ARRL BoD tackle legislative issues, pension plan, centennial

ARRLThe ARRL sent out the minutes from the July 31 Board of Directors meeting this morning. As usual, legislative issues played a big part. The ARRL lobbyist, John Chwat reported that he believed that HR 607 is no longer a threat. HR 607 was a bill put forward by Rep. Peter King (R-NY), Chairman of the House Homeland Security Committee, that would have re-assigned a portion of the 440 MHz band. The minutes note that, “The FCC study of impediments to Amateur Radio emergency communications was included in the Middle Class Tax Relief and Job Creation Act of 2012 thanks to the support of House Energy and Commerce Committee Chairman Upton and Communications and Technology Subcommittee Chairman Walden, among others.”

There was also a note about extending PRB-1 to private land use regulations. It says, “The study being prepared for Congress by the FCC is expected to conclude that the Commission will extend the limited preemption provisions of PRB-1 to private land use regulations only if directed by Congress to do so.” So, don’t look for that any time soon.

There were also several discussions of the pension plan for ARRL employees. They’re terminating the defined pension plan. No mention of what effect this will have on the employees or the financial health of the ARRL.

Finally, there was discussion of the ARRL centennial. The ARRL turns 100 in 2014. That’s not all that exciting to me. How about you?

Read the entire minutes.

Mobile Apps for Ham Radio?

So, I’m at a mini-conference for mobile app developers. I currently don’t do mobile apps, but since I am a freelance Web developer, and a lot of the stuff people used to do on the Web is moving to mobile devices, I figured I better get on board.

For example, I do a website for a construction-industry trade magazine. This website is reallycrying to have a companion mobile app. One reason for this is that many of the readers are mobile types. That is to say that they are on the road a lot and not sitting in front of a computer.

The question is how the mobile app would be different from the website. Will the mobile app users want to read magazine articles? Will they want more news? Is there anything that we can give them to help them do their jobs better?

Of course, after pondering this for a while, I started thinking about ham radio mobile apps. There are already EchoLink apps out there, and I would suppose that there are already study guide/practice test apps (although possibly not). One idea that occurred to me is to develop an app that would allow users to send Morse Code to one another. This could be used for code practice as well text (code?) messaging.

What do you think? Are there any good amater-radio mobile apps out there already? What kind of amateur-radio mobile apps would you like to see?

Olympic special event station on the air

2012L - the London Olympics special event station

The London Olympics special event station, 2012L, is on the air. Says the website,

The call sign of the London Flagship Amateur Radio Station celebrating the London 2012 Olympic Games and Paralympic Games. This unique amateur radio special event radio station is based at the Royal Greenwich District Scouts Activity Centre in New Eltham, south-east London. Eltham is in the Royal Borough of Greenwich, one of the six “host boroughs” for the Games.

We plan to make at least 60,000 contacts during the seven weeks of round the clock operation. The first contact was made on the afternoon of Wednesday 25th July, when the first Games football event took place in Cardiff. Operation will continue until the end of the Paralympics on Sunday 9th September.

They have been apparently generating huge pileups, especially on 20m. I’m hoping to work them before they close down.

UPDATE
GW0RYT informs me via Twitter that there is also an Olympic special event station, 2012W, in Wales.

Extra Class question of the day: AC waveforms: sine, square, sawtooth and irregular waveforms; AC measurements; average and PEP of RF signals; pulse and digital signal waveforms

We use all different kinds of waveforms in amateur radio. It is, therefore, important to know about the different types of waveforms and how to measure their parameters. One of the most important parameters of a waveform is its period. The period of a wave is the time required to complete one cycle. (E8A08) The frequency is the inverse of the period. For example, if the period of a wave is 1 msec, or .001 s, the frequency of that wave is 1 / .001s, or 1000 Hz.

Another parameter that we need to know about a waveform is it root mean square, or RMS, value. The root-mean-square value of an AC voltage is the DC voltage causing the same amount of heating in a resistor as the corresponding RMS AC voltage. (E8A04) Because of this, the most accurate way of measuring the RMS voltage of a complex waveform would be measuring the heating effect in a known resistor. (E8A05)

If the waveform is regular, it’s relatively easy to calculate the RMS value. In the case of a sine wave, the RMS value is 0.707 times the peak value. You use the RMS voltage value to calculate the power of a wave.

The type of waveform produced by human speech is, however, irregular. (E8A09), and  the characteristics of the modulating signal determine the PEP-to-average power ratio of a single-sideband phone signal. (E8A07) This makes calculating or measuring the average power more difficult.

If you know the peak envelope power (PEP), though, you can make a pretty good guess at the average power. The approximate ratio of PEP-to-average power in a typical single-sideband phone signal is 2.5 to 1. (E8A06) Put another way, the average power of an SSB signal is about 40% of the peak power.

It used to be that all the waveforms we used in amateur radio were analog waveforms, but digital waveforms may be even more important than analog waveforms. An advantage of using digital signals instead of analog signals to convey the same information is that digital signals can be regenerated multiple times without error. (E8A13) All of these choices are correct when talking about the types of information that can be conveyed using digital waveforms (E8A12):

  • Human speech
  • Video signals
  • Data

Perhaps the most common digital wave form is the square wave.  An ideal square wave alternates regularly and instantaneously between two different values. An interesting fact is that a square wave is the type of wave that is made up of a sine wave plus all of its odd harmonics is. (E8A01)

Another type of wave used in amateur radio is the sawtooth wave. A sawtooth wave is the type of wave that has a rise time significantly faster than its fall time (or vice versa). (E8A02) The type of wave made up of sine waves of a given fundamental frequency plus all its harmonics is a sawtooth wave. (E8A03)

Digital data transmission is one use for a pulse modulated signal. (E8A11) Narrow bursts of energy separated by periods of no signal is a distinguishing characteristic of a pulse waveform. (E8A10) The waveform of a stream of digital data bits would look like a series of pulses with varying patterns on a conventional oscilloscope. (E8A15)

To make use of digital techniques in amateur radio, such as digital signal processing or DSP, we must convert analog signals to digital signals and vice-versa. Sequential sampling is one of the methods commonly used to convert analog signals to digital signals. (E8A14) When converting an analog signal to digital values, an analog to digital converter measures, or samples, the value of the analog signal at different points, and converts that measurement to a numeric value. Those numbers are then input to a processor or directly into memory.

From the trade magazines – 7/25/12

Here are a couple of items from the electronics engineering trad magazines that hams might find interesting:

Digital and analog PC TV dongles—the basics. Some amateur radio operators are using these dongles as a software-defined radio (SDR).

Can public-safety radio’s P25 survive LTE? P25 has been with us since 1988, but its capacity and bandwidth are being obsoleted by the latest and anticipated next generations of cellular technology.

Material effectively replaces gold. Impact Coatings claims that its Silver MaxPhase performs like gold while carrying a much lower price tag.

Frequency allocation chart cuts to the chase

On the HamRadioHelpGroup there was recently talk about frequency allocation charts. Someone pointed to the NTIA chart. This is a great chart, but several hams seemed to prefer the xkcd chart:

xkcd frequency allocation chart

Click on the image to see the full-sized chart.

First Annual Antenna Party on the Air

Tripp Brown, AC8S, e-mail me yesterday:

I’m sponsoring the first anual Antenna Party on the Air the third weekend in in September! We’ll have hundreds, if not thousands, of stations on the air that weekend! So many antennas will be used by so many stations!

Whether you want to make just a few contacts, or, if you want to make a lot of contacts, don’t sit this one out! Get on the air and have fun talking about your antenna and learning about other’s antennas.

Here are more details:

Starts: 2300Z, September 21

Ends: 0400Z, September 23

Bands: 160, 80, 40, 20, 15, 10, 6, and 2 meters

Modes: AM, CW, FM, SSB

Purpose:
To get as many hams on the air as possible that weekend and to help hams learn about different types of antennas. The idea is for the participants to demonstrate their antennas and describe them to other hams, so that if they hear one they like, they will be able to put up one just like it.

Exchange:
Signal report, US state, Canadian province, or dx country, antenna being used, where it’s located, for example, on a balcony, in an attic, how high up it is, and, how much power you’re running. An example exchange might be:

you’re 59 Alaska, running a long wire, in a backyard, up 10 feet, running 200 watts.

Other Rules:

  • Stations should only be worked once per band, once per mode.
  • Only single station, single ops. This will get as many stations on as possible.
  • Power:  200 watts or less.
  • Must run only from a fixed location, such as, your place of residence.
  • Logging: no logs need to be submitted. Just take down any info about the other stations antenna that you need to know, such as what is given by the station. The station can give as much info on the antenna as needed, such as, how to build it, or, tell the station you’re working, that they can find directions on how to build and put up the antenna at a certain web site, or, to send you an email with a request on info about the antenna.

TAPR accepting Hermes orders

From the tapr-announce mailing list:

TAPR is pleased to announce that Hermes, an HF transceiver incorporating the capabilities of the existing “Atlas Bus” HPSDR receiver, exciter, and computer interface onto a single board, is now available for order at http://tapr.org/kits_hermes.html

The Hermes board is completely assembled and tested, and is offered at the following prices.

TAPR member: $895
TAPR non-member: $940

The order page will close Wednesday July 25th, so don’t delay!

Please note that TAPR will be building only one production run of Hermes boards, and will only build the number necessary to fulfill the orders received on or before before the July 25th cutoff date.

Estimated delivery is October 15, and earlier if possible. Be a part of history and support HPSDR!

More information here: http://openhpsdr.org/wiki/index.php?title=HERMES

Order here: http://tapr.org/kits_hermes.html

Software-defined radio is one of those things that I just really haven’t gotten into yet, and I feel like I’m getting further and further behind. How about you? Should I really care?

Kudos to the ARRL

ARRL Happy Birthday

As you know if you’ve read this blog for very long, I’m not overly generous when it comes to praising the ARRL. I do have to give them some kudos for this latest promotion, however. A couple of weeks ago, I got the above postcard in the mail offering me a $10 discount on any purchase from the ARRL website. Today, being my birthday, I got a followup e-mail, reminding to take advantage of this offer.

I like this effort a lot. It does show some member appreciation, and it will make some purchase more affordable. Kudos to the ARRL!

Operating Notes – 7/16/12

OHR Sag 2012

KB6NU providing communications for the 2012 One Helluva Ride (OHR). Photo: Dikhran Khanian, KC8UXT

Saturday, I made absolutely no CW contacts on the HF bands. I spent all day riding around in a sag wagon supporting a local bicycle event called One Helluva Ride. That’s yours truly in the front seat of the SAG wagon in the photo at right. It was very hot and sunny, and we spent a lot of time picking up people who just couldn’t make it.

You can’t really see it in the picture, but we got a cool T-shirt with a picture of a Sandhill Crane on it. Sandhill Cranes are one of the largest birds in North America, and there’s a crane reserve in the are where they were bicycling. They are truly spectacular birds, and you can often spot them while driving or bicycling in that area. I  saw a pair out in a farm field on Saturday.

Although the sag wagons were pretty busy picking up passengers, we were fortunate in that there were no major accidents or injuries. We had a good crew, too, including several that I taught, either in one of my one-day classes or in one of the General classes. One of them, Mike, KD8SRU, was in the most recent class.

Sunday, I went down to the museum for a little while. It was only a little while because the band conditions were so poor. One of my Twitter friends blamed this on a coronal mass ejection. I heard nearly no signals at all on 20m, either CW or phone. I did manage to eke out one CW contact, but then just gave up because it was so hard to make contacts.

Later that evening, conditions were a little bit better. I did manage to make one contact with a station in Florida on 30m, but the propagation was really strange. The only station spotting my CQs on reversebeacon.net was PJ2T.  I QSYed to 40m and made one contact there before pulling the plug.