2014 Tech study guide: schematics and components (part 1)

My study guide covers the questions in T6C and T6D of the question pool in four separate sections. Overall, the question pool committee added several questions to T6C and T6D, but in part 1 below, all of the questions and answers are the same as in the 2010 question pool…Dan

Schematic symbols is the name for standardized representations of components in an electrical wiring diagram. (T6C01) The symbols on an electrical circuit schematic diagram represent electrical components. (T6C12) The way components are interconnected is accurately represented in electrical circuit schematic diagrams. (T6C13) T1 Figure T1 is a schematic diagram of a simple circuit that turns on a lamp when a positive voltage is applied to the input. Component 1 in figure T1 is a resistor. (T6C02) Its function is to limit the input current.

Component 2 in figure T1 is a transistor. (T6C03) Its function is to switch the current through the lamp on and off. The function of component 2 in Figure T1 is to control the flow of current. (T6D10)

Component 3 in figure T1 is the lamp. (T6C04) Component 4 in figure T1 is a battery. (T6C05) This battery supplies the current that lights the lamp.

2014 Tech study guide: math for electronics

Below is the “Math for electronics” section of the 2014 edition of the No-Nonsense Technician Class License Study Guide. As always, comments welcome…Dan

When dealing with electrical parameters, such as voltage, resistance, current, and power, we use a set of prefixes to denote various orders of magnitude:

  • milli- is the prefix we use to denote 1 one-thousandth of a quantity. A milliampere, for example, is 1 one-thousandth of an ampere, or .001 A. Often, the letter m is used instead of the prefix milli-. 1 milliampere is, therefore, 1 mA.
  • micro- is the prefix we use to denote 1 millionth of a quantity. A microvolt, for example, is 1 millionth of a volt, or .000001 V. Often you will see the Greek letter mu, or μ, to denote the prefix micro-. 1 microvolt is, therefore, 1 μV.
  • pico- is the prefix we use to denote 1 trillionth of a quantity. A picovolt is 1 trillionth of a volt, or .000001 μV.
  • kilo- is the prefix we use to denote 1 thousand of a quantity. A kilovolt, for example, is 1000 volts. Often, the letter k is used instead of the prefix kilo-. 1 kilovolt is, therefore, 1 kV.
  • mega- is the prefix we use to denote 1 million of a quantity. A megahertz, for example, is 1 million Hertz. The unit of frequency is the Hertz. (T5C05) It is equal to one cycle per second. Often, the letter M is used instead of the prefix mega-. 1 megahertz is, therefore, 1 MHz.

Here are some examples:

  • 1,500 milliamperes is 1.5 amperes. (T5B01)
  • Another way to specify a radio signal frequency of 1,500,000 hertz is 1500 kHz.
    (T5B02)
  • One thousand volts are equal to one kilovolt. (T5B03)
  • One one-millionth of a volt is equal to one microvolt. (T5B04)
  • If an ammeter calibrated in amperes is used to measure a 3000-milliampere current,
    the reading it would show would be 3 amperes. (T5B06)
  • If a frequency readout calibrated in megahertz shows a reading of 3.525 MHz, it would
    show 3525 kHz if it were calibrated in kilohertz. (T5B07)
  • 1 microfarad is 1,000,000 picofarads. (T5B08) (Farad is the unit for capacitance.)
  • 28.400 MHz is equal to 28,400 kHz. (T5B12)
  • If a frequency readout shows a reading of 2425 MHz, the frequency in GHz is 2.425 GHz. (T5B13)

When dealing with ratios—especially power ratios—we often use decibels (dB). The reason for this is that the decibel scale is a logarithmic scale, meaning that we can talk about large ratios with relatively small numbers. At this point, you don’t need to know the formula used to calculate the ratio in dB, but keep in mind the following values:

  • 3 dB is the approximate amount of change, measured in decibels (dB), of a power increase from 5 watts to 10 watts. (T5B09) This is a ratio of 2 to 1.
  • -6 dB is the approximate amount of change, measured in decibels (dB), of a power decrease from 12 watts to 3 watts. (T5B10) This is a ratio of 4 to 1.
  • 10 dB is the approximate amount of change (actually it is the EXACT amount of change), measured in decibels (dB), of a power increase from 20 watts to 200 watts. (T5B11) This is a ratio of 10 to 1.

Should amateur radio operators know how to use the Internet?

My No-Nonsense Technician Class License Study Guide is available for free here on KB6NU.Com

My No-Nonsense Technician Class License Study Guide is available for free here on KB6NU.Com

Often, I get requests from hams teaching courses to print a number of copies of my No-Nonsense Technician Class Amateur Radio License Study  Guide. I normally reply that individuals are free to download and print the study guide if they like, but that I don’t usually give permission to print out many copies. There are a couple of reasons for this, the main one being that when individuals each download their own copies, I get a better indication of how many are actually using it.

Sometimes, they’ll come back and say that the reason they’re asking for permission to print copies is that some of the students aren’t very Internet-savvy, and that they may not know how to get on my website and download the study guide. That, of course, begs the question, “Should amateur radio operators know how to use the Internet?”

The NCVEC question pool committee obviously thinks so. There are a number of questions on the test about IRLP and EchoLink, both of which use the Voice Over Internet Protocol (VOIP) to allow communications over the Internet.

Don’t get me wrong. I love it that folks want to use my study guide, and I will continue to make it free for as long as I continue to produce it. It seems to me, however, that knowing how to use the Internet is now a basic skill that every ham should have. That being the case, I’m going to continue to ask that teachers that want to use my study have their students download it from my website and not print copies for them.

Transforming impedances: Question G5C07

In the last two weeks, I’ve received e-mails from two readers of The No-Nonsense General-Class License Study Guide. Both questioned my explanation of how transformers transform impedance. I wrote:

Transformers are also used to transform impedances. The impedance ratio is also related to the turns ratio, but the transformation is equal to the square of the turns ratio. The turns ratio of a transformer used to match an audio amplifier having a 600-ohm output impedance to a speaker having a 4-ohm impedance is 12.2 to 1. (G5C07)

Doug wrote, “The only way I can reproduce the calculation is by taking the square root of the turns ratio.” His comment made me see where my explanation could be a bit misleading. I wrote back:

Think about it this way. An impedance transformation can go either way. When transforming from a higher impedance to a lower impedance, you divide by the square root of the turns ratio. When transforming a lower impedance to a higher impedance, you multiply by the square of the turns ratio. In either case, the impedance ratio is “related” to the square of the turns ratio.

I love getting feedback from my readers. Feedback like this helps me improve my study guides. If you have used one of my study guides, and have a comment or question about any of the material, please feel free to contact me.

ARRL instructor’s newsletter sports new name, look

Radio Waves

It’s been a long time coming—more than two and a half years, in fact—but the ARRL has finally published another issue of the newsletter for  instructors and teachers. It’s now called Radio Waves, and the October 2013 issue contains articles on:

  • teaching amateur radio in elementary school,
  • the new band chart of Tech-only privileges,
  • an exam-prep game modeled on the game show Jeopardy,
  • the upcoming 2014 update to the Technician Class question pool, and
  • 2013 licensing statistics.

Unfortunately, the majority of the issue is devoted to the ARRL’s Education and Technology Program, which sponsors programs for classroom teachers. I may be missing something here, but while I think that these are useful programs, they have little value for instructors teaching amateur radio classes.

At any rate, let’s hope that it doesn’t take the ARRL another two and a half years before they publish another issue of this newsletter.

Thanks to all my customers

extra-class-cover-375x500When I sign into the admin section of my website, I get a summary of how well sales of my No-Nonsense Extra Class License Study Guide are going.  Here are the numbers from the last quarter.

  • July 2013 – 32
  • August 2013 – 39
  • September 2013 – 37

Over the past year, by quarter, I’ve sold the following number of copies:

  • Jul 2013 – Oct 2013 – 112
  • Mar 2013 – Jul 2013 – 115
  • Dec 2012 – Mar 2013 – 133
  • Oct 2012 – Dec 2012 – 73

These are just the sales made from my site, and don’t include the sales on Amazon or Barnes&Noble.

I would just like to thank you all for buying my books. It’s been very gratifying to me to be able to help so many hams get and upgrade their licenses. Please pass the word about my study guides if you found them at all useful.

Looking to the future, the Technician Class question pool will be updated in 2014. You can be sure that I will be updating my study guide well in advance the July 1 switchover date. My goal is to have it available by mid-May 2014 and bring some copies with me to Dayton.

A new way to teach Ohm’s Law?

I’ve been trying to come up with some short videos that I could post on YouTube that would go over the same material that I do in my one-day Tech classes. In my classes, I basically teach the answers to the questions, but I also try to give a little bit of context, so that they get some idea anyway of the bigger picture.

I start out with the day with electrical principles. That means talking about questions in section T5. Obviously, Ohm’s Law is a big part of section T5. So, I searched YouTube to see what other videos are already out there that explain Ohm’s Law.

In doing this, I ran across a video by a guy named Daniel Sullivan. Apparently, he teaches classes for electricians and industrial technicians. Here’s his video, “Teaching Ohm’s Law to Techs – Part 1″:

One of his main points is that we shouldn’t use the notation E, I, and R when talking about Ohm’s Law. Instead, he says, we should use the notation V, A, and ?. These are, after all, the symbols that we use to denote the units of voltage, resistance, and current, and the symbols that  you see on a meter. If you buy that logic, then the answer to question T5D01 which reads:

What formula is used to calculate current in a circuit?

should be:

Current (A) equals voltage (V) divided by resistance (?).

The more I think about this, the more I like it, and I’ve just e-mailed the Question Pool Committee to see what they think about this. I’d like to know what you think, too.

Activity Report: Dayton, General class, Mini Maker Faire, Monroe hamfest

I realized the other day that I haven’t really been reporting on my own amateur radio activities lately. At first, I thought it was because I hadn’t really done much lately, but that’s not really true. So, here’s a report of some recent activity.

U-M ARC celebrates 100 years. The University of Michigan Amateur Radio Club recently celebrated it’s 100th anniversary. I helped them celebrate by operating during their special event on April 14th, 2013. The event was held on the  Central Campus Diag, and recognized the University’s first licensing as station 8XA in June of 1913. It was really cold and rainy that day, and the bands were pretty bad, but they had some hot coffee and donuts, and we had fun anyway.

Dayton 2013

In some ways, Dayton was kind of a washout for me. I came down with some  kind of stomach flu a couple of days before Dayton, and was even considering not going at all, but since I enjoy FDIM, and I was scheduled to speak at the  instructor’s forum on Friday morning, I decided to go.

As usual, FDIM was a blast. There were lots of good ideas being thrown around. I especially enjoyed the talk on receiver design by Rick, KK7B, and the talk on baluns by Rick, W7EL. They were all very good, though. The QRP-ARCI does a very good job lining up speakers.

I even participated in Vendor Night. Between talks, they had asked for volunteers to help set up tables for the vendors. It occurred to me that, if it didn’t cost much, I could show the CD-ROMs that I’d brought with me and pass the word about my free downloads. Well, it turned out that it didn’t cost a thing, so I asked for and they gave me a table.

I didn’t really expect to sell anything, as most of the folks there I’m sure had Extra Class licenses, but I did manage to sell one, and to talk to a lot of people about the study guides. So, overall, it worked out great.

On Friday, the entire morning was taken up, getting my speaker badge and then participating in the instructor’s forum. My talk about conducting one-day Tech classes went pretty well, but the forum didn’t end until noon, leaving me only five hours to peruse the flea market. That’s a fair amount of time, but I still wasn’t 100%, and my heart wasn’t really in it. I ended up buying not a single thing.

Saturday morning, I decided not to go to the Hamvention and just to pack it up and head home. I guess thinking about it, it wasn’t a complete washout, but I certainly didn’t get as much out of Dayton as I have in years past.

General class
I started a teaching a General Class course on Thursday evenings at the Hands-On Museum a couple of weeks ago. It’s a small class, but they’re enthusiastic. I am, of course, using my study guide as the text. Doing this has shown me how I can improve the next edition. I’ll be beefing up the explanations in a few spots and moving some things around.

Mini Maker Faire 2013 a success. This year’s Ann Arbor Mini Maker Faire was held about a month ago, and if you ask me, it was a great success. As we have done for the past several years, Dave N8SBE and I anchored the station, and Prem KD8SVR, one of my recent Tech students joined us.

The table they first assigned us was inside, with no clear path for our coax to get outside to the antennas. After some negotiation, we found ourselves relocated outside. Then, once Dave had gotten his K3 gear all set up, they decided to move us again! We finally got settled about 10:45 am.

We got the usual type of visitors:

  • Those who were already hams. They stopped by to ragchew a little.
  • Inactive hams. We tried to get them energized to get back on the air. One of these was KA8ODD. What a great call!
  • Interested people. I passed out my card liberally, pointing them to my free study guide.
  • Not-so-interested people. I at least tried to get them and/or their kids to send their name in Morse Code.

One thing that I found interesting is how some people seem to naturally take to Morse Code while others do not. For those who have a natural fist, I can easily make out their names when they send it by looking up the characters on the code chart. When I do copy a name, I reach out my hand and say, “Hi, John (or Mary or whomever). Nice to meet you.” They seem to be amused that I was able to figure out their name from their sending.

Unfortunately, not everyone is a natural. If I can’t make out the name, I smile and say, “Good job!”

Monroe hamfest
Yesterday morning, I drove town to Monroe for a hamfest. It’s a small hamfest, but fun. Every time I’ve gone, the weather’s cooperated, and this is important because most of the sellers are outside. Yesterday, the temperature was in the upper 60s, and the sky started out overcast, but as the morning progressed, the sky cleared, and it was just beautiful.

I almost bought a Jones paddle for $75, but since I really don’t need another paddle, I put off the purchase until I was about ready to leave. By the time I got back to that seller, he’d already sold it to someone else. I’m more than OK with this. I saved 75 bucks! I did end up buying some PL-259s and some 3.5mm stereo plugs. As Ralph would say, this was the “requisite handful of connectors.”

From my Twitter feed: no code test, Contest U, iPhone sig gen

Jeff K1NSSJeff K1NSS @K1NSS
NO CODE TEST! If that don’t grab ‘em, I argue MIGHT AS WELL! Outreach according to http://www.dashtoons.com  #hamr #qrp pic.twitter.com/vAngtDNmmu

Matt MaszczakMatt Maszczak @rocknrollriter
For the new or newer op looking into contesting: http://www.arrl.org/news/view/dayton-contest-university-videos-available-on-youtube?utm_source=twitterfeed&utm_medium=facebook …

Jacob BeningoJacob Beningo @Jacob_Beningo
Turn a Smart Phone into a Signal Generator | EDN http://www.edn.com/electrical-engineer-community/industry-blog/4416138/1/Turn-a-Smart-Phone-into-a-Signal-Generator … via @edncom

I love to hear from readers

Today’s e-mail brought good news from two readers.

Chris, AG6TJ, wrote, “Hi, Dan. Sorry I forgot to let you know, I passed my Extra on the first try! I read it [the No-Nonsense Extra Class License Study Guide] twice, and in between took online practice tests. It was a 50/50 chance I was going to pass, but did only missing six! The nice thing I like about your study material is that it just isn’t memorizing the answers—I actually learned  from it as well.

Diann, KK6BSQ, said, “Became an Extra Class this am about 11:00. Thanks to your great study guide!”

I love to hear that from my readers.