KB6NU's Ham Radio Blog

KB6NU's Ham Radio Blog

Operating notes: Homebrew keys, callsign fun

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Homebrew cootie key cuts through QRN, QRM

A couple of days ago, I worked a guy who said he was using a homebrew sideswiper, or cootie, key. I looked him up on QRZ.Com, where he featured a photo of his key (see right). After seeing this photo, I tweeted:

Just worked a guy using this homebrew cootie key. It really cuts through the QRM and QRN.

I included the photo in the tweet.

That really caught the eye of my followers. More than two dozen have either liked or commented on it.

Homebrew paddle uses hard disk drive bearing

Last night, I worked a fellow who also noted that he was using a home brew paddle. He said that it was similar, but not exactly like the paddle built by N2HO (shown at left).

The unique thing about this key is that it uses the magnet and bearing from a hard disk drive. I don’t know if or how the magnetic tension is controlled, but I think the design is quite unique.

Callsign fun

In the past week or so, I’ve worked stations with fun callsigns. the first is AI5IN. Joe’s call not only spells a word, but it is palindromic, if you consider the sequence of dits and dahs.

Last night, I worked K5EMI. Bill didn’t mention why he chose this particular call, and I wonder if he knew that EMI is an acronym for electromagnetic interference. I may have to email him about that.

Amateur radio videos: ARRL Foundation, CW Academy, “brain” transplant for the IC-245

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RATPAC: ARRL Foundation

Mike Ritz, W7VO, Northwest Division Director and member of the board of the ARRL Foundation, discusses the foundation and the grants that it makes.

Master Morse Code with CWops

Joe Fischer, AA8TA, headmaster of the CWops’ CW Academy, joins the All Portable Discussion Zone podcast and talks about how to break through the struggles of learning Morse code.

A brain transplant for the ICOM IC-245

The IC-245 is an all-mode 2m transceiver. This video shows how [IMSAI GUY] replaces the microprocessor board in his transceiver with an Arduino Nano-based board to get a little more functionality. There’s also a second video that shows the initial trial of the board.

A Wikipedia for ham radio?

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I and co-author David Sawicki, WA3DS, just finished the Ham Radio Reference. The book contains an extensive glossary of amateur radio terms, as well as some operating aids, Part 97 rules, and technical information. The book is available in both PDF and Kindle versions.

Yesterday, I sent copies to my colleagues at Amateur Radio Digital Communications (ARDC). Rosy, KJ7RYV, our executive director, wrote back:

Dan, this is great! Thank you.

I wonder…what if we made a page on our website that was just a set of links to references like this. It could be helpful, especially for beginners. What do you think?

We had just created a list of other amateur radio resources for internal use, and had a similar thought about putting that list online. I replied:

I had a similar thought about creating an online resource after we created the list of amateur radio resources. Then, it occurred to me that someone had done this before: AC6V.Com. Unfortunately, as is noted on the website, “NOTE: AC6V.com is an archive of Rod/AC6V’s webpages, and is no longer being updated.” Rod became an SK 5 or 6 years ago, and there are lots of dead links and outdated information on the site, and there are a lot of new resources—like this book—that are missing.

Having said that, we could try to set up a “Wikipedia for ham radio.” It would be a lot of work, but if we could recruit a community of editors, then it might be doable.

So, I’m throwing this out there. Do you think it’s worth creating an up-to-date AC6V.Com? Would you be willing to help? Should it be a wiki or perhaps some other kind of website? Let me know here in the comments or email me directly.

From the trade magazines: Impedance matching, AM flutter, DIY AI

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Back to Basics: Impedance Matching By Lou Frenzel, W5LEF

The term “impedance matching” is rather straightforward. It’s simply defined as the process of making one impedance look like another. Frequently, it becomes necessary to match a load impedance to the source or internal impedance of a driving source. A wide variety of components and circuits can be used for impedance matching. This series summarizes the most common impedance-matching techniques.

The entire series is available as a downloadable ebook.

While I’m not sure, I’d guess that something similar happens on 160 meters or even the HF bands….Dan

AM Radio ‘Flutter’

Sometimes I like to listen to a couple of AM radio stations that transmit from southern New Jersey, which is rather far from here on Long Island. Their signals are pretty strong during the daytime but now and then there is a rapid in-and-out fading effect, which sounds very much like a flutter.

I’ve sometimes heard that same effect when listening to shortwave radio and I initially assumed it was an ionosphericphenomenon but now I don’t think so. There seems to be an alternative explanation.

…read the complete article

I haven’t tried these yet, but they look like fun….Dan

Google’s AIY kits offer do-it-yourself artificial intelligence

There’s plenty of low-cost hardware out there feasible for implementing deep learning training and (especially, along with being your likely implementation focus) inference, as well as plenty of open source (translation: free) and low-priced software, some tied to specific silicon and other more generic. Tying the two (hardware and software) together in a glitch-free and otherwise robust manner is the trick; select unwisely and you’ll waste an inordinate amount of time and effort wading through arcane settings and incomplete (and worse: incorrect) documentation, trying to figure out why puzzle pieces that shouldfit together perfectly aren’t.

That’s where Google’s AIY (which stands for “Artificial-Intelligence-Yourself,” a play on DIY, i.e., “Do-It-Yourself) Project Kits come in. They’re targeted at hobbyists and professionals alike: in Google’s own words, “With our maker kits, build intelligent systems that see, speak, and understand.

…read complete article

Amateur radio in the news: Defib donated to radio club, Chickasaw hamfest (video), KI1M SK

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Defib donation for radio club

Transmission is loud and clear between the Bendigo Amateur Radio and Electronics Club and the La Trobe University Student Paramedic Association. The LASPA raised funds for an AED device back in 2019, and finally got the chance to deliver it last Wednesday. BAREC president Neil Patton expressed his thanks to the student paramedics.

“BAREC is extremely grateful to LASPA and for their generous support,” he said. “The arrival of the defibrillator fulfils certain aspects of our strategic plan and it will be of service to BAREC members and visitors to the Bendigo East Hall”.

LASPA Representatives Matilda Henley-Johnstone and Zoe Biggs conducted a CPR training session, providing BAREC members with the skills and knowledge to use the defibrillator, if it was needed.

…read more

Residents learn about amateur radio at Hamfest

CHICKASAW, Ala. (WALA) — The Deep South Amateur Radio Club hosted Hamfest Saturday morning at the J.C. Davis auditorium.  Folks were able to learn how to use a ham radio from operators. There was also a seminar on emergency communications.

…watch video

Peter Cantarra, KI1M, SK

Peter Cantara, age 59, went home to the Lord on November 10, 2021. He was born in Nashua, NH on November 8, 1962 to John E. and Jacqueline R. (Rogers) Cantara. He lived in Hudson for most of his life and was a graduate of Alvirne High School Class of 1980. He was very active in amateur (ham) radio (call sign KI1M) for over 40 years. He held many volunteer positions in the ARRL over the years. He was past president of the NH Amateur Radio Association and past secretary of the Nashua Area Radio Society. Peter was a member of NARS, a life member of ARRL and a 3rd Degree Knight in the Knights of Columbus, council #5162 (Hudson). Prior to his illness, he was employed at Ham Radio Outlet in Salem NH where he was the store manager.

…read more

Nominate someone for the CWops Award for Advancing the Art of CW

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CWops is pleased to announce that it is now accepting nominations for the prestigious CWops  Award for Advancing the Art of CW for the year 2022.

The purpose of the award is to recognize individuals, groups, or organizations that have made the greatest contribution(s) toward advancing the art or practice of radio communications by Morse code.

Criteria

Candidates for the award may be one or more of the following:

  • Authors of publications related to CW
  • CW recruiters, trainers, mentors, coaches and instructors
  • Public advocates of CW
  • Organizers of CW activities
  • Designers and inventors who advance the art or practice of CW
  • Other contributors to the art or practice of CW

Note: The award is not limited to amateur radio operators or their organizations.

Nomination

Nominations may be made by anybody (not limited to CWops members).  Nominations should be emailed to <[email protected]> with a copy to <[email protected]>.  An email confirmation will be sent acknowledging receipt of each nomination.  In order to be considered, a nomination should be received by March 18, 2022 and include:

  • A detailed explanation supporting nominee qualifications according to the above criteria.
  • Name(s) and call sign(s) (if applicable) of nominee(s), and contact information including their postal address(es), email address(es), and telephone number(s).
  • Name, telephone number, email address, and call sign (if applicable) of the person submitting the nomination.

Presentation of Award

A plaque will be presented at the Dayton Hamvention.  If the recipients are not present, it will be sent to them.

Golden anniversary of the microprocessor

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I used to marvel at the changes that occurred during the lifetime of my grandparents. Born in the early 1900s, they saw the rise of the automobile, the invention of radio and television, and our first attempts at computers.

Now, at the age of 66, I’m beginning to marvel at the changes that have occurred during my lifetime. For example, we’ve now reached the 50th anniversary of the microprocessor.

The ad above announces the 4004, 4-bit microprocessor and the 4001 256×8 mask-programmable Read-Only Memory (ROM), the 4002 320-bit Random Access Memory (RAM), and 4003 10-bit shift register. In all, Intel is touting this series of ICs as “a new era of integrated electronics.”

And, indeed, it was. Before this, companies built computers from small-scale integration (SSI) and medium-scale integration (MSI) integrated circuits. Quite often, these were transistor-transistor logic (TTL) chips.

Just to see how far we’ve come, consider that the Intel 4004 had 2,300 transistors. Apple’s new M1 Max processor has more than 57 billion (yes, billion) transistors! This is all just so incredible to me—and I have a degree in electrical engineering.

For more information on the history of the 4004 microprocessor, see Say Happy 50th Birthday to the Microprocessor, Part I by Steven Leibson in Electronic Engineering Journal.

For a second take on the history of the 4004, see Intel 4004 Microprocessor : The first CPU-on-a-chip was a shoestring crash project.

Operating notes: Tell operators when they’re off frequency, working DXpeditions, repeater crawl

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Tell operators when they’re off frequency

Hams can sometimes be hesitant to notify others when their signal isn’t quite up to snuff or when they’re off frequency. After a recent contact, I’ve decided that I’m always going to mention this to someone that I’m in contact with.

What happened is that a station answered my CQ, but he was so far off frequency that I missed his first call. I could see him answer me on the waterfall, but he was outside my passband, which was set to 250 Hz, so I couldn’t hear him. I set my RIT so that I could hear him and sent QRZ?, and when he replied to that I picked him up just fine.

We went through the RST/QTH/name first exchanges, and on my second transmission, I mentioned that he was transmitting about 500 Hz below my frequency. When it was his turn, he thanked me for mentioning that, and said that he was wondering why CQing stations never seemed to hear him. He spent the next couple of transmissions zeroing in on my frequency. Hopefully, he’ll now be heard by stations he’s calling.

Of course, if I’d had my passband set wider, I would have heard him on his first call. That’s my bad, but he will have better success if he zero beats the station he’s calling in the first place.

Working DX on 30m during the contest

A week and a half ago, during the CQ WW CW contest, I got on 30 meters, not wishing to throw myself into the pileups on 20 meters or 40 meters. I was pleasantly surprised to find the 7P8RU DXpedition to Lesotho. And, since all the other CW ops were working the contest, they weren’t getting many takers. I was able to work them on the third call.

After working 7P8RU, I looked around a bit and happened upon the HD8R DXpedition to the Galapagos Islands. I got them on the first call! I already had HD8 in the log, but 7P8 is a new one for me.

Repeater crawl

They guys here in Southeast Michigan do an amusing thing called the Repeater Crawl. On the first Friday of every month, a group of operators congregate on the General Motors repeater on 443.075 MHz (123Hz PL), which has the best coverage of any repeater in the Detroit area and then set out to see how many of the other repeaters the folks in the group can hit.

I happened to be in the shack with my VHF/UHF radio on when they turned their antennas towards Ann Arbor. I was hoping that they’d call for local checkins, but was disappointed when they did not.

In any event, I think that this is a great activity. If you live in an area with several repeaters, you should consider setting up a “crawl” where you live.

 

Book for professional engineers helps amateurs be more successful, too

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I’m going to steal an idea from my friend, Steve Leibson. He recently wrote a book review of Designing Electronics That Work by Hunter Scott, and I found the book so good that I thought I’d write a review of my own. TL;DR: This is a great book, and what makes it even greater is that the PDF version is free. (Print copies are available for $39.)

As Scott says in the preface, “This book is a collection of tips, techniques, and tricks that generally take a small amount of time and effort to implement, but have a disproportionate effect on the outcome of a design.”

Here’s an RF example:

High-speed and RF signals require high Q (quality factor) capacitors. Capacitor manufacturers have specific product lines for high frequency use. If you use a regular, non-high Q capacitor, bad things will happen: your filters won’t have the response you expect, your amplifiers will oscillate, and you’ll see very high insertion loss through your capacitors. It is critical that you choose capacitors that are rated for the frequency that you’re using. The GJM capacitor series by Murata (their high Q series) has a self-resonant frequency of 16 GHz. Johanson is another good manufacturer of high Q capacitors.

The book is chockfull of such examples on all phases of product design. He starts with how to set product requirements and specifications, how to specify and buy parts, how to build prototypes, keeping a lab notebook, how to design a schematic, how to layout a PC board, and how to test and troubleshoot designs.

There’s also a chapter on how to outfit an electronics lab. Here’s an excerpt from that chapter:

A lab needs excellent lighting. Get ring lights for your microscopes and very bright overhead lights for the lab bench. When you’re dealing with parts that are hundredths of an inch long, you don’t want any shadows. You also want the light to be as white as possible to make discolorations of parts easier to see.

Scott wrote this book for professional electronics design engineers, but nearly all of the advice is applicable to amateur radio. Amateurs may not have to be as rigorous as professional engineers, but adopting some of the practices described in this book will help hams be more successful when designing and building your own projects.

QSLs: KB5EBB, W2AEW

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Normally, I only post QSLs from stations whose call signs spell words. I’m breaking that rule today because the first card is from W2AEW, Tek application engineer, YouTuber, and all-around ham radio celebrity. As you can see, his QSL card shows a screen shot of a Tek scope displaying his call sign.

He writes, “Our first QSO certainly warrants a QSL card.” TNX, OM!

When I first saw KB5EBB’s QSL, I was puzzled about the picture on the front. Well, as it turns out, it’s Phil’s original artwork! He writes, “Haha! I hadn’t thought of my call as spelling a word.”