After reading that, I’m thinking, are the hams a lot younger in Saipan that they are  in better shape than us hams on the mainland? And, even if they are, how do they get so many to turn out that they can form a league?

I e-mailed the author, and here’s what she said:

Thanks for your email. The members/officials of the radio club organized the league and there are some (not all) members who also played. The rest of the players are youth and B league ranked players.

Mystery solved. While I was on the site, I surfed around a bit and discovered that they play a lot of basketball on Saipan. At least the paper had quite a few stories about games played in a variety of leagues.

Fierce Homeland Security

In a paper (.pdf) dated Jan. 24, the National Institute for Standards and Technology (NIST) Visiting Committee on Advanced Technology says unlicensed spectrum in the 2.4 gigahertz to 5 GHz spectrum, television white space and possibly even 60-100 GHz spectrum could augment the planned national broadband network….In addition, the network should incorporate Internet protocol packet switching technology to permit ad hoc network formation, the paper says. “Use of the Internet Protocols does NOT necessarily imply use of the public Internet,” it emphasizes.

This is just what amateur radio operators do when we set up nets in response to an emergency, although are networks are usually voice-only.  Why aren’t we doing any digital networking? Well, for one thing, there’s currently no commercial equipment available for purchase, and many of those involved in ham radio emergency communications are just not interested in investing the time and money required to get a digital network like this up and running.

I’ll say again what I’ve said before. We need a group like AMSAT that’s devoted to advancing the state-of-the-art in emergency communications. Unless someone really takes the bull by the horns, amateur radio is going to fall farther and farther behind in this area.

The reason for this is that the USB signal extends from the carrier frequency, which is the frequency that the transceiver is displaying, up 3 kHz. When you set the transceiver to 14.349 kHz, the upper sideband will extend up to 14.352 MHz, and because the amateur radio band stops at 14.350 MHz, some of the transmission will fall outside the band.

A similar thing happens, but in reverse, when you operate lower sideband, or LSB. When using a transceiver that displays the carrier frequency of phone signals,the lowest frequency at which a properly adjusted LSB emission will be totally within the band is 3 kHz above the lower band edge. (E1A02) With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency? No, my sidebands will extend beyond the edge of the phone band segment. (E1A04)

The lower sideband will extend down 3 kHz from the carrier frequency. So, when your transceiver is set to 3.601 Mhz, your signal will extend down to 3.598 MHz, which is outside the phone band.

Tworse Key:  a tweeting Morse key. An open design exercise in interface archaeology, that decodes the input from a classic Morse key to send twitter messages. The source code and hardware schematics are available online http://modin.yuri.at/tworsekey/

Design analog chips. According to the website, this freely downloadable book is “a comprehensive introduction to CMOS and bipolar analog IC design. The book presumes no prior knowledge of linear design, making it comprehensible to engineers with a non-analog background. The emphasis is on practical design, covering the entire field with hundreds of examples to explain the choices. Concepts are presented following the history of their discovery.”

DashToons.Com. Jeff, K1Nss presents the illustrated adventures of Dash!, the dog-faced ham.

Ham radio usage needs fixed

Dear Editor:

Attention amateur radio operators, it is easy to forget where amateur radio is and what we are here for.

First let me give you a story. A man sat in his car out of gas during freezing weather, on January the 29th of this year. He was a Ham operator and he had called several times for assistance. No answer came.

For those of you who know a little about sub-freezing weather, you can go into hypothermia in less than an hour inside a car and it takes 20 minutes outside.

This man never got any help from the radio but his son, knowing he was stranded, walked 5 miles to where he was with a small can of gas that held about a gallon-and- a-half. They made it home safely, no thanks to Amateur radio assistance.

You wonder why I didn’t help that man inside that car … well that man was me. You see, at home I monitor the local repeater, but now I have lost my faith in Ham radio.

People you need to listen up, if were not going to monitor local repeaters of call channels on a 24-hour basis, than Ham radio is not worth saving. Is this the message you want to send to those who are after our frequency?

Amateur radio is for the recognition of emergency communication first, and a privilege to use it as a hobby second -not anything other than that.

Start monitoring those frequencies, and set up a schedule for volunteers on a 24-hour basis. If we are to live up to our name, then we need to listen to those calls of emergency, with your local clubs.

This could have been a bad car accident happening in the early-morning night, with severe bleeding, or worse.

We must not fail those who need us in these times.

I do want to thank the officer who gave my son a ride back with gas, and we did get home safely.

Walter Kernaich
East Liverpool

So, is someone monitoring your repeater?

Ham radio: Last means of communications in a disaster. This short spot appeared on KVAL-TV in Eugene, OR. The two-minute video describes how ham radio operators helped out  during the recent flooding in the Eugene area.

Scout training (and ham radio) saves the day for backcountry skiers. Ham radio plays a part in the rescue of two Colorado skiers.

GET INVOLVED: Club helps keep area safe. The San Angelo Amateur Radio Club works with the county and city Offices of Emergency Management, the police and sheriff, and all the fire departments in the Concho Valley. They are willing to work with anyone if it will help make Tom Green County a safer and better place to live or a more effective community.

• Antennas don’t really have gain in the same way that an amplifier has gain. When you use a linear amplifier, you get more power out than you put in. Since transmitting antennas are passive devices, there’s no way to get more power out than you put in.
• It’s not easy to measure antenna gain. There is no antenna gain meter that you can simply hook up to an antenna to measure its gain.

So, what is antenna gain? According to question E9A08, antenna gain is the ratio relating the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna. What this means is that when you talk about antenna gain, you have to know what kind of antenna you’re comparing it to.

When talking about antenna gain, antenna engineers often refer to the “isotropic antenna.” An  isotropic antenna is a theoretical antenna used as a reference for antenna gain. (E9A01) An isotropic antenna is an antenna that has no gain in any direction. (E9A03) That is to say it radiates the power input to it equally well in all directions.

Let’s take a look at a practical example. I often say that the 1/2-wavelength dipole antenna is the most basic amateur radio antenna. Well, the dipole actually has some gain over isotropic antenna. The reason for this is that it is directional. The signal strength transmitted broadside to the antenna will be greater than the signal strength transmitted off the ends of the antenna.

The gain of a 1/2-wavelength dipole in free space have compared to an isotropic antenna is 2.15 dB. (E9A02) Sometimes, you’ll see this value as 2.15 dBi, where dBi denotes that  and isotropic antenna is being used for this comparison.

Since the isotropic antenna is a theoretical antenna, some think it’s better to compare an antenna to a dipole antenna. An antenna will have a gain 3.85 dB compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna. (E9A13) You obtain this value by simply subtracting 2.15 dB from the 6 dB figure:

Gain over  a dipole = gain over an isotropic antenna – 2.15 dB =
6 dBi – 2.15 dBi = 3.85 dBd

Sometimes, the gain over a dipole is denoted as dBd.

Similarly, an antenna has a gain of 9.85 dB compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna. (E9A14):

Gain over  a dipole = gain over an isotropic antenna – 2.15 dB =
12 dBi – 2.15 dBi  = 9.85 dBd

Having said that, you should submit a log, even if you only make a handful of contacts. At WA2HOM, we participated in the CQWW SSB contest last fall. We only operated for a short time, as we can only operate when the museum is open. Even so, we recently received a certificate for being the highest scorer in the single transmitter, multi-operator category in the 8th call district. As it turns out, we were the only entry in this category, but so what? We’re champions!

Now, let’s look at the wrong answers:

• Interference to other amateurs is unavoidable and therefore acceptable. It’s bad practice–as well as illegal–to cause harmful interference whenever you’re operating, even during contests.
• It is mandatory to transmit the call sign of the station being worked as part of every transmission to that station. Part 97 requires only that you identify your station, at least once every ten minutes during a contact and at the end of a contact. Even during normal operation, you don’t have to give the callsign of the station being worked.
• Every contest requires a signal report in the exchange. Many contests no longer require a signal report in the exchange.The reason for this is that the signal reports exchanged are rarely true signal reports. That being the case, why bother to exchange them?

In conjunction with that, I’m also planning to do an “Extra Class Question of the Day” here on my blog. In reality, the “question of the day” will cover more than one question, as so many of them are related. As in my study guides, the correct answer will be highlighted, and the question will be marked with the pool question number.

Today’s question of the day is about resonance. Resonance is one of the coolest things in electronics. Resonant circuits are actually what makes radio, as we know it, possible.

What is resonance? Well, a circuit is said to be resonant when the inductive reactance and capacitive reactance are equal to one another. That is to say, when

2πfL = 1/2πfC

where L is the inductance in henries and C is the capacitance in farads.

For a given L and a given C, this happens at only one frequency:

f = 1/2π√(LC)

This frequency is called the resonant frequency. Resonance in an electrical circuit is the frequency at which the capacitive reactance equals the inductive reactance.(E5A02)

Let’s calculate a few resonant frequencies, using questions from the Extra question pool as examples:

The resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads is 3.56 MHz. (E5A14)

f = 1/2π√(LC) = 1/6.28x√(50×10^-6 x 40×10^-12) = 1/2.8×10^-7 = 3.56 MHz

Notice that it really doesn’t matter what the value of the resistance is. The resonant frequency would be the same is R = 220 ? or 2.2 M?.

The resonant frequency of a series RLC circuit if R is 56 ohms, L is 40 microhenrys and C is 200 picofarads is 1.78 MHz. (E5A15)

f = 1/2π√(LC) = 1/6.28x√(40×10^-6 x 200×10^-12) = 1/5.6×10^-7 = 1.78 MHz

The resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads is 7.12 MHz. (E5A16)

f = 1/2π√(LC) = 1/6.28x√(50×10^-6 x 10×10^-12) = 1/1.4×10^-7 = 7.12 MHz

The resonant frequency of a parallel RLC circuit if R is 47 ohms, L is 25 microhenrys and C is 10 picofarads is 10.1 MHz. (E5A17)

f = 1/2π√(LC) = 1/6.28x√(25×10^-6 x 10×10^-12) = 1/9.9×10^-7 = 10.1 MHz

Those who say it’s not point out that years ago we had magazines, such as Popular Electronics and Electronics Illustrated, companies like Heathkit. They also point out that it was possible to disassemble TVs and radios for the parts and use them for your own projects.

Schweber, however, thinks that it is easier today for hackers and experimenters. He writes that  those magazines may be out of business, but we now have access to “countless user groups, informal forums, and blogs” on the Internet.

One thing he failed to mention was the hacker/maker groups that have sprouted up around the country. Here in Ann Arbor, for example, we have a group called Go Tech that provides support for hackers and makers of all stripes. You’ll find groups like this all around the U.S.

I tend to agree with Schweber that while the environment has certainly changed for experimenters, it is definitely better. What do you think?