but a few hours out of 24. That same solar energy heats the ground, causing convection and building thunderstorms that make those same bands crackle with noise all summer long. On the plus side, the conditions are still acceptable on 160 and 80, so you still have some time to collect some DX contacts. Don't wait too long though, because the days are getting longer by a few minutes each day. (Exactly how many minutes depends on your location.)

Fortunately, 20 meters is coming back to life and will improve with the upcoming season. Sunspot numbers are up. Today, we see four groups: 1045, 1051, 1052, and 1053. Higher sunspot numbers are associated with better long distance propagation conditions on the higher frequencies of the HF spectrum. 20 can be a crowded band, but soon 17, 15, 12, and 10 will open up for DX and the fun will really begin for a lot of our newly-licensed Generals. These operators have never experienced the fun of a solar maximum!

When conditions are good on 14 mHz and above, you can work great distances with low power and surprisingly simple antennas. Even that plain vanilla wire antenna that never seemed to hear much of anything on 10 meters can come to life with DX. Mobile antennas can be used to work the world. QRP, or low power operation, becomes practical for daily use. Furthermore, because the length of an antenna like a vertical or dipole is inversely proportional to the frequency at which it will be used, the return of the higher frequencies means that you can perhaps finally fit a shorter, but highly effective, antenna into limited space. A dipole for use on 3.925 mHz is around 120 feet (37m) long, whereas a dipole for use on 28.310 mHz is only about 16 and a half feet (5m). This makes balcony and attic antennas practical.

As conditions begin to pick up on the 10 meter band, Handiham members who hold Novice or Technician licenses can take advantage of SSB phone operation between 28.300 and 28.500 mHz. Since most will be Technicians whose only experience on the air will have been with 2 meter FM repeaters, it will be a fantastic change for them - and a lot of fun! Imagine not having to depend on a repeater to talk to other stations far from your own location. Imagine not having to wait for drive time to be over before you can use a repeater. Imagine being able to tune with your VFO up and down the band instead of being stuck on a single repeater frequency. Imagine making new friends around the world and collecting QSL contacts for Worked All States and DXCC.

With the additional fun comes new responsibilities. Working the HF bands is different than repeater operation in other ways that newcomers might not realize. For example, while a repeater is silent for a period of time, that means that the repeater is not in use and you can usually just throw out your callsign to look for a contact. On HF, just because you don't hear anything on a given frequency does not automatically mean that the frequency is clear. In HF operation, you may not be able to hear both sides of a QSO because of propagation conditions. If you just grab the frequency and start calling CQ, you may be informed that the frequency is already in use! On HF you have to listen even more than usual, and once you are fairly sure the frequency is probably clear, it may be prudent to ask, "Is this frequency in use?", after which you give your callsign.

Another difference between repeater operation and HF is that you can generally count on being able to complete the contact on a repeater, because the system is set up to maintain solid copy as long as both stations remain in the repeater's coverage area. On HF you can begin a QSO with excellent copy, only to find that changing band conditions suddenly cause you to lose the other station or sometimes cause other stations to "skip in" from far distances and cause QRM. Under such conditions, you have to be sure to trade essential information about yourself and your station before conditions change.

Contests are another feature of HF operation that will be new to those who have cut their teeth on repeaters. On contest weekends, the band can literally fill with stations eager to rack up points, making it either really hard to enjoy a long QSO with a friend or, to make the best of it, a fun way to make a lot of contacts and improve your operating skills. You can find out what contests are going on at any given time by visiting ARRL.org and following the "Operating Activities" link.

So to those of you who have not been on HF, let me extend a warm welcome to a whole new kind of operating. We are going to have a lot of fun in solar cycle 24!

For Handiham World, I'm...

Patrick Tice, wa0tda@arrl.net