Preventing a computer from powering the Raduino

Doug Wilner  finally got around to putting KD8CEC’s outstanding firmware on his V3 µBITX.  When he is not using his rig for other things, he leaves it on rx on WSPR.  He finds using CAT control for band hopping is fantastic.

He did not want power over the USB cable going to the raduino when the rig is otherwise switched off, so he stripped back the insulation on the USB cable, parted the shielding, and like a B movie bomb tech, he cut the red wire.

With a little heat shrink on the cut ends, some copper foil to repair the shielding, and electrical tape to replace the outer jacket it looks good as new…from 100 yards 🙂

This may not be a revolutionary break through but Doug figured it was worth sharing with µBITX constructors.


Sketch for W8TEE Morse code tutor now available to download


The source code and schematic from Jack W8TEE’s FDIM talk on the Morse Code Tutor (MCT) is now available in the Files section on:

SoftwareControlledHamRadio Group.

Please note that there are still some changes that he plans to make to the code, but there are no plans to change the hardware of the MCT.

Al and Jack consider the MCT to be Open Source, subject to the MIT Open Source agreement. (This more-or-less means that you need to leave my headers in the files.)

Note that there are multiple files in the zip file and those files must all appear in the same project directory. There are also some non-standard headers used that are not part of the standard Arduino IDE. The URL for these non-standard headers are given after their #include directives in the MorseTutor.h header file. This is to be expected because the code uses the STM32F103 (“Blue Bill”) microcontroller.

This requires you to install the STM32F patch, and there are plenty of places to find help doing that. I used “Using the Arduino IDE with the STM32F” as my search in DuckDuckGo (I’m done with Google) and found plenty of entries from which to choose, including video and written guides.


Another new uBITx build … from N0KAI

Jeff N0KAI  shows off what he calls his “fun build”.

Mods to his µBITx include the Nextion 4.3″ screen , a 2.5 MHz high-pass filter for BCI,  a Kit Projects AGC board, and fidelity mods to the LM386 amp.

He says that the Uniden CB mic works, but its gain is a bit low, which needs to be fixed. CW, however, works fantastically apparently.

Jeff brought the RF gain control forward to the front panel on a concentric potentiometer with the AF gain control.  He really likes that, but direct soldering shielded cable to the SMT potentiometer pads on the board was a recipe for disaster. Within hours, the ground pad lifted even though he was gentle as hell with it.

Jeff suggests that it would be nice to see a future revision of the Kit Projects AGC board include better solder points or even headers for all the wires, as he tacked header pins to the pads for the switch connections. He notes, however, that the AGC circuit itself works very well.

Jeff concludes by saying “This is gonna be a fun QRP rig for Field Day…”


BITX related on-line websites, facebook pages, and blog sites

Arv K7HKL has compiled a list of BITX related on-line websites, Facebook, and Blog sites on the Internet.

Youtube channels that have useful troubleshooting assistance:

Ashhar Farhan VU2ESE and Hans Summer G0UPL at Dayton Hamvention 2019

Are any µBITx constructors planning to be in Dayton for the 2019 Hamvention?   If so, this is your chance to meet the designer of the µBITx, Ashhar Farhan VU2ESE.

It is suggest that you meet him over dinner and coffee on the Thursday 16 May.  Meet up  outside the Holiday Inn at 7 pm.

Ashhar is bringing with him a new project that combines  an SNA and SWR meter and another one that is ‘something about a raspberry’.

Hans Summers G0UPL of QRP Labs fame will also be at Dayton Hamvention. Hans says, “I will be arriving late Tuesday night. Staying in the Holiday Inn. Will look forward to catching up with you and any other BITXers or QRP Labbers!FYI I will also have with me stock of most of QRP Labs product line, which will be available at vendors’ evening on Thursday, and throughout the hamvention on Friday/Saturday/Sunday at the QRP Labs booth 6612.”

Hans has been working on the new QSX all HF bands transceiver expected out this year.

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.


An interesting µBITx

Daniel Conklin says “I guess I’ve had enough fun with this radio and now it’s time to move on.”

He is selling his UBITX v3 which is built into an Apache case.  It might inspire others to build their rigs into these clamshell like cases.

There is space for the mic and a battery pack to sit when the case is closed. The mic and PTT switch are mounted in an old BaoFeng mic housing and it works well.