Speakers for my Elecraft KX3

Want speakers for your rig? No need to wait. For about the cost of a tank of gas, you could be sitting back and enjoying armchair copy.

The internal speaker in my KX3 is good but not great, plus the rig has stereo effects which you can’t hear through the single speaker. The headphone jack provides 100 mW per channel, which is not enough to drive speakers to a reasonable listening level.

This is my under $35 setup for an external audio amp and stereo speakers. Of course it would work for any other rig.

The KX3 has stereo output, so this is a 15 Watt per channel stereo amp that runs off 12 V, plus a pair of simple 3 inch speakers. The amp is mounted on top of one of the speakers with 2 inch wide velcro. The power lead has Anderson PowerPoles, so it plugs into the rest of my station power bus.

IMG 0221

Let’s walk through the parts list. You can choose your own speakers, of course. I was looking for some vintage Radio Shack Optimus Pro-X44AV speakers on eBay, but ran out of time before JOTA last October. I have one of those speakers on my Lowe HF-150 Europa.

The Pyle speakers are compact, inexpensive, and sound fine. I’m sure there are lots of other small speakers that work.

Item Cost
Pyle Home PCB3BK 3-Inch Cube Speakers, Pair 21.38
DROK Audio Amplifier (TDA7297 15W+15W) 8.50
Velcro 2″ by 4″ strips (optional) 2.77
Belkin Rockstar Headphone Splitter (optional) 10.99
Speaker/power wire had it
Anderson PowerPoles had it

The DROK stereo amp varies in price on Amazon, sometimes around $8, sometimes around $11. It is built around a TDA 7297 integrated amplifier. It works with a DC power supply from 6.5 V to 18 V, perfect for ham use. In small quantities, the IC is under $4. Add in the heat sink, board, pot, and connectors, and even $12 is a fair price. It is a pretty cute little amp, really.

A separate volume control for the speakers is handy. I can turn those up or down as I’m in, or not in, the “shack” (our bedroom).

The blue “power on” LED is very bright, so it is normally taped over with some black photo darkroom masking tape. I removed that for these photos.

stereo speakers and audio amp

I also use a headphone splitter so I can leave everything plugged in—my headphones (Yamaha CM500), the amp for the speakers, and the USB audio A/D device (not plugged in for this photo).

Belkin Rockstar Headphone Splitter

Here is the velcro that I used to mount the amp on top of a speaker. I have extra for other stuff that needs stuck down. The next candidate is my MFJ UTC clock. After that, who knows? I have plenty of velcro left.

two inch wide adhesive Velcro

Finally, here is the whole grand setup in the shack. Such as it is.

KX3 station with speakers

SOTA at Philmont

There are thirteen summits inside Philmont Scout Ranch that are listed in the Summits on the Air (SOTA) amateur radio program. There are another three within the Valle Vidal region to the north of the ranch. Only two of these sixteen peaks have been activated by SOTA operators, Baldy Mountain and Shaefers Peak.

SOTA is an award scheme for radio amateurs that encourages portable operation in mountainous areas. I think it is a great match for Scouting, combining the outdoors, technology, and world fellowship. Grab a radio, hike to the top of a mountain, and talk to people.

Here is a map of the Philmont South Country, which has most of the SOTA summits.

Philmont SOTA South

Starting at the north and moving south, these are the SOTA summits. If the summit does not have an official name, SOTA uses the altitude. An unnamed summit that is 8820 feet tall will be “Point 8820”.

Philmont Region Summit Name SOTA Reference Number of Activations
Valle Vidal Little Costilla Peak W5N/CM-001 0
Valle Vidal Ash Mountain South W5N/CM-005 0
Valle Vidal Point 11100 W5N/CM-007 0
North Country Baldy Mountain W5N/CM-002 2
North Country Point 8820 W5N/CM-023 0
South Country Point 8988 W5N/CM-018 0
South Country Phillips Mount W5N/CM-004 0
South Country Bear Mountain W5N/CM-011 0
South Country Schaefers Peak W5N/CM-016 3
South Country Black Mountain W5N/CM-010 0
South Country Garcia Peak W5N/CM-009 0
South Country Point 8881 W5N/CM-021 0
South Country Mesa Urraca W5N/CM-026 0
South Country Train Peak W5N/CM-013 0
South Country Burn Peak W5N/CM-014 0
South Country Lookout Peak W5N/CM-015 0

I used CalTopo.com to make maps with the Philmont boundaries and the SOTA peaks overlaid. CalTopo is a fantastic, free tool for making custom maps. For a modest subscription ($20/year), you can unlock more features. But the free version is still very useful.

The PDF maps are geospatial PDFs, so you can use them with a mapping app like Avenza Maps (free).

  • Map of all of Philmont with SOTA peaks, in PDF, JPEG, and on CalTopo.
  • Map of the Valle Vidal with SOTA peaks, in PDF and JPEG.
  • Map of Philmont North Country with SOTA peaks, in PDF and JPEG.
  • Map of Philmont South Country with SOTA peaks, in PDF and JPEG.

I don’t have a ride this year, but I want to go back to Philmont, with a radio!

Short Podcasts for the Beginning Ham

Since 2011, Onno (VK6FLAB) has been producing weekly podcasts for beginning Australian amateur radio operators. The podcasts are short, from one to three minutes long. I’m no longer a beginner, but I really enjoy the podcasts. They are full of curiosity, advice, and encouragement. They make me want to get on the air.

The first series of podcasts, What use is an F-call? ran from 2011 through June 2015. These were about operating with with the Australian Foundation Licence, the entry-level license there.

The second series, Foundations of Amateur Radio, is still for Foundation Licence holders, but has a name that makes a bit more sense to non-Australian hams.

Each podcast has a text transcription, which helps with handicapped accessibility. Those are available on the website and I can see them in my iOS Podcasts app.

There are a few terms unique to Australia and amateur radio there, so I’ve compiled a short glossary.

  • The ACMA is the government agency that issues amateur radio licenses.
  • An F-call is an Australian call sign with a four-letter suffix starting with “F”, like “VK6FLAB”. All Foundation Licence holders have F-calls.
  • The Foundation Licence is the entry level amateur radio license. Unlike the US Technician license, it allows operating on HF bands (80, 40, 15, and 10) with voice and Morse at 10 Watts. It does not permit data modes, homebuilt transmitters, or automatically controlled transmitters. Other license classes are Standard and Advanced.
  • Holden is the Australian arm of General Motors, so a “Holden vs Ford discussion” is like a Chevy vs Ford discussion.
  • The LCD (Licence Conditions Determination) is the set of rules and regulations for amateur radio operators.
  • The WIA (Wireless Institute of Australia) is the national association for amateur radio, similar to the ARRL in the US.

Whenever I start one of Onno’s podcasts, I listen to three or four. I’ve listened to over eighty so far and I think I’ll be sad when I finish the backlog and have to wait a whole week for the next one.

Building a Dummy Load

If you plan to transmit on your radio, you need a way to test your transmitter without radiating a signal. You do that by transmitting into a “dummy load”. I had a 20 Watt dummy load, but I needed one to handle 100 Watts, so I built a $40 kit in June. This was the first serious soldering I had done in years, maybe decades.

I built the Oak Hills Research RFL-100 kit. A pre-built 100 W dummy load is usually $150-200. This kit is $40.

The dummy load is twenty 5 W resistors in parallel. Here are the first two resistors, ready to be soldered.

Dummy load 1

And here we are, with half of the resistors soldered onto the board.

Dummy load 2

Here we see all the resistors soldered, the board installed in the nice enclosure, and soldered to the the input connector. I chose a BNC connector instead of the standard UHF connector. My ham shack is cabled with BNC. The enclosure is marked up under the connector mounting nuts because I ground off the paint with a Dremel tool. That was much easier than sanding the paint off.

Dummy load 3

Is it 50 Ω? Well, let’s see. Hmm 49.9 Ω is within 0.1%. My Ohmmeter is accurate to +/-0.5%, so I’ll take that as a solid 50 Ω.

Dummy load 4

Finally, let’s connect it to my new 100 Watt power amplifier on the ANT 2 port. Looks great, handling 100 Watts continuous with a 1:1 SWR.

Dummy load 5

If you have a transmitter and need a dummy load, I highly recommend building the Oak Hills Research RFL-100.

International Radio Scouting Badges

Radio Scouting is an international activity, and the World Organization of the Scout Movement (WOSM) has patches and pins for it. I love the classic design, and I also love the price, with the current exchange rate.

The WOSM Radio Scouting emblem looks a lot like the World Scout Crest, but with a radio twist. It has the same purple background, but instead of the circling rope, it has dots, like Morse Code. The fleur-de-lis is at the bottom, and the center is a globe with headphones, a neckerchief, and some lightning bolt lines. It sounds complicated, but it says “Scouts on the radio around the world” without using words.

Radio Scouting patch Radio scouting pin

Right now (late 2016), the cloth badge (patch) is $1.29 (£1.04) and the metal badge (pin) is $1.81 (£1.46). You can work out the shipping cost yourself, but I think it is worth it to wear the world-wide symbol of Radio Scouting.

Send your name in Morse code!

This sounds like great fun for Boy Scouts or any youth-oriented radio activity. Here is the description from Dan Romanchik’s blog (kb6nu.com) about teaching Morse at the Ann Arbor Mini Maker Faire.

As usual, I had my collection of keys and was teaching kids (and some adults) how to send their names in Morse Code. I have a chart of the characters (see right) that I tape to the table next to the key, and when someone approaches the table, I ask if they’d like to learn to send their name in Morse Code, and if they say yes, I ask them to tell me the first letter in their name.

After they tell me, I show them the character on the chart and then show them how to send it. Once they’ve successfully done that, I tell them to look up the rest of the letters and then send them as well. If they successfully do this, I thrust out my hand and say, “Nice to meet you, Joe (or whatever name they just sent me).” The look on some faces is priceless.

I love the way this goes straight to “do” with a minimum of “tell”, then gives an immediate reward. The “tell me the first letter” method is really clever and makes it almost like a magic trick. You can also manage several people at the activity, as long as you can copy very slow Morse.

Send your name in morse code

Chart in PDF and in Microsoft Word formats.

Quoted with the kind permission of KB6NU.

Update: Don mentioned two things that make it simpler for the participants. First is to use “dit” and “dah” instead of dots and dashes, to start them on sound instead of pictures. Second is to leave off the numbers, since few people have numbers in their names. I’ve updated the chart to follow his excellent advice.

History of Morse Code in the Boy Scouts

Morse code has been in and out of the Boy Scout requirements for nearly a hundred years. During that time, Morse has changed from a career skill to a rewarding hobby, from a vocation to an avocation. Also, radio has grown to include voice communications, data communications, and broadcast.

Morse interpreter strip

I’ve gathered all the requirements I could find: rank, merit badge, or skill award. For context, I’ve included a few historical milestones from amateur radio and from digital and voice communication.

1910: Boy Scouts of America founded.

1912: First amateur radio licenses in the US.

1916: First regular radio broadcasts in the US.

1918: Wireless merit badge introduced, requires Morse at ten words per minute.

1930: Radio merit badge (replacement for Wireless) lowers the requirement to five words per minute.

1937: First Class requirement 4: “Send and receive by Semaphore Code, including conventional signs, thirty letters per minute; or by the General Service Code (International Morse), sixteen letters per minute, including conventional signs; or by Indian Sign Language Code, thirty signs per minute; or by the Manual Alphabet for the Deaf, thirteen letters per minute.” [In Morse, this is about three words per minute.]

1947: First amateur radio contacts over SSB at Stanford University.

1965: First Class requirement 4: “Send and receive a message of at least 20 words, using either international Morse or semaphore codes and necessary procedure signals.” [No speed requirement]

1965: An amateur radio license is accepted as proof of Morse competence for Radio merit badge.

1967: Viterbi decoder invented, beginning of modern digital communication.

1972: First Class drops Morse requirement.

1979: Morse returns as an option for the Communications Skill Award: “Signal by two of the following methods: silent Scout signals, manual alphabet, sign language for the deaf, Indian sign language, sports signals, Morse code, semaphore code, Scouts trail signs.” [This long list of options requires fourteen pages of documentation in the Handbook. Oddly, the handbook includes the Braille alphabet, though it is not one of the signaling systems listed in the requirement.]

1981: Space Shuttle STS-1 mission uses digital voice communication.

1984: Broadcast and SWL options added to Radio Merit Badge requirements, Morse dropped.

1990: First Class drops Morse requirement (again).

1991: FCC introduces no-code Technician license.

1999: Morse replaced by satellite for global maritime distress calls (no more SOS).

2007: FCC drops Morse requirement for all amateur licenses.

2010: Morse returns for one year in the centennial Signaling merit badge with three requirements around Morse.

2012: BSA adds Morse interpreter strip.

2015: Morse returns yet again as part of the Signs, Signals, and Codes merit badge: “Send or receive a message of six to ten words using Morse code.” [No speed requirement]

There are probably many choices for the beginning of modern digital communication. I chose the invention of the Viterbi decoder, because that supported low-latency error correction in hardware for digital codes. And it is really cool technology.

All the BSA requirements after 1965 are from my bookshelf. The 1937 First Class requirement is from the 1937 Scoutmaster’s Handbook. The remainder are from on-line resources.