Going Back to School

Last year I worked with my manager and created some lofty goals for the fiscal year which ends in March. One of those goals included getting a specific certification for a product I use on a daily basis. I figured it would be a slam-dunk to take a test and pass it. Then I put off doing anything about the certification until the last quarter of the year (January through March). Now it is time to get serious about accomplishing this goal.

I have never put much stock in professional certifications for myself. Often times it is a matter of someone being able to study for a bit and then having good test-taking skills. I don't know why I felt the need to add a certification at this point in my career. Perhaps it is something new that I haven't tried before. In any event I have spent my own money to get access to a study guide for the test.

The process for my professional certification seems very familiar to when I studied to get my amateur radio or ham license. I purchased a study guide, read through it, practiced with some sample tests, and paid money to take an exam. Today I purchased the study guide for a whopping $20. While my ham license study materials came in a physical book, the professional certification guide is 100% online. That is fine for me as I plan to study during work hours and will be in front of my computer.

I did a bit of studying today and then jumped into a sample test of 60 questions. The real one will contain 100 questions but this one gave me a good sampling of what to expect. I found that my day-to-day knowledge ensured I got 60% of the questions correct. The questions that caused the most problems are the ones with multiple answers. Instead of having a single correct answer you have to select all options that answer the question. On my first run through the test, I managed a 90%. I only need a 75% to achieve my certification but there are 17 more example tests to try.

Part of the problem with learning new things is quickly becoming bored. I am always posting about how we learn by doing things. What I need to do is take the new information and try to apply it in my day-to-day work. That will cement the knowledge and help make the test that much easier to pass when I sign up for it in the next month or so. We'll see how I do. 

Bandwidth Explained

Lately I have doing a lot of studying about ham radio in my spare time. I get a monthly magazine from the American Radio Relay League or ARRL called QST and there are a lot of concepts I don't understand as I read articles. Rather than continuing to read and glossing over the complex subjects, I am trying to understand them more. This has me thinking about bandwidth and what it actually means.

We use bandwidth in our casual conversations with phrases like, "I don't have the bandwidth to work on that right now." That generally means that you are doing so much you don't have room in your schedule to do anything else or that the task consumes more time than you have free. We also talk about bandwidth for WiFi and how much data we can stream to our devices like smartphones, TV's, and computers. Here is a quick history lesson of what that all means and why it relates to ham radio.

When we first discovered that we could send messages over the air without having to use wires or connections, we found that we needed a carrier frequency for the message. At first, we sent messages using Morse code which uses short (dot) and long (dash) pulses of energy to convey a message. To do so, you might use 14.025 MHz as your carrier frequency with the bandwidth of your message only being a hundred Hz wide. What that means is that if someone else tries to send a message at a frequency too close to 14.025 MHz, say at 14.0251, the messages might interfere with each other. To fix this you would spread the carrier frequencies further apart. Perhaps you might use 14.026 MHz instead.

Now not everyone knows Morse code and so we learned how to encode voice messages in those same radio frequencies. We started with amplitude modulation or AM and later developed frequency modulation or FM. Anyone who has spent much time with a radio knows FM has higher quality sound than AM and so most of our music listening stations are on FM. The FCC has limited AM radio stations to a total bandwidth of 10 kHz. That means if you still use a carrier frequency of 14.025 MHz, your signal will fall in the 14.020 and 14.030 MHz range as AM splits the signal equally on either side of the carrier frequency (5 kHz below and 5 kHz above). In contrast FM signals are 200 kHz or almost 20 times wider than AM signals. It is no wonder that FM signals are higher quality than AM as you can fit more information in that space. It also means that FM radio stations have to space out their carrier signals much further than AM stations. By contrast, FM ham radio signals are only 16 kHz wide as they only need to transmit voice and not music.

Now lets tie this all together with how we think of bandwidth of our Internet links at home. When signing up for home Internet service, vendors like to use terms like 10 mega-bits per second (Mbps) or 1 gigabit per second (Gbps). With 10 Mbps it means you will be able to download 10 million bits every second. 1 Gbps is much better as it is 100 times more data in the same second at 1 billion bits every second. Now remember that there are 8 bits for every byte or character in a file so if you have a 10 mega-byte file, it won't take a single second to download it at 10 Mbps, the fastest you can download it would be in 8 seconds but even that is not true. Networks use parity and error correction bits to ensure you get the data correctly. While you are paying for 10 Mbps speeds, you are really only seeing about half that because of how the network works.

So how do kHz and Mbps relate? There is a bit of math that would make this post really long and confusing, not to mention boring. Suffice it to say that when you are talking about radio signals, you generally use kHz and when you talk about data, you use Mbps or Gbps. It all translates down to how wide the radio (in the case of WiFi) or network (in the case of wired connections) signal is needed to provide the information you are trying to receive.

Dates on Websites

Earlier this week I had a neighbor call me asking about getting his amateur or ham radio license. I explained the 3 levels of licenses and privileges associated with each. I then pointed him at some study resources as getting a license requires passing a test. Next he wanted to know where he could go to take a test. I did a quick Internet search only to find significantly outdated information. When I got my license over a decade ago, you could reliably count on a test being administered on the last Tuesday of each month at a local emergency operations center or EOC. COVID must have put an end to that and the latest information I could find seemed woefully out of date.

This underscored the importance of making sure dates on a website being updated regularly. You may have a website that advertises an event in the seemingly distant future. You send people to the site to provide information about the event as that saves you from having to say the same thing over and over. The event comes and goes but what happens to the website? If it is still up after the event, people get confused. It might be easiest to update the page letting everyone know about the success of the event. Then the site can continue to exist in digital perpetuity.

My preference for dates on websites is to store events in a database and populate the website from it. Then if there are no longer any future events, you have a message that says something along the lines of, "No events are currently planned." It is also fairly easy to add new events to the database and you don't have to worry about deleting old ones as the database logic should not show past events on an upcoming events page.

I continued searching for my neighbor and eventually found an upcoming exam session in March. That seems to be a long time away but it will be March in no time at all. That also gives him plenty of time to study.

Carefully Balancing Battery Power

Every week I participate in at least one emergency amateur radio (ham) net. My Sunday evening net usually includes a training item to help us keep our ham radio skills sharp. Our most common topic is making sure we keep radio batteries charged and always have spares. This comes up so much because someone will start talking and then drop off the air with the primary cause being a dead battery. The guilty party will sheepishly rejoin the group and admit to what we already knew: no power.

This evening I find myself nursing the battery life on one of my two mobile phones. I am at the airport waiting to catch my weekly flight from San Francisco to Salt Lake City. While taking the shuttle bus from my office to the airport, I have been listening to music on my phone. I used my work phone as it is the one paired with my wireless headphones.

For the flight home I plan to watch a movie. Once again I will be using my work phone as it has a larger screen than my personal phone. I just looked at my power meter and I am burning through my battery rather quickly. I decided to turn off my music to help conserve power so I have more than enough to watch a movie on the plane. On my flight there are USB port at each seat to charge electronic devices. Unfortunately I don't carry a charging cable with me for my work phone. I may just want to get a spare for this occasion. Then I won't have to work so carefully to balance battery power.

Old and New Music Players

I spent a good part of my Saturday working on my wife's Jeep. It is a fairly new vehicle and so it didn't need any repairs. Instead I installed an amateur radio transceiver and antenna. We will be helping with the Salt Flats 100 ultra marathon at the end of the month and the radio will help us communicate with race officials as we drive to the furthest reaches of the race course.

I rarely have a lot of time on Saturdays and this past weekend was no exception. Fortunately I had the ability to multi-task while working on the car. A local radio station had a 2-hour audio program I wanted to listen to and so I did while installing the transceiver. At first I listened to the the Jeep's radio. That went well until all of the neighbor kids started making a lot of noise on the street right in front of my house. They got so loud I couldn't hear my program. It's not like I could tell the kids to go somewhere else or make less noise. After all, they were using their outside voices outside.

I thought about my predicament and realized I had an old portable music player. Not an old MP3 player, but an old tape player complete with AM/FM radio. We used to call them Walkmans even though they might be from someone other than Sony. I lost the foam-padded earphones along time ago and so I rummaged through a junk drawer for a pair of ear-buds and headed back out to complete my work.

This got me thinking about the evolution of personal music players and how far we have come since the revolutionary transistor radios that now seem so archaic. Interestingly enough, my Android phone actually has an FM radio app that would have also worked. I just didn't think of it first.

Software Define Radios

I have found my new favorite website. It is www.websdr.org and allows anyone with a Java and Javascript enabled browser to tune into a personal ham radio. You don't have to have an FCC license to use it because you are only allowed to listen and not transmit. However for someone interested in learning about amateur radio, it is a great tool.

The technology that allows each user to individually tune the radio is a software defined radio (SDR). That means that there is an antenna connected to an analog-to-digital converter. The converter listens to the entire frequency band and the user uses software to focus in on a small section of that band. Otherwise it would be impossible to listen to all of conversations at once.

One nice thing about SDRs is that you can create a waterfall display. That makes it really easy to see where others are talking and tune in. On a conventional radio, you are stuck tuning yourself or using an automated scan. It is cumbersome and noisy, not to mention it takes forever to find anyone having a conversation.

When I came across the website, I thought the waterfall display required expensive radio equipment that I couldn't afford. Then I looked into one of the sites and saw that radio receivers are only $20. Now that is really amazing. I may have to get one.

Ham Radio License

On Tuesday evening I went with my youngest son Nathan to take my Ham radio test. We both passed the technician portion and I also passed the general. That means we are both licensed Ham radio operators.

The FCC currently has three levels of licenses for amateur or Ham radio: Technician, General, and Amateur Extra. The first level is Technician and allows you to get your proverbial feet wet. The next is general and opens up several more frequency levels. Amateur Extra opens up all of the frequencies set aside for Ham radio.

The tests are fairly easy if you study the correct material. When you are done taking one test, the administrators hand you the next level test that you can take without paying any additional fees. If you pass all three, you can save yourself some money. The problem is that there is a lot to learn. I will probably study for the next two months and try to take the "Extra" test at the end of January.

My son and I came home and were very pleased that we both passed the tests. All we needed to do was wait for the FCC to enter our information in their database and assign us call signs. The government is not known for being efficient and with the Thanksgiving weekend, I didn't think we would see our call signs until next week. Even though we have passed our tests and have a radio, we can't transmit anything until our names and call signs show up in the FCC database.

Wednesday afternoon I felt optimistic and logged onto the FCC website and did a search for my name to see if my call sign was available. It wasn't. I did a bit more work and spent some time with the family. Before going to bed, I thought I would give it one more shot. Rather than searching for my name, I searched using my FCC Registration Number (FRN) that I signed up for several weeks ago. Surprisingly, I found my license and call sign properly recorded. I was amazed.

Next I had to find my son's information. I tried doing a look up on his name but didn't find his record. Next I did a look up on our zip code and last name. There it was located with mine.

Before the Internet became a household utility, it would take weeks to process Ham radio licenses. It took my son and I less than 30 hours to get our licenses and be able to start using our radio. I think that is awesome and an example of one huge that the Internet has provided for our day-to-day lives.