Summer ’22 Projects – Part 2 (HAM)

The big project this summer has been advancing my skills in amateur radio. After my Christmas visit to my family last year, I caught Dad’s amateur radio bug (fortunately, I didn’t catch any COVID bug). I obtained my general license in February and was able to pick up a used Kenwood TS-570S radio. After drilling a few holes in my office wall and tossing fishing line into nearby trees, I was up and running with an antenna that will tune to all the amateur bands (more or less).

I’ve already documented some of my early summer adventures like building a key for Morse code operation and having fun sending QSL cards. I finished off the summer with a trip back to my parents and an opportunity to do some combo work.

Combining HAM and Chemistry puns? What’s not to like?
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CW Contact

So I’ve been learning Morse Code throughout the summer and felt comfortable (or daring) enough to try my hand at making some contacts. Now, when I acquired my radio (a 2nd hand Kenwood TS-570S that is treating me real nice), it didn’t come with a paddle or key, so I decided to make my own.

My DIY paddle
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QSL

Note: I realized I made some mistakes on my QSL cards, which might be important for those who are working towards awards. If you happen to be one of them, leave a comment and I’ll get a card with the proper info to you soon. I’ve had lots of irons in the fire the past few months which means little time to actually post about it. Last night, I was able to hop on to my first amateur radio net hosted by the 3905 century club. A net – I learned – is an on-the-air gathering of ham operators, and this one was intended for making contacts with operators in other states. Apparently – and I don’t know all the ‘rules’ – operators get extra points for making contact with a noob (can we use [inter]net lingo with the [amateur radio]net?). I turned out to be very busy with 17 contacts from 12 different states.

First batch of QSL cards to send out.

Conditions were good for 40-m. Earlier in the summer, I tried to make contact with my Dad (WA1ITU) in RI and we were barely able to hear one another. It also helped that I was able to get a new antenna (23-m end fed wire with a coil) tossed into the highest trees surrounding my property and I recently visited my Dad and helped him tweak his antennas (yes, plural). In any case, we could hear each other loud and clear (59) and apparently, a good number of other operators could hear me as well.

If you look closely, you’ll see that the cards have different stamps on them. My grandfather passed recently, and we inherited a chunk of his vast stamp collection. My wife decided to match the operator’s home state with a relevant state stamp (we have a bunch of those). Sending out the QSL cards gives us an opportunity to share in one another’s hobbies. If you’re on the receiving end of one of those cards, and you happened to notice the stamps, let me know!

So, I’m hooked on another hobby. Not sure when I’ll find time to actually do work. If someone is willing to pay me to retire early, please leave message in the comments.

I have the power

Today’s task – because 16 inches of snow fell in the last 24 hours – was to work on the power supply for my homebrew radio. I’ve got a bunch of LM317 regulators lying around so I decided to use one of them. Needed to play around with multiple resistors to get the right settings (12 V in, 5.2 V out). Predicted output was 5.12 V based on the resistor values used, actual was 5.18 V.

And just in case you didn’t believe me about the snow, here’s my backyard:

Such a ham

It seems that I often look for ways to procrastinate from preparing for classes, and this semester is no different. Well, it is different in the sense that to delay my writing exams, I took an exam. Yesterday, I passed the the examination for the amateur radio technician class license.

Soon, I’ll be able to start transmitting in a few amateur bands (one has to wait until a call sign is designated by the FCC and that information is published in their database. Meanwhile, I am keeping myself busy with building a radio. There are plenty of instructions on the web, and the biggest challenge has been poring through all of the available designs and identifying a build that works for me.

For my first build, I want a technician class device that can do both voice (SSB) and Morse code (CW). That means I will need to focus on the 10 meter band, since that is the only set of frequencies where technicians can transmit both SSB and CW. It’s not used nearly as much as the 20 and 40 meter bands used by general class operators, in part due to the limited long-distance (DX) communications possible. That may change, though, with solar cycle 25. Solar activity interacts with Earth’s atmosphere such that HF frequencies (between 3 and 30 MHz) tend to propagate farther. With sunspot activity expected until about 2030, it seems to be a great time to advocate for DIY 10 meter band radios.

I’m a long way from building a complete device (or even really talking about it), but I’ll share a teaser.

Technically, it works … barely.

That’s an Adafruit M4 Express in concert with a Si5351 frequency generator, SA612 mixer, a class D amplifier and a rotary encoder for tuning. Once I connected it to an antenna, I was able to dial into an amateur frequency in the 40-m band (note – anyone can build and use a receiver, the license is required only for transmitting) and hear a ham in nearby Rochester. Pretty exciting for me given that there’s no filter or amplifier on the antenna, which in this case was just a long coax cable.

And so it begins! I’m sure the rest of the semester will be filled with last minute lecture preps and piles of ungraded lab reports on my desk. I’ll gripe about them with anyone who wants to listen in on 10 meters.