W8TEE Morse tutor

Jack W8TEE, a keen µBITx builder and co-designer of the JackAl board,  is giving a presentation at FDIM (in advance of Dayton Hamvention) this year on his new Morse Tutor project.  He will no doubt publish his arduino code and schematic after the talk on 16th May 2019.

He has, however, given us his Bill of Materials so that those wanted to get a jump on ordering parts could do so.


JackAl revised wiring harness instructions

Jack W8TEE has taken a number of steps back and reexamined the documentation for the JackAl wiring harness .   You can access the new instructions for assembling the harness by clicking on the reference link below.  Al has added a bunch of new photos to go with the written instructions.  Hopefully constructors will find the instructions to be much clearer.


Caution for JackAl Board owners

Jack, W8TEE and Al, AC8GY produce the JackAl Board add on for the µBITx.  They are warning that two JackAl owners have reported that a voltage spike destroyed their RA8875 display.

Al has looked into this and found that there is a very narrow voltage window on the display. Buydisplay confirms that 4V on the 3.3V line can ruin the display. From what we can determine, voltage spikes were the culprit in both cases.

What the JackAl team is doing is creating a very small PCB that will clamp the supply voltage to the display. Parts for the board will cost less than $2.

They will send one of these PCB boards to JackAl owners at no charge with a request and a SASE.

Further details will be provided when the boards come in.  Jack and Al are also expanding the documentation and hope to have a new assembly manual shortly.  Announcements will be made on the BITX20 IO Groups list and this article will be updated accordingly.


Source code for JackAl

The source code for JackAl is now available for download at our web site, hamradiodesigns.com. I apologize for the delay and that delay is totally on me. Al had his work done months ago. In my defense, it not easy to get 11,000+ lines of C/C++ code to play nice with each other. That said, we think the final result is worth the wait, with features we think everyone will appreciate.

Some details:

There are multiple files in the project. Only one file has a secondary file name of INO. This file contains the setup() and loop() functions and, therefore, all program control elements start in the INO file. All other files are CPP (i.e., C++) files. While this is different than some of you are used to, it brings two advantages to the party: 1) it allows for type checking across files, and 2) it allows for incremental compiles. This second feature can be a real time saver. Instead of compiling almost 400K of source code spread out over 19 files, incremental compiling causes the IDE to only compile those files that have been changed since the last compile.

Line number 4 in the JackAl.h header file contains this line:

  #define DEBUG

In setup(), you’ll see

#ifdef DEBUG



In a few places you will also find:

#ifdef DEBUG

   Serial.print(“x = “);



If you leave line 4 in the header file unchanged, the Serial object is compiled into the code which can be useful for debugging, like the Serial.print() lines above. If you comment out line 4, the Serial object is NOT compiled into your program, and all of the subsequent debug print statements are also not compiled into the program. This technique is called “scaffolding” and it allows you to “remove” debug statements without actually removing them from the code. Because you don’t have to retype your debug statements in the highly unlikely event your changes have a bug in them. This can be a real timesaver. You decide what to do with line 4.

Even if you’ve never programmed, you will eventually get tired of seeing Al’s and my names on the Splash screen. The Splash() function is in the INO file and feel free to change it to your own name and call. Note if you want to change something, you must have installed the Arduino IDE and the Teensyduino patch. Details are in manuals.

This code is Open Source, as is the hardware. This is an experimenters platform and we hope you will do just that. That said, we ask that you leave the file header comments unchanged and at the top of the file. Feel free to add whatever you wish after our comments.

There is a JackAl group now (https://groups.io/g/JackAl) and all comments, questions, and support will be done via that Forum. Please check the site from time-to-time, as we know we want to improve a number of things in the software.

Jack, W8TEE



Jackal Board for the uBITx released

Jack, W8TEE and Al, AC8GY have announced that QRP Guys is ready to take orders for the JackAl support board for the µBITX. A link to a list of its feature set, a video of it in action, and some photos can be seen at


Note that the AGC implements both audio and IF AGC. The appendix to the manual shows a plot of its characteristics. DSP filters are available, including user-defined filters (CUST in figure below). A CW keyer and decoder are also included. The main screen looks like this:

The decoded CW can be seen along the bottom. (In all honesty, that is a guy sending almost perfect code at about 22wpm.  Jack is still playing with the decoder and expects some really smart user to make it much better. It’s got real possibilities as it is based on the FFT bin counts.)

QRP Guys is offering the JackAl board for $40 for the first 50 boards.

After those are gone, the price will be $50.

Shipping in the CONUS is $5 and DX is $15. This is what the JackAl board you’ll get looks like:

The board has all of the SMD’s mounted (including the Si5351 and the display buffer IC). The user does have to supply additional parts: A Teensy 3.6 and associated audio board (both from PJRC.com) and either a 5″ or 7″ TFT touch screen display (BuyDIsplay.com). You should also consider case size when you select your display size. (Note: BuyDisplay.com has actual sizes for each display and they are measured like a TV, so the case can be smaller than you think.)  If addition, there are some IC’s, connectors, audio isolation xfmrs, and header pins that most of you will want to add. The cost of these additional parts should be less than $15 depending on your junk box. The board with these in place looks like this:

The connectors are not required but, since you are also give about a dozen free I/O pins for experimenting, you may want to add them. (The yellow pins above are test points.)

The assembly manual can also be found on the website.

This is an intermediate to advanced semi-kit project. Our intention is to not only give the µBITX additional capability, but to serve as a platform for experimentation, which we hope you will share with the rest of us. You will have approximately 700K of flash and 200K of SRAM free for your inventive side to exploit.

Al and Jack already have some (software) extensions we want to implement. Note JackAl does NOT fix the harmonic or spur issues. However, our test µBITX’s right out of the box were well within spec for 80 and 40 meters and spot on for 20M (15M and 10M, not so much). If you have doubts about your µBITX, check it out. It could well be that your favorite band is within spec. If you don’t have a spectrum analyzer, check with members of your club or the physics department of your local high school,. junior college, or university. Most will be glad to help.

You need to provide your own Teensy.  The reason for ordering a Teensy without pins is that you will need to use header sockets with long pins on the Teensy so that the Audio shield can plug into the Teensy and the Teensy plug into the JackAl board. The Teensy pins do not have the header sockets and are difficult to change without damaging the Teensy.

Note that the power jumper on the bottom of the Teensy 3.6 also has to be cut.


Video on the JackAl system

Jack W8TEE and Al AC8GY have been working on a display replacement for the µBITX for quite some time. They now have a preview video that gives an overview of the JackAl system.

There are some software hiccups in the preview that should be fixed soon. We just sent Rev 4.0 of the JackAl board off to the PCB fabricator.  They hope that this will be the final version of the board. All SMD’s will be included on the board.

JackAl makes use of either 5″ or 7″ 800×480 displays (US$34-$44) using the Teensy 3.6 microcontroller (US$30) and its companion audio board (US$14) for the DSP.

The Teensy has 1Mb of flash memory and 256K of SRAM, or which they are using less than 20% and 15%, respectively.  Jack and Al have also brought out a dozen “empty” pins for experimentation, so along with the I/O pins, there plenty of resources left to play with.

Pay particular attention to the ALS Tuning it uses. It really makes it so much easier to zero in on a station. Details are all in the video.


Getting prepared for the JackAl

Some of you are waiting with baited breath for the JackAl Board, announced by Jack W8TEE.   You can get yourself geared up for the JackAl by pre-purchasing some of the kit required, as it is due to be released shortly.  You will need a colour touch display panel, a Teensy 3.6 processor and associated Teensy audio board.

Display panel

There are two display options for the JackAl board: 5″ or 7″.  Neither is likely to fit in your existing µBITx enclosure, so you may also want to purchase a new enclosure.

The panels can be purchased from BuyDisplay.com. Their order numbers are:

ER-TFTM050-3 (5″)
ER-TFTM070-5 (7″)

Both displays use the following options:

4-wire SPI interface
Resistive touch
No font (the library is being used for fonts)

Both are 800×480 displays using the RA8875 chip. If you run the samples using a touch screen, make sure you run the Calibration sample program first.

Teensy 3.6 and audio board

The Teensy 3.6 and its associated audio board can be purchased from the manufacturer’s website or from other sources.


JackAl Board

Now you can have a look at a partially populated JackAl board thanks to this photo from Jack W8TEE in response to a question about a LA4425 as a replacement to the TDA2822.

The highlighted square in green is the audio amp stage of the JackAl board: a 7W TDA7266M.  Seems like you could really blast the neighbours with that one!

In case you haven’t figured out what the JackAl board is about: it is a supplementary board that hsould be released in the next few weeks by Jack and Al, that adds a Teensy 3.6 processor, and a number of other mods, all on one board.  The Teensy will give the µBITx new features like DSP.

Display your callsign a bit longer in KD8CEC Firmware

 Jack W8TEE tells you how to make the callsign/version number appear for longer on boot up of KD8CEC firmware:
Near line 1200 in setup(), you will find code similar to:
  if (userCallsignLength > 0 && ((userCallsignLength & 0x80) == 0x80)) {
userCallsignLength = userCallsignLength & 0x7F;
printLineFromEEPRom(0, 0, 0, userCallsignLength -1, 0); //eeprom to lcd use offset (USER_CALLSIGN_DAT)
    delay(2000UL);        // Increase from 500
else {
printLineF(0, F(“uBITX v0.20”));
delay(2000UL);        // Increase from 500
The line in blue text will increase the delay time from a half second to two seconds.