A new Radio for my shack

Well, I’ve been getting back into Ham Radio lately. With the pandemic stifling most things that are fun, I figured it would be a good activity for being social distanced. Little did I know which way it would go.

I had a good radio, my main radio, which served me well for over 20 years. I used it in many contests to make thousands of contacts over the years. I didn’t scrimp on it, I spent until it hurt, which at that time was a lot of money. I put all the accessories into it. Over the years, it needed some maintenance. It had a battery that died every ten years or so, and when it turned on and said “TILT” this time, I assumed it was time for a new battery.

I ordered a new battery, a li-ion coin cell. The original was the type that solders directly onto a circuit board. It’s hard to find the exact right one of those, but I ordered a holder as well. I figured I’d put the holder in once and from then on, changing the battery would be a snap.

But I put it all in and it did not fix the problem. I looked into the feasibility of sending it out for repair. I had shipped it to a fellow in Texas once before for work. he was about the only Kenwood certified repairman left. I looked him up and his web site said he had retired. But it referred me to a new service place, up in Minnesota, I believe. They did indeed still service my radio. For only $350. Shipping would be about $50 each way. I looked at the prices of used models of the radio, and they were barely getting $500.

I decided that I have had my money’s worth out of the old radio, the Kenwood TS-850SAT, and it was time to replace it with something new. But I didn’t want to spend the kind of money it would take to replace it with an updated equivalent. That would have taken at least $2-3000.

Kenwood TS-850SAT

Kenwood TS-850SAT

Icom IC-7300

Icom IC-7300

Instead, I lowered my sights a bit and found the Icom IC-7300. it was going for $1100 with a $100 rebate. It’s a modern style radio, a bit smaller th an the old one, but very capable. Many of the extras I had to add to the old radio came built in on it. How do they do that at such a low price? Well, technology. It’s a radio based on DSP – Digital Signal Processing. Most of the work that used to be done by stages of mixers and filters and amplification, is now done by microprocessors.

The 7300 has been on the market for at least 5 years, but I hadn’t been paying attention to it. It still looks like a traditional radio, but with a fancy touch screen that gives you all kinds of menus for settings and different ways to display what it is doing. It also interfaces with your computer, not through a serial port, like the old one did (with a special adapter) but through a USB cable. The computer sees a virtual serial port to control the radio’s frequency and other settings, just like the old radio, but it also acts like a sound card so that the computer has access to sound coming to and from the radio. This greatly simplifies using data modes.

So, I got the new radio and have been having a great time making it work and setting it up. One thing I found, that I already knew, but didn’t matter with a radio that didn’t work, was my antennas have deteriorated to the point of being almost useless. The only one that is even partially useful is my 40 meter vertical and there is something wrong with it, but I can still make some contacts on it. In fact, I’ve been using it on most bands with the tuner built into the radio.

My triband yagi, A Cushcraft A3S, had been out of commission for years. The center, driven element fell off. The U-bolt broke and the whole element came down. I can’t get up there to do anything, so that’s not going to change.

My 80 meter dipole, a high wire antenna that runs from a tree in front of my house to a tree at the back fence, just doesn’t work. All I hear on it is noise. I can see that one end was caught up in some branches and has unravelled, but not fallen down. But there must be something more wrong than that. Maybe the coaxial cable is broken, maybe the balun at the center is bad. It’s held up by ropes that go through pulleys, but the back one won’t let it down because it’s caught up in the tree branches. I’ll have to get up on my kitchen roof and pull the center down by the coax to free it up. But I’m not going to do that until spring.

The 40 meter vertical, I suspect has a bad coax, but I’m not yet 100% sure of that. It’s buried in the ground, and even though it is direct burial cable, that’s only good for so many years. I ran a piece of RG-8X to replace it, just letting it lie on the grass and that improved it somewhat. It’s time to replace the coax in the ground just on principal, but again that will have to wait until spring.

So, I’ve got a nice new radio, but can’t fully enjoy it right away.

Quite possibly the best keyer ever.

Over the years, the quest for a good morse code keyer has been on the mind of many Hams. I remember the first keyer I ever saw at a friends shack while I was still in high school. It was the latest thing with “Iambic” or squeeze keying. He demonstrated using his Brown Brothers paddles how it would alternate making dits and dahs when both paddles were held. It was homebuilt using RTL logic.

Over the years improvements came along. Memories that could store canned messages. Weight and beacon settings. Serial numbers that auto-incremented for contesting. Back before computer logging took over, a good contest keyer was a necessity.

MFJ Grandmaster “contest” keyer

Then contest logging software took over the CW sending and the keyer was on the back shelf for use in casual QSOs or when the logging computer crashed. But eventually, computers got too complicated and too fast and busy doing other things to send decent CW without it getting choppy. Of course, we were demanding more out of the logging computer – controlling two radios, sending/receiving spots over the network, etc.

So along comes K1EL and his Winkeyer. It took all the timing issues away from the main computer and let a little PIC chip handle them. It worked like a charm and became the standard for most contesters. And you could plug a paddle into it and use it as a simple keyer too! I have one and love it.

K1EL WinKeyer

But Hams being Hams, never sit still and other choices came along. Of course, not everyone cared about contesting or they needed a keyer that had other features. A number of people published keyers that used small microcontrollers. The Microchip PIC chips were popular and a number of Hams created keyers using them. The Embedded Research Tick keyers brought them down to a single chip you could embed into your homebrew rig or build into a case. I built one the size of a keyfob for your car.

But eventually, people discovered the Arduino and how easy they were to program. I’m sure many programs were out there and I’ve played with a couple, but the one that has come to the forefront was written by Goody, K3NG. I’m not sure when it was first released, but by now it is quite mature and has an extensive feature list, including incorporating the K1EL Winkeyer2 functionality. It continues to be updated on a regular basis today. You can read about it at https://blog.radioartisan.com/arduino-cw-keyer/

I don’t even remember where I first heard about it, but I know I had played around putting the code into an Uno and making all the connections on a breadboard. But I really got into it when I saw the DJ0MY kit that lets you put it on an Arduino Nano. The Nano is a small Arduino board about the size of a large postage stamp. I had been using Nanos and Minis for some other projects, so I knew what it could do. I ordered the kit from Germany and when it came, I built it. The program gave many options and I had a blast changing things and trying them out.

DJ0MY NanoKeyer

So, it makes a fantastic keyer. I can’t list all the things it can do here because it is too long of a list. Read the link above if you want. But the problem was, there was so many features that they can’t all fit in the limited space in the Nano’s memory. The way Goody wrote the code allows you to turn on or off sections of the code when it gets compiled. You pick and choose the features that you really want and if they fit, you’re golden. If it doesn’t, you have to give something up.

But the code will run on any Arduino. What if there was one that had more program space and could accommodate more features? Well, there is. The Arduino family tree is pretty big, even just the official branches. One stood out as perfect for making the ultimate version of the K3NG keyer. It was the Arduino Mega 2560. It offered more than eight times the program space as well as double the number of I/O pins. The only drawback was it was twice the size of the Uno and completely dwarfs the Nano.

Nonetheless, people started talking about making a PC board, or shield, to make the Mega into a keyer. It was a great idea and some people homebrewed them.

Then someone said “What about these Mega 2560 Mini boards we see on EBay?”

Mega 2560 Pro Mini

Arduino Mega 2560 Pro Mini

Someone had taken the same chip as used in the Arduino Mega 2560 and put it on a much smaller board. All the I/O pins were there, and since it is the same chip, the memory size is the same. It just no longer fits the shield layout that the Uno and Mega share. It ends up being wider than the Nano but not much longer. It’s not official Arduino, but is comaptible with the software. Since the whole Arduino project is open source, they encourage others to develop them. Official, full sized MEGA 2560s are in the $35 range, with imported clones being about $15. The Mega 2560 Pro Mini is under $10 direct from the manufacturer. There are also other similar Mega 2560 reduced size boards out there, but the layout differs slightly.

It was such a good idea, that two groups are developing projects around it simultaneously. K5BCG on the Radioartisan groups.io boards are making a board available. This is the support group for the K3NG keyer code.

At the same time, the CalQRP group (also on groups.io) is making and selling very similar boards. There are differences between the two projects, mostly in displays and interfaces. But both run the K3NG Keyer code and should allow a much more complete set of features to be incorporated at once.

Both projects have published the PCB CAD files, schematics, and full BOMs to make it easy to reproduce.

I was considering picking up a proto shield for the Mega2560 (full size) and building the keyer circuits on it. It would be a feasible project. I have a couple of the Mega boards on hand. But I heard about the Mega-Mini sized boards and decided to wait. I’m glad I did. I’ll end up building one of the above projects for sure.


A project using off-the shelf modules to build an all-in-one Ham Radio interface for digital modes and contesting.

This article is a work in progress. I will continue to update this while it progresses. Photos will be added eventually.?


Item Source Price URL Notes
KF5INZ Easy Digi board (2pcs) Ebay $15.91 https://is.gd/n0cqq7 You get two for this price!  
DIY Prototyping Board PCB (5pcs) Ebay $6.99 https://is.gd/JMeO94   Many sizes available on both Amazon and EBay or elsewhere.
ELEGOO Arduino Nano V3.0 (3pcs) Amazon $13.86 https://is.gd/0JmAlJ   https://blog.radioartisan.com/arduino-cw-keyer/  
AmazonBasics 4-Port USB 2.0 Ultra-Mini Hub Amazon $6.99 https://is.gd/P4HYov    
GearMo USB to serial converter Amazon $16.88 https://is.gd/cejiNb

Win 7,8,10 compatible
CH340 chipset
USB Audio Adapter
(Sound card)
Amazon $6.69 https://is.gd/SgBDQi Any similar adapter will do.
Enclosure Ebay $7.51 https://is.gd/7cHP96 Split Body Extruded Aluminum Box 110*88*38mm

The Plan

I have been thinking about putting together an all-in-one interface box to use with a laptop and my K2 for digital sound card modes as well as some QRP contesting. Looking at the available offerings everything I saw either didn’t do something I wanted, was too expensive, or was too complex – doing many things I didn’t need. I have an old Rigblaster, but it’s not a USB version, so I’d need another USB-serial adapter to use it. Everything just added multiple wires and connections to deal with.

So I started thinking about doing it myself. Rig interface, I already had. With the K2 it’s simple. Just a USB-Serial adapter with a short cable that I built a keying interface into. But I still wanted a Winkeyer for contest CW. I have a Winkey USB, as well as a K3NG Nanokeyer which both do the job well. I had USB sound cards, but not the interface circuits between them and the radio. So I would need to build that up.

So what do I end up with? Rig interface for frequency control – 1 USB port. Contest keyer – 2 USB ports. Sound card interface – 3 USB ports and an interface box. Lots of cables. Three USB ports would nearly fill my laptop. If I use my Surface Pro, it would require a hub. Another box and wires. 

I decided some consolidation would simplify things greatly for portable operation, so the idea of combining all the above into one package was born. I could take inexpensive modules out of their packages and combine them into one complete station interface. That’s the premise of this project and this document is the beginning of it.

Some software is able to use one audio channel to put a pilot tone out that is used to control the radio PTT. Others use DTR or RTS lines. Most contest logging software uses the control lines as well. Some people are using a delay circuit to hold the PTT in. The Winkeyer handles this on its own. I am not sure how I will end up doing the PTT, I may use a combination of these.

The goal of this is to simplify the wiring needed to use digital modes between my K2 and a laptop. Ideally, I want to end up with one USB cable from the laptop to the interface, and one cable and connector from the interface to the K2. The last cable might have multiple plugs that fan out to the rig, but I want the bulk to be one cable and plug into the interface. I’m still considering whether I want to install a dedicated plug at the K2 end, or stick with existing connections. (Mic jack, key jack, speaker jack.)

Module selection and theory

KF5INZ Easy Digi board

I was looking for a design of a simple sound card to radio interface and parts list. Somewhere I came across this neat kit that made it all in one easy purchase that cost less than finding the parts individually. But, even better, you get two.

DIY Prototyping Board

This will be the “motherboard” for all the modules. It will be a common backplane for the modules as well as provide a place for discreet components and connectors, and allow making interconnections neatly. Get one of a generous size. You can always trim it later.


After beginning to lay out the pieces on the proto board, I began to get a feel for how big it was going to end up being. I took some rough dimensions and started to look for an enclosure. I wanted it to be RF tight and liked how my NanoKeyer turned out with an extruded aluminum box, so I looked for something similar. I found a nice box that is 110x88x38mm and ordered it. But to get the spare USB connector to meet up with the end panel, I have to rotate it’s orientation on the protoboard 90 degrees. So, I’m basically taking it all apart and rebuilding it from the start. I’m going to wait until the new USB-serial adapter comes.

Arduino Nano

I selected the Arduino Nano to be the keyer module. I’ve used them before in other projects, including a K3NG Nano Keyer which provides Winkeyer USB functionality for contesting purposes. I have used many Elegoo Arduino products before and have found them to be good quality and work perfectly with the Arduino IDE. Getting the three-pack was just as cheap as buying an individual one. I will have use for the others.

Some incidental circuitry will need to be built for the keyer. I ordered some 1/8” jacks and plugs as well as some opto isolators to complete that. I still need to come up with a speed pot and decide whether I need memory buttons, or just one for command mode. The NanoKeyer has so many features I can’t add them all. Fortunately, I don’t need many of them and I rarely use the internal memories when connected to a computer.

4-Port USB 2.0 Ultra-Mini Hub

Since I am using several USB modules, I wanted to use a hub to combine them and let me use one cable to the computer. Any cheap hub would do as long as it can be removed from its case and integrated into the project. Amazon Basics supplied a generic product that fits the bill at low cost. The unit has three USB jacks on one side and one on the back corner next to the USB cable that comes in. If mechanical considerations permit, I want to have that back connector accessible when it is in a case. The three on the other edge are enough for the things I’m building into the interface and will be removed from the board and hard wired.

USB to Serial Converter

This will provide the rig interface and keying line for the digital modes.

I wanted a USB to serial adapter, and had several on hand, but most of them are made with molded plastic and looked like they were going to be hard to remove the casing. I was going to see if I could pick one up that had a plastic case I could crack open easily, but saw this which I thought should do even better.  It turned out, it only provided TTL levels and even when I tried a little level converter board, did not work with the K2.

I had a Keyspan adapter that the plastic could be opened. I thought about using it and even took it out of its case. I didn’t like the size of it and it was an oblong shape. Even if I trimmed the board after removing the connectors, it would be a kludge. So I looked for something online.

I found a different adapter with a rectangular shape and a case that looks like it will open easily. It also claims to be a FTDI chip so I already have the drivers. I’ll put the connector back on the other board and keep it. It might come in handy for something else.

USB Audio Adapter

I had one on hand, so I did not initially buy one. But the one I had didn’t seem to work. It was a cheap one that I had laying around and I couldn’t seem to get a decent audio level into it. It played back music into headphones and sounded great, but I think the mic input may have gotten fried. So, after a recommendation on e-Ham.net, I ordered the one in the list. It seems to work much better.

Unresolved Issues (So Far)

NanoKeyer. A number of discrete circuits around the Arduino Nano board need to be built. I am waiting until all other layout work is done to finalize this. To get space, I am considering either putting the Nano under the USB hub which is raised on standoffs, or else putting it on the opposite side of the proto board where it would have the whole board.

Update: The Arduino Nano is mounted on the proto board and the associated components installed. Good news is, it works! It’s a pretty bare-bones version of the K3NG keyer program with mostly just a basic keyer and the Winkeyer functions.

PTT circuit. I haven’t decided how I want to go about keying the rig for digital modes. I think this may solve itself by what works. I have choices: RTS/DTR lines from the serial port. A VOX circuit. Or a VOX circuit triggered by a tone on the right audio channel. We’ll see what works best.

USB-serial adapter. I hope the new one I ordered works. Just works.
Update: The new serial-USB adapter came. It was easy to get out of it’s case and the USB cable came off easily and was wired directly to the USB hub. The DB9 connector was not so easy. I couldn’t unsolder it. Since it was soldered to both sides of the board, I couldn’t get the terminals free. I decided to cut it free with a Dremel tool and cutting wheel. That worked, but I slipped and cut a trace. It might not be one that is needed, but I repaired it with a tiny strand of wire.


An interesting interface built into the K2. https://is.gd/Vdf4GO

KIO2 Manual with cable instructions https://is.gd/bx1xzK

FTDI Support Documents https://is.gd/pSYxdV

KD2AVU Soundcard interface https://is.gd/OwVBzX

TrueHamFashion articles on the EasyDigi interface:
https://www.youtube.com/watch?v=VGpfQuorKN0 (video)

UZ7HO Soundmodem (software TNC) https://is.gd/twOsRG

WinLink Express https://winlink.org/WinlinkExpress

DuinoVox rig interface https://is.gd/2hzpPn

W3FPR Fixed Audio Out for the K2 http://www.w3fpr.com/K2_Fixed_Audio_Output.htm

Appendix A: Nano Keyer commands


button 0: command mode / command mode exit
button 0 + left paddle:  increase cw speed
button 0 + right paddle: decrease cw speed
button 1 – 12 hold + left paddle: repeat memory
button 1 – 6 half second hold: switch to TX # 1 – 6

  Command Mode (press button 0 to enter command mode and press again to exit)

A  Switch to Iambic A mode
B  Switch to Iambic B mode
C  Switch to Single Paddle Mode
D  Switch to Ultimatic mode
E  Announce speed
F  Adjust sidetone frequency
G  Switch to bug mode
H  Set weighting and dah to dit ratio to defaults
I  TX enable / disable
J  Dah to dit ratio adjust
K  Toggle Dit and Dah Buffers on and off (Ultimatic)
L  Adjust weighting
N  Toggle paddle reverse
O  Toggle sidetone on / off
P#(#) Program a memory
R####  Set serial number to ####
S  Alphabet code practice (FEATURE_ALPHABET_SEND_PRACTICE)
T  Tune mode
V  Toggle potentiometer active / inactive
W  Change speed
X  Exit command mode (you can also press the command button (button0) to exit)
Y#### Change memory repeat delay to #### mS
Z  Autospace On/Off
#  Play a memory without transmitting
?  Status
         1. Speed in WPM
         2. Keyer Mode (A = Iambic A, B = Iambic B, G = Bug, S = Single Paddle, U = Ultimatic)
         3. Weighting
         4. Dah to Dit Ratio

Strikeout – Does not apply to this configuration

On the relationship between radio and computers.

After my last post, about my 50 years of Hamming, in discussion on Facebook, where I also posted the same thing, several people also confessed their experiences with Ham Radio in their past.

I was fortunate to attend a high school that offered some computer courses then. In the late 60’s computers were big machines usually found at universities or the largest of companies.

A teacher at my school was also an instructor in computer study at a local community college. He taught courses there in the evenings. During the day, along with his duties as a math teacher at my high school, he offered to teach some computer courses. Data Processing and Computer Programming were the very simple names for the two courses. One was the requirement for the other.

Data Processing taught the basics of how machines came to be made that could manipulate numbers. We studied Babbage and Hollerith and looms and computing machines. But mostly, we learned how a keypunch machine and card sorter worked.

The only computer equipment available to a high school then was a keypunch machine and it’s cohort, the card sorting machine.

We spent a lot of time learning how they worked. How the holes in the card translated into letters, numbers and special characters. ASCII data. How different parts of the 80 columns were used for different purposes and that the first few columns were used for a sequence number. You could drop or shuffle a deck of the Hollerith cards and use the card sorter to quickly put them back in sequence.

Of course, this was all necessary to know for the second course, Computer Programming, because your programs were punched onto cards which were taken in the evening to the community college where they could be loaded into the big IBM computer there to run. If they worked, you would get your results back later.

This was the same time where my interest in radio became an interest in Ham Radio. Two fellow students in my class happened to be Ham Radio Operators and when they found out they could communicate secretly in class by tapping or quietly whistling Morse Code, all sorts of shenanigans began.

They decided it would be a cool thing if they could form a school radio club and set about to do so. They found a willing sponsor, our chemistry/physics teacher and we were allowed to meet after school in the lab.

The first thing on the new club’s agenda was to have all the members of the club get their licenses. The two who were already licensed set about tutoring the rest of us. Electronic theory and rules and regulations were pretty straightforward. They were taught from the ARRL license manuals. But the Morse Code had only one way to be taught – practice.

Hand-sent code with a practice oscillator was used starting out simply with only a few letters at a time. The letters were memorized unti you could recognize them quickly enough to write them down before you missed hearing the next one.

We all struggled along, but I don’t recall even one of us getting good enough to pass even the 5 WPM test for the Novice license.

We also put a lot of effort into a club station. Some borrowed equipment was obtained and a dipole antenna was installed on the roof. The center was supported by the chimney of the schools boiler. It was well above the roof of the gym, so it was a pretty decent height. I don’t think much was ever done with the station because none of us ever got our licenses and the two who had them, had their own stations at home. A few demonstration contacts, at most, were made. But the club call WB2EET was born.

So that’s why my roots of both Ham Radio and computers are intertwined. I just read an article about Dr. Leonard Kleinrock a pioneer in the creation of the precursor to the internet. It was about the same time as I was in high school, and there it was, another guy whose interest in radio and crystal sets led him to an interest in computing. This is a quote from the article in PC Mag. Lots more in the article.

Let’s get your backstory now. Your first interest was in radio while at the Bronx High School of Science, right?
Ah, no, it was long before that. I was a typical kid on the streets of New York. I loved gadgets, puzzles, games, and comic books. Inside the Superman centerfold, one day, was a set of instructions which explained how to build a thing called a crystal radio.

Skip to toolbar