ubitx 4 - want a fresh start, need guidance #ubitx #ubitx-help #arduino #raduino #v4

Joe N9OK

Hi, I purchased my v4 in December 2018. The receiver initially seemed to work correctly but no longer does. I suspect I messed up a calibration or inadvertently caused some code-related issue.

What I would like to do is to erase all internal calibrations that may exist, reload stock factory code, and recalibrate. I have the needed test equipment to do this. What I don't have is the knowledge of the ubitx code.

Where can I find a repository containing stock code, along with instructions how to compile and load this code, as well as clear any internal calibrations and recalibrate?

73 Joe N9OK

Joe N9OK

A little more detail: The receiver functions but audio is highly distorted and sensitivity is poor. It seems like the filters are not properly centered. I think I messed up a prior calibration attempt, hence my desire to start over.

Evan Hand


You can start here:
The links to the stock code are there.

Downloading the original firmware will not reset the calibrations.  Those are stored in EEPROM, not program memory.  The best bet is to follow the instruction from Ashhar Farhan for version 6, with the understanding that the version 4 has a different interface and different BFO/SSB crystal frequency.  The process should be very close.  Here is that link:

To point out again, the controls are different, and the BFO frequency is different.  The process to follow is still the same:
1 - Adjust the BFO 
2 - Adjust the frequency
3 - Readjust BFO

Getting to the calibration settings is a multi-step process:
1 - Press the encoder button to go into memory mode
2 - turn to calibration and press the encoder again
3 - press the encoder to go into the menu
4 - turn encoder to get to BFO calibration and press
5 - Adjust BFO with encoder
6 - press PTT button to set
7 - power cycle the rig.

The Frequency calibration is similar to the BFO calibration.

One note, When you go into the calibration settings, the offset values are reset.  This means you are resetting to the "zero" offset each time.  The value is not saved until you press the PTT and power cycle the rig.

Hope this helps.



If indeed a calibration attempt is the cause, no need to refresh your v4 firmware code. Also let's presume the only thing you can easily corrupt there is the calibration.

Use your search engine to find k3pzn ubitx website. Its my local club. Clear instructions on v4 bfo calibration are there. Bfo cal is critical to receiving. Frequency cal does not matter as much except your operating frequency to a minor extent.

Caution is that bfo cal varies between models, hence my suggestion to visit k3pzn. Be patient,  once you adjust this its a huge step.

It would also help to know a bfo cal setting that is a good starting target for v4, can anyone identify this? I can't remember if that is in cal instructions.


Joe N9OK

Evan, thank you very much for your response. It was very helpful. The ubitx is now properly aligned and functioning. Listening to nice, clear audio during the WPX contest. Not as clean as my K3, obviously, but good enough to get the job done, especially considering the cost.

Joe N9OK

Joe N9OK

On Sun, Mar 29, 2020 at 01:57 PM, Curt wrote:
k3pzn ubitx website
Curt, I just saw your response. As you might have seen, I did get mine properly calibrated and operating earlier today. It was a calibration issue. With the stock v4 firmware it's all too easy to inadvertently mess up the BFO freq, and I'm sure that's what happened. I messed it up numerous times today while testing things out. FInally I got smart and wrote the pertinent calibration items on the case I fabricated.
Nice complete website (for your club build).
Thanks and 73,
Joe N9OK

Dexter N Muir

Goes to show just how little progress we make despite all our tech: pen/pencil and paper still
relied on to convey vital information.



      What was the H bracket used for that is mentioned on Carroll County site?



Fantastic news that Joe has his BFO aligned - and a nice rig lives in this assembled item. 

Tom - the H bracket sits onto the main board to hold add-on accessory boards.  I wasn't sure I would use it when I was handed one - but I needed to do some disassembly for some reason - and I installed it.  Let's see if I can remember what is on it: (1) VK3YE AGC home constructed (2) Gordon Gibby relay board to cure harmonic spurious (3) NESCAF audio filter, variable bandwidth -- and maybe someday a speech processor (although I am making some SSB qsos without it). 

one can use stand-offs only - but eventually you might run out of places above the existing screw holes - so now I confess it is handy - if you do 3-D printing I can inquire if we have released the artwork for it. 

I am glad to finally have the lid on the ubitx so I can work some other projects, some ham radio related. 

nice to participate in the world-wide community here - everyone please work to stay well, and enjoy your radiations

Curt wb8yyy


Thanks Curt, I wondered if that was it's purpose. I don't have 3D printing capability, but I do have some 1/4" thick acrylic; a bandsaw; and a drill press. Could you post a picture? Maybe in a new topic. That looks like a handy add on that I have never seen mentioned before.