From my inbox: radio demos, free EM simulation, radio builder’s BBS

Here are some items of note from my inbox:

  • My partner in crime down at WA2HOM, Ovide, K8EV, is working with Professor Ray, who does science shows for kids down at the Ann Arbor Hands-On Museum, to develop a show about radio. In researching this, Ovide happened across the Happy Scientist’s experiment on AM and FM radio waves. There are a bunch of other interesting experiments on the site, but you have to subscribe to the site, in other words pay, to view them.
  • openEMS is a free and open electromagnetic field solver using the FDTD method. Matlab or Octave are used as an easy and flexible scripting interface. I haven’t yet tried this out, but it sounds like a neat tool to play around with.
  • TheRadioBoard is a forum for the homemade radio builder. There are forums for crystal radio builders, tube radio builders, and solid state radio builders, as well as a swap forum and antenna forum.

Solar activity: What do the numbers mean?

On the HamRadioHelpGroup mailing list, there’s been a discussion of solar activity and how it affects radio propagation. Several websites were mentioned, and I thought I’d record them here. I really have no personal experience with these sites, except maybe to take a quick look at them if the bands seem particularly dead.

  • SunspotWatch.Com. This site is run by Tomas Hood, NW7US. He is the propagation editor for CQ magazine. Geoff, N7PGN says, “[Hood] as some very good information on his website and his propagation and space weather website,
  • HF Propagation Tools and Solar Data.

    Tiny, AB3RW, says, “I use this website. Thre is a tab at the top labeled using data that will help you out a lot.”

  • W4HM’s Daily MF/HF/6M Frequency Radio Wave Propagation Forecast. This site is run by W4HM, who worked in space and terrestrial level weather forecasting for some private weather forecasting companies and federal government agencies for 31 years before retiring from the business in 2004.

From the trade magazines – September 14, 2012

Nikola Tesla slideshow: Images and articles from Tesla’s writings. This slideshow contains a sampling of images and excerpts from John Ratzlaff’s collection, which are all obtainable on the Internet. There are also several links to other awesome sites with info on Tesla.

Giga Sample and Direct-RF Sampling ADCs Overview. This video from TI demonstrates TI’s direct RF-sampling ADC IMD3 performance at 700 MHz and 2.7 GHz, allowing the elimination of one or more down-conversion stages. Features: sample rates up to 3.6 GSPS, dynamic performance up to 2.7 GHz inputs, largest high-res Nyquist zone at 1.8 GHz, and pin compatibility with TI’s 10- & 12-bit ADC families.

The basics of FPGA mathematics. For better performance, you can implement some digital signal processing (DSP) algorithms in an FPGA. This article takes a look at the rules and techniques that you can use to develop mathematical functions within an FPGA or other programmable device.

Things I learned about ham radio while twittering

As if I didn’t have enough to do already, I’ve started using Twitter again. Now, I’ve always been on Twitter. As you can see from the cute, little birdie icon in the left-hand column of this page, you can follow me there, but it’s been a passive participation. I have this blog set up to send a “tweet” whenever I create a new post.

Now, however, I’m more actively tweeting. Last night, for example, I tweeted, “Calling CQ on 10.115 MHz.” The tweet didn’t result in any QSOs, but one guy did reply, “I think that only works if you’re using a radio :)”

Although my Twittering last night didn’t result in any new QSOs, I did find a few items of interest:

I don’t know for how long I’ll be active on Twitter, but chances are for quite a while this time.

Random Links

Here are some more links to websites that ham radio ops will find amusing and/or useful:

  • Climbing a really tall tower. Ever wonder what it’s like to climb a tower nearly 1,800 feet tall? Watch this video.
  • Software for people who build things. Although some of the software on this site is fairly old, it also has an amazingly huge collection of hints and kinks on a wide variety of topics. For example, there is a great tip on how to estimate a tap or drill size.
  • Social networking for hams. Although most hams seem to be anti-social, not all of us are. This is a website for those that aren’t.
  • QRQ CW Info, Ops, and Tips. More social networking, but for hams that like to work CW at high speeds. Most of these guys go a lot faster than I can, but I’m hoping to learn something from them.

Random Links

Here are a bunch of random links to interesting and useful websites:

  • 1×1 Callsign Search. It’s often difficult to know who’s using a 1×1 special-event callsign. Looking them up on QRZ.Com doesn’t work because they’re only issued for short-term use, and they are re-used over and over. To help you identify that 1×1 callsign, the W5YI VEC has set up this searchable database. Type in a call, and it tells you who’s used the call recently and who will be using it in the near future. Very cool.
  • Arcane Radio Trivia. True to its name, this blog has all sorts of radio trivia. For example, a couple of the latest posts cover a 1920s radio show called Midnight Frolic that ran on WMC in Memphis, TN and the February 1930 issue of Radio News magazine. The latter is available as a PDF for download.
  • This item is from the 9/1/10 ARRL Contest Update: Why is 10.7 used to determine the solar flux index? Spaceweather published this interesting article that explains why.
  • Radio Sky Publishing: Resources for Amateur Radio Astronomers, Students, and Teachers. If you have any interest at all in radio astronomy, check out this website. It’s been very slow for me, though, so be prepared to wait. I’m waiting right now for the “Beginner Tips” page to load.

ITS Launches Telecommunications Science Video Series

Here’s a press release that I received today:

FOR IMMEDIATE RELEASE: August 25, 2010 ?News Media Contact: Moira Vahey at 202-482-0147 or

BOULDER, CO — The Institute for Telecommunication Sciences (ITS), a division of the National Telecommunications and Information Administration (NTIA) of the U.S. Department of Commerce, today released a collection of online training and educational videos for public viewing on ITS’s website. These videos cover telecommunications topics ranging from an easily understandable review of the fundamentals of radio spectrum—such as defining decibels using common logarithms—to in-depth explanations of complex engineering issues like resolving signal-interference problems. 

In announcing the public posting of this video collection, Al Vincent, Director of ITS, stressed that this is the first of what he expects to be a valuable educational series. “The publication of these videos reflects ITS’s goal to be not only a technical resource for telecommunication standards development, but also a trusted, impartial informational resource for industry, students, the general public, and other government organizations,” said Vincent. “This unique web-published video series represents a significant expansion in the accessibility of ITS’s research findings for the public, and we certainly hope to continue to make information on additional topics available in this way.”

ITS provides a variety of useful information and tools on its website, including technical reports, radio propagation data and models, and various ITS-developed software tools. Since its founding over 70 years ago, ITS research has been fundamental to the development of realistic and achievable standards for telecommunication protocols and equipment.

Video presenter Frank Sanders, a physicist and electrical engineer who leads ITS’s Telecommunications Theory Division, regularly authors ITS contributions to the International Telecommunication Union (ITU). The ITU is a United Nations agency that deals with telecommunications and technology issues.

The Institute for Telecommunication Sciences is the research and engineering laboratory of NTIA, which serves as the executive branch agency principally responsible for advising the President on communications and information policies. For more information about ITS, visit the ITS website. For more information about NTIA, visit the NTIA website.

I just watched Episode 15: Resolving RF Interference: RF Frontend Overload Problems, and it provided a very good explanation of front-end overload. Although ITS deals mostly with radar systems operating in the GHZ range, most of the presentation also applies to ham radio systems operating at HF, VHF, and UHF.

One of the things that made this presentation so good, is that Sanders is a very good draftsman. Even though he was moving right along, the graphs that he would draw on his whiteboard were very nicely done, and I think that made the presentation a lot more understandable. That’s a good lesson for all of us ham radio instructors.

Three New Web Resources

Here are a couple of new web resources that I have found out about recently:

  1. The Portable Antenna.This is John, KC8ZTJ’s new blog on his experiments with QRP operation and portable antennas.
  2. W1PID.Com. Jim, W1PID, operates a lot of QRP mobile. This website chronicles many of his adventures, and include a lot of nice pictures, like the one below.
  3. Clip.Com. Break the belt clip on your HT or buy a used one without a clip? Try this website. If they don’t have an exact replacement, you might be able to use one of the generic clips that they sell.

Take Everything With a Grain of Salt

I love the Internet. Heck, I make my living developing websites and producing content that appears on the Internet. And, it’s really a great source of information.

Unfortunately, it can also be a great source of misinformation. What prompts me to say this is a posting that I just ran across on eHow.Com. Titled, “How to Wire a Studio Microphone Cable for the Icom IC 735,” the article purports to tell you how to use a studio microphone with this HF transceiver.

Just about everything written is factually incorrect. For example, the author says:

The Icom IC 735 is a now discontinued HF transceiver designed for home-based radio frequency use. While using the transceiver, one can communicate with other individuals through an attached microphone. The microphone is XLR-based, allowing the user to run a microphone to the standalone receiver via a single XLR cable. To hear the communications, a pair of headphones is inserted into the microphone port on the front of the Icom IC 735.

He got the part about it being discontinued right, but everything else in that paragraph is wrong! I usually just blow off these nonsense postings, but in this case, I just couldn’t let this go.

Perhaps it’s because I have owned several IC-735s in the past and have recommended them to several of my friends, but also because I could imagine some new ham who just purchased an IC-735 at a hamfest somewhere trying to figure out how to connect his microphone to the rig. He reads this article, then goes to the nearest Radio Shack and buys an XLR connector, only to find out it’s not the one he needs. How frustrating!

Fortunately, eHow allows you to flag an article if it has incorrect information. I’ve done this, and I would encourage you to do something similar should you run into the same kind of misinformation on eHow or other websites.

Having said all that, and planting my tongue firmly in my cheek, let me assure you that anything you read here on KB6NU.Com is completely factually correct and you can trust it implicitly.

The New ARRL Website

I recently got an e-mail from a reader who wondered why he was the only one to have commented here on the ARRL’s new website. “Alas,” he asked, “Am I the only user left on the ARRL site, or are all of the new hams simply illiterate and just looking at the pictures, or, are they all only hanging around these days”?

My reply was, “I don’t think that most hams give a hoot about the new ARRL website.”

My take on it is that it’s a fancier design, but it’s not any easier to use than the old one. In fact, in some important ways, it’s more difficult. For example, there used to be links on the home page to the club search and exam search pages. Now, you have to make two or three clicks to get to those pages.

I cruised around the club section a bit and didn’t note any new content there. My gripe about the old website was that the content really needed some updating. In my short foray onto the new site, I’d have to say the same thing. The only thing that the new site adds is a new wrapper. Of course, I have to admit that my brief bit of web-browsing was not very extensive, so this criticism may be unfair.

What do you think? Do you think it was worth all the time and money they spent on it?