Firmware : transmits band limits

Pierre Guillot <jc_glt@...>

Is it possible to set limits in the firmware to prohibit transmission outside of ham bands limits as some countries like Thailand do not authorize the use of transceivers which can transmit outside of the ham bands. For exemple 80m goes from 3.5 to 3.6Mhz and 40m from 7.0 to 7.2Mhz, the other bands being more usual.

Re: First HF radio..incensed a week ago...I think I blew up my uBitXv4.

Allen Hundley

I just got some encoders and arduinks today. I replaced the encoder cigar. I replaced the arduino and everything works.

Anyone know exactly what happened there?

On Sep 26, 2020, at 3:43 AM, Evan Hand <elhandjr@...> wrote:
The encoder output is a switch that connects the Black or Brown wire (Encoder input A or B) to the Yellow wire (ground).  So most of the time the value will be high, and only briefly go low when the switch pulses it low.  You can test the Nano I/O with your sketch.  On the encoder short each of the leads to digital ground (the Yellow wire).  The value should change from a high value to a low value when you short it to the Yellow wire.  If you do get the high and low values, then you might have a bad encoder.  The previous does assume that your change to the sketch is directly reading the A0 and A1 analog inputs.

I would suggest that you go back and very carefully verify that you have wired the rig correctly.  You can also compare with this original wire-up from HFSignals:

I still believe that you have a wiring issue.  It is too easy to cross wire the audio and digital connectors, as they both use the same wire colors.  You could also have a bad/loose connector wire.  The pins can get pushed out such that they do not connect to the header properly.

The less likely fault is a bad encoder.  The encoder uses switches, not electronic devices, so not very likely to fail unless there was a high current across them.

Re: Bare end mini usb

Shirley Dulcey KE1L

I've never seen a cable like that, although somebody may sell one. The easiest thing is probably to take a Mini USB cable, cut off whatever connector is at the other end, and separate and strip the wires.

On Sun, Sep 27, 2020 at 8:46 PM Kit Peters <popefelix@...> wrote:
Where can I find a mini usb to 4 bare wire cable? 

Bare end mini usb

Kit Peters

Where can I find a mini usb to 4 bare wire cable? 

Hycas AGC


Here is the Hycas document.  I use this for all of my creations. 




…_. _._

Re: nextion 3.5" wrong screen size

Adam Allen

Hey if this is how it has to stay I’m happy with it.  For the last several months I was using the 1.20 cec with the 3.5 nextion and there was some functionality issues, so this is a welcome improvement for me.    

Re: nextion 3.5" wrong screen size


That may be my mess-up.  While resizing some things, a feature or two that I don't use, may have lost itself in error.  I'll revisit the files and resume learning.


Re: Revamped I2C S-Meter for KD8CEC Firmware with Nextion. #arduino #fft #firmware #nextion #smeter



Thank you.  It'll be a few days but I'm looking forward to trying this.


Re: Just placed my order for the full kit today.


Excellent to hear.  


This message sent to you from my mobile device via speech-to-text technology.

Re: Multisim - AGC (JACK-AL version)



I am not prepared to repair your simulation fault - but I can provide a clue on the AGC.  it is similar to the hybrid cascode (hycas) introduced by W7ZOI.  see what info you can find online - the article or related into may be there.  if not email me and I will dig for it. 

also the Jackal developers will gladly answer your questions also. 

if you did your own circuit - I would carefully check the front end matching on the input of the IF AGC amplifier.  if it is similar to the hycas, it requires a trimmer capacitor to peak the response. 

73 Curt wb8yyy

Re: nextion 3.5" wrong screen size

Adam Allen

Okay, I found it.  You have to turn Setup to “On” first, then you can access the CW Key settings. 

Re: nextion 3.5" wrong screen size

Adam Allen

I just changed over to this firmware today and like it. But I noticed there isn’t an option to change the CW keying.  It is in Iambic A and the menu doesn’t have an option to adjust.  Depressing the encoder to get into that menu doesn’t have an option either.

Anyone else notice this? 


Multisim - AGC (JACK-AL version)

Ravi Miranda


Continuing my curiosity on how an AGC works in practise, I tried to
simulate the mentioned AGC circuit using Multisim.

The simulation runs for a few seconds and then comes up with an error message.

The S-Meter output shows the output signal in nV/dbm but it is very
low even if I increase the signal level. What would be the signal
level in uV after 2 stages of amplification, should I be trying to
simulate a complete section before trying to simulate the AGC on its

What I am doing wrong/not reading correctly?

I've also added the first stage of the uBITx as a test, this works
correctly. Both files are in the same folder.

Thank you for your time.

Best 73,
I'm here to add more value to the world than I'm using up.

For sale: uBITX V.3


Good day to all,

I have for sale the uBITX v.3 HF SSB/CW transceiver. 3-30MHZ up to 10 watts output. Bought the kit several years ago and just got to building it last year.  Only issue that I have with it is that once completed, it did not power up. Might be something that i did not do properly. Anyway, I have lost interest in it. The boards and screen are mounted in a 3rd party cabinet, looks great. Photos attached
Asking price: $70.00 + shipping


Janusz  ve2zhp

Re: Just placed my order for the full kit today.


On Sat, Sep 26, 2020 at 07:22 PM, Randy.AB9GO wrote:
My uBitx v6 was posted Friday and it has now left Germany!  That's very fast.  Projected delivery is Thursday.  I think it may beat that estimate unless DHL gets slower once you hit the United States.  
Has anyone needed to pay customs in the United States?

Nope, none of my orders from India incurred additional customs charges.


Re: nextion 3.5" wrong screen size

Evan Hand

Check out the links on this message:


Re: test points

Evan Hand

The Si5351 does generate square waves.  As the frequency goes up, the square wave tends to round off, that or my scope (100MHz) may be filtering the signal at the 70MHz and 45MHz areas of the transceiver.  Regardless, I too have corrupted sine waves on the other two clocks, the high one almost a sine wave.  This could also be related to how long the signal runs are from the Si5351 to the mixers.

Good luck with the new antenna.  That is the most important area for good operation.

Re: test points


Hello Evan,
Thanks for the measures.
It’s exactly the same signal I’m getting.
On the other hand, the other 2 clocks are perfectly sinusoidal.
So everything is normal for me.
I am waiting to receive a reception antenna that I ordered from Jeff. I would then redo reception tests.

Re: test points

Evan Hand


You are correct on Q12 collector voltage error in the documentation.  I do not have access to correct that document as it came from someone else.

Here are the two waveforms on either side of R110:

The probe is compensated, so the ripple is from the Si5351.  Of course, the higher Vpp is the side closest to the Si5351 (Raduino).  This was while connected to a dummy load, so there was no audio on the signal.

Hope this helps

Revamped I2C S-Meter for KD8CEC Firmware with Nextion. #arduino #fft #firmware #nextion #smeter

Dennis C

Here is something I want to share with the community. I have done quite a bit of work on the standalone S-Meter from KD8CEC.  The functionality Dr. Lee has provided in his firmware is fabulous, and this is my contribution to the effort.  I did this using a V4 board, but I think these changes are version independent - just requires use of KD8CEC firmware.

The Summary is below, full details are in the ReadMe on GitHub at  The new version is under i2cmeter2

This started with 2 simple goals in mind, but snowballed into a pretty large revamp and more improvements that I originally intended.  The original intent was:
  • Get the CW decode to function (it was not working for me)
  • Memory was very constrained - reduce memory usage so future new functionality can be added.
Here are some highlights. See the ReadMe on GitHub for the details.
  • CW decode mods - hard to tell degree of improvement, but it now works for me if the signal is not too weak.
  • Significant reduction in memory usage
  • More accurate frequency display on FFT (Requires a Nextion UI tweak)
  • Faster, higher resolution S-Meter (higher resolution Requires a Nextion UI tweak, High resolution is optional)
  • Calibratable S-Meter (and circuit for optional signal boost)
  • Calibratable Power/SWR Meter
  • Fixed several potential stability issues.  I never experienced instability - I corrected things I noticed that might have one day caused an issue.
  • Significant code streamlining and reorganization.
  • Optional faster Serial speed (requires tweak to Nextion and Ubitx firmware)
  • Improved frequency change latency when the FFT is being displayed
  • Optional support for using the Hardware serial output port instead of Software serial.
I also included my customized Nextion firmware (3.2" display)
  • Tweaks to go with the changes above.
  • Added Power and SWR meter screen (graphical)
  • Added Power and SWR (numeric) to main screen when transmitting - SWR flashes yellow/red when too high
  • Streamlined MEM to VFO screen
    • Frequencies are loaded when the screen opens
    • Selecting a frequency immediately returns to main screen
  • I think there may be other tweaks I did some time ago - I don't recall the specifics.

Dennis WC8C

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