V4 board, tuning off by 1k, audio low, no luck with audio amp. #ubitx-help #v4 #audiocircuit


bkeahl@...
 

I've taken this project off the shelf, put it back on, and taken it back off a couple times, but want to put it to work on SOTA/POTA but seem to be stopped at the 5 yard line! Its fully assembled, boxed, I've added fusing, internal batteries, the CEC firmware update, a variety of connectors (Kenwood speaker mic, independent headphone & mic jacks, and computer audio interface so I can use a pi and LED display to do digital). 

First, it seems to tune about 100khz off, but the audio sounds right *if I can hear it at all*.  Audio is extremely low, and I know the V4 has that problem. Built a couple LM386 audio amp circuits and didn't seem to help much.

I've tried calibrating it several times, but seem to always end up 100K off! Any ideas on this? 

Audio is so low I can barely pick up signals that come in very strong on my regular rig.  I don't expect Icom performance, but at this level the unit is unusable. Any audio only hacks that people have had luck with?  I do not want the AGC/AMP from QST, as I have already done the RF hack. 

Is it possible the two issues are related?

Thanks in advance,
Brian - WX4BK


Vic WA4THR
 

Is the audio low on all bands or just 20m and above? I also have a V4 and it needs a couple audio mods, one to fix a distortion problem and the other to equalize audio output. Here is a link to the mods made on mine: http://www.ecars7255.com/Ham%20Projects/WA4THR/uBitX%20radio%20mods.pdf

If you have installed the KD8CEC software, using the Memory Manager program makes changes to calibration and such a bit easier as you see and load the desired values directly from another computer. It may be your BFO frequency is pretty far off and that could affect sensitivity and distortion. Perhaps best to start with "typical" values all over and adjust from there. Here's a snapshot of the values on mine, which has great sounding audio, right on frequency, and gets compliments over the air:



Good luck!
=Vic=


Curt
 

Poor sensitivity, i wonder if your agc mod may not be properly installed, bypass it if you can. 

100 kHz off? That I cannot imagine, but of course address with pll correction. Now bfo calibration is much more critical to receiving. 

Curt wb8yyy 


 

Brian,

Have you the right CEC version for your board ? Check!

Raj

I've tried calibrating it several times, but seem to always end up 100K off! Any ideas on this?

Audio is so low I can barely pick up signals that come in very strong on my regular rig. I don't expect Icom performance, but at this level the unit is unusable. Any audio only hacks that people have had luck with? I do not want the AGC/AMP from QST, as I have already done the RF hack.

Is it possible the two issues are related?

Thanks in advance,
Brian - WX4BK \


bkeahl@...
 

Thanks Vic.  Audio seems pretty consistent across bands, and I seem to have gotten tuning closer, but still not happy. I'll see how my values compare with yours, which may give me a clue on what is going on.

B

On Tue, Sep 7, 2021 at 03:31 AM, Vic WA4THR wrote:
Is the audio low on all bands or just 20m and above? I also have a V4 and it needs a couple audio mods, one to fix a distortion problem and the other to equalize audio output. Here is a link to the mods made on mine: http://www.ecars7255.com/Ham%20Projects/WA4THR/uBitX%20radio%20mods.pdf

If you have installed the KD8CEC software, using the Memory Manager program makes changes to calibration and such a bit easier as you see and load the desired values directly from another computer. It may be your BFO frequency is pretty far off and that could affect sensitivity and distortion. Perhaps best to start with "typical" values all over and adjust from there. Here's a snapshot of the values on mine, which has great sounding audio, right on frequency, and gets compliments over the air:



Good luck!
=Vic=


bkeahl@...
 

No, the difficulty existed prior to the mod, and I have bypassed it just to be sure. I've got it tuned much better, but still seems a little off. 
B


On Tue, Sep 7, 2021 at 05:15 AM, Curt wrote:
Poor sensitivity, i wonder if your agc mod may not be properly installed, bypass it if you can. 

100 kHz off? That I cannot imagine, but of course address with pll correction. Now bfo calibration is much more critical to receiving. 

Curt wb8yyy 


bkeahl@...
 

I seem to have things tuned up better, but the audio sound a little odd. I've attached video/audio to see what I'm talking about.  I can move the frequency around but a little low, a little high, and on frequency seems distorted. It also seems like the pitch is better at 100hz high on the tuner, as they appear to be on 14.327 by my IC-718. I've seen this behavior repeat on other bands/frequencies. I've gone through calibration/BFO process as I believe I'm supposed to, several times, but seem to get these same results. Any thoughts on where I'm going wrong?  

B


barry halterman
 

What firmware are you running in the v4?
Barry

On Thu, Sep 9, 2021, 11:07 PM <bkeahl@...> wrote:
No, the difficulty existed prior to the mod, and I have bypassed it just to be sure. I've got it tuned much better, but still seems a little off. 
B

On Tue, Sep 7, 2021 at 05:15 AM, Curt wrote:
Poor sensitivity, i wonder if your agc mod may not be properly installed, bypass it if you can. 

100 kHz off? That I cannot imagine, but of course address with pll correction. Now bfo calibration is much more critical to receiving. 

Curt wb8yyy 


bkeahl@...
 

CEC v1.2. 


Evan Hand
 

There are two versions of the CEC v1.2 software.  One for v4 and earlier and one for v5 and later.  How to get the correct file or to select the correct defines should be in the information files in the archive.  I have always used Xloader and the hex files from either the uBITXV234 for the versions listed in the folder name or the uBITXV5 for the v5 or v6 as long as you change the display to one that is supported with the software,  Note that the stock v6 display is NOT supported.  The prior stock displays are.

Hope this helps clarify.
73
Evan


barry halterman
 

Brian, what happens to the received audio when you shift the IF with the slider?
Does the audio get louder or weaker?
Barry

On Fri, Sep 10, 2021, 7:41 PM Evan Hand <elhandjr@...> wrote:
There are two versions of the CEC v1.2 software.  One for v4 and earlier and one for v5 and later.  How to get the correct file or to select the correct defines should be in the information files in the archive.  I have always used Xloader and the hex files from either the uBITXV234 for the versions listed in the folder name or the uBITXV5 for the v5 or v6 as long as you change the display to one that is supported with the software,  Note that the stock v6 display is NOT supported.  The prior stock displays are.

Hope this helps clarify.
73
Evan


bkeahl@...
 

Evan, I only extracted the V234 folder, and that's what I loaded. 

Thanks, 
B


bkeahl@...
 

IF slider? Not sure what you're asking here.  There is no "slider", just the VFO/Volume knobs. If you're referring to the BFO, then yes, I do get the expected changes in volume/tone while adjusting.

B


Evan Hand
 

B,

One of the features of the CEC software is the ability to “shift” the if frequency. With a Nextion graphics display this is done with an on screen slider.  I will assume you are using the stock character display.  I have not looked, but there may be a function in the menus system that does the equivalent.  All of my uBITX have graphic screens, so no easy way for me to test this. 

Have you tried the BFO tuning page that Ashhar Farman has published.  That is a good tool to adjust the BFO. There are directions on the page.

 https://www.hfsignals.com/index.php/bfo-tuning-aid/

There is also a video on how to calibrate the v6. You can use the same process just that the controls will be different.

https://www.youtube.com/watch?v=t6LGXhS4_O8

You can also use the Memory Manager to save settings so that you can go back if something gets set wrong. 

I am not at my computer right now, but if you need more help let me know and I will send more detail when I get back to my desk  

73
Evan
AC9TU

 


barry halterman
 

Brian, Evan has explained the slider function if you have a nextion display. Using the memory manager you can also do the same thing. There is a selection for the 1st IF (45mhz) calibration. Evan shows his setting to be at 80. You might want to play with your value to see if there might be a change in your volume. The reason I bring this up, I too had low RX level but when I played with the slider on my nextion the signals got louder. I then made a change in the value to get it correct.
I don't recall how much I changed that value from default.
Barry

On Sat, Sep 11, 2021, 7:49 AM Evan Hand <elhandjr@...> wrote:

B,

One of the features of the CEC software is the ability to “shift” the if frequency. With a Nextion graphics display this is done with an on screen slider.  I will assume you are using the stock character display.  I have not looked, but there may be a function in the menus system that does the equivalent.  All of my uBITX have graphic screens, so no easy way for me to test this. 

Have you tried the BFO tuning page that Ashhar Farman has published.  That is a good tool to adjust the BFO. There are directions on the page.

 https://www.hfsignals.com/index.php/bfo-tuning-aid/

There is also a video on how to calibrate the v6. You can use the same process just that the controls will be different.

https://www.youtube.com/watch?v=t6LGXhS4_O8

You can also use the Memory Manager to save settings so that you can go back if something gets set wrong. 

I am not at my computer right now, but if you need more help let me know and I will send more detail when I get back to my desk  

73
Evan
AC9TU