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Re: Very low audio/hiss from uBitx speaker after Nextion 3.5 update #nextion #v6 #ubitx #ubitxv6

_Dave_ AD0B
 

My solution to a slight noise problem was to use a small toroid and wrap the 4 nextion leads through it.

I run a nextion 3.5 on my ubitx without additional regulator. Added in a heat sink to the existing 7805. Have not had a problem in the 2 years that it has been that way. 

Is your radio in a metal case?

Perhaps a high pass filter may be needed for BCB interference. 
--
73
Dave
ADOB
Raduino bracket and Ham_Made_Keys


Re: Pin 8 and Pin 9 on KT1 #ubitx #v3

Rubens Kamimura
 

Gordon,
Would you like to understand the function of each "KTx" relay, which selection each "KT" relay corresponds to? I also want to improve them.
Congratulations on your changes.
73's
Rubens
py2pvb


Re: Pin 8 and Pin 9 on KT1 #ubitx #v3

Rubens Kamimura
 

Gordon,
I would like to understand the function of each "KTx" relay, as I also want to improve them.
Congratulations on your changes.
73's
Rubens
py2pvb


Re: Portable Ops #ubitxv6 #portable

Frank Dinger , EI7KS
 

Aaron , Instead of using AA batteries ( I presume you mean NiMH type) I would consider a few 18650 type Li-Ion cells which can be fitted into clamp holders (max 4 in 1 holder) You obviously would need a voltage equalising board , but all those items are low cost and available from the usual asian on-line suppliers.
The actual battery 18650 cells can also be retrieved from old laptop battery packs . Pretty surprising ,these retrieved cells often have a lot of "juice" left and when fitted into clamp holders can be easily replaced .  
Such a home made battery pack is very compact/ low weight  and has a high Ah capacitiy when compared with NiMH units.

Frank   ,     EI7KS


Re: Ubitx 1 watt SSB

Jay - WS4JM
 

Check the polarity of the mic cartridge. One leg is connected to the case, that should be your ground connection


Re: Yes, My homebrew µBitx now work!!

Evan Hand
 

Gerard,
Sorry, I forgot that the audio amp sections were different.  

I think the pop problem would not be solved with the C38 change.  The way it was fixed was between the v3 and v4, where Q74 was added with the gate being driven by the T/R signal from the Nano.


What is the audio level if you remove Q1 on your schematic?  If it does not impact the audio level, then the AGC is working.  If it increases significantly, then the AGC adjustment is off.

To solve the pop problem I would suggest adding the diode, resistor, and connecting to pin 25 of the Nano (drives K1 through a 4.7k resistor).

As to changing the windings on t16, that would upset the impedances of the mixer and may cause bleed-through of the BFO into the later transmit stages.  I doubt that will increase the signal level.  The BFO is low enough in frequency that the mixer should be OK.  The one mixer that is most in question in my mind is the first, RM1.  That has the highest LO requirement (75MHz at the high end) and would push the Si5351a for drive level.  Again, I still think that you have an audio issue, not an RF one.

I hope this helps
73
Evan
AC9TU


Re: Portable Ops #ubitxv6 #portable

Vic WA4THR
 

Thanks for the comments about my uBitX, Aaron. I used an Excelway case from Banggood as I had picked up a couple when they were on sale for $8 and had used one for my BitX40. I inverted the case so the vent grille can be used as a speaker grille, and the mounting posts are available for top-mounted items (only the speaker in mine) while providing a smoother surface for other circuit boards on the bottom. I also added some rubber feet so the handle could fold up flush when not used as a stand. Having to carry a hamstick for each band, and actually needing an antenna tuner to work when off the hamstick tuned frequency was another reason I switched to the loop. While I have a small auto-tuner that runs off the uBitX power, this way there is one less thing to carry. I have added the SWR bridge and indication mod to the Nextion display so I can confirm proper tuning of the Loop. Here is a larger picture of the rig.



=Vic=


Re: Very low audio/hiss from uBitx speaker after Nextion 3.5 update #nextion #v6 #ubitx #ubitxv6

Vic WA4THR
 

The Nextion display will generate some noise, especially if the brightness is not on full bright. You might want to check that.


Re: Yes, My homebrew µBitx now work!!

Gerard
 

Evan,
Here part of the schematic  for reception and amplifier
The amplifier is a little different from the V6
I changed the C38 to 220µ for POP, but reduce, not eliminate.
For amplification, it lacks strong enough power in the speaker
I wonder if it was a good idea to
multiply by 2 the secondary t16 respecting the phases. Make a kind of Fivecoils respecting the phases. After that remains to add an amp module, or change some values on chain amplifier to get more power?
An idea


Re: Another twist to AGC for the ubitx

Trystan G0KAY
 

Barry,

You have done an exceptionally tidy job of drawing out that schematic.

Trystan


On Sun, Oct 11, 2020 at 10:52 PM, barry halterman wrote:
Evan, yeh, I hit send then realized I had not attached the diagram...
Barry
 

On Sun, Oct 11, 2020, 5:01 PM Evan Hand <elhandjr@...> wrote:
Barry,
Our emails passed each other.  I see the schematic and it is NOT like the one from AmateturRadioKits.  I have another uBITX that does not yet have AGC.  It will take a while until I gather the parts and get the time to make the mod.  I will report back when I get it done.

Thank you for the design.
73
Evan
AC9TU


Re: Very low audio/hiss from uBitx speaker after Nextion 3.5 update #nextion #v6 #ubitx #ubitxv6

Evan Hand
 

vu33gwn,
My first guess at your issue would be you have the wrong hex file loaded, or if you compiled from the source code that the #defaults are not set for the v5 (compatible with the v6).  I would suggest using Xloader and the file UBITXV5_CEC_V1.200_NX.hex from the uBITX_CEC_V1.200.zip archive on GitHub.

The second guess would be that you switched the Nano when you changed the firmware.  If you did, then the calibration data is still in the old Nano, and not transferred to the new one.  You will need to recalibrate the radio if you did swap the Nano.  The best way would be to use the video from Ashhar Farhan and the "yellow box" method to get the calibration settings.
https://www.youtube.com/watch?v=t6LGXhS4_O8

You get to the yellow box by pressing the encoder.  You will then need to set it into calibration mode by rotating the encoder until the set calibration selection comes up.  Press the encoder again.  The yellow box disappears, so you need to press the encoder again to bring it back up.  Now the Calibration and BFO tuning come up as options in the yellow box.  When you have the value set you press the PTT button, wait 10 seconds, and then power cycle the radio.  This ensures the values have been saved to the EEPROM in the Nano.

When doing the calibration be sure to do all three steps:
1 - Set the BFO to the lower edge of the 300 to 3000 Hz window so that you get the lowest tones to zero beat
2 - Adjust the frequency calibration
3 - Go back and adjust the BFO centering the plateau for the best audio level and alternate sideband suppression.

Once you have the rig calibrated I would recommend using the CEC Memory Manager to read the values from the uBITX and save them to a file.  Then you can reload the calibration values at a future date if you need to replace the Nano.  Memory Manager is available here:
https://github.com/phdlee/ubitx/releases/tag/v1.11

Note:  The calibration data is for the Raduino/Mainboard combination.  As long as the two are used together the calibration data is accurate with any Nano used.  You are adjusting the Si5351a clock reference (on the Raduino, NOT the Nano) and the BFO in relationship to the SSB filter on the mainboard. 

73
Evan
AC9TU


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

vu3gwn
 

Would love to have this for a Nextion 3.5


Very low audio/hiss from uBitx speaker after Nextion 3.5 update #nextion #v6 #ubitx #ubitxv6

vu3gwn
 

Hi,

Trying to upgrade my uBitx v6 to a 3.5" Nextion display. 

1. Got the latest build from  https://github.com/phdlee/ubitx/releases/tag/v1.20 and updated the raduino.
2. Found a good build (I hope) for Nextion 3.5" enhanced which doesn't have the problem of small size. 
3. Flashed both raduino and the nextion display.
4. Since the Raduino's 7805 gets heated up too much, so connecting only the data to the Raduino board.
5. A separate power supply for Nextion providing 5v dc.
6. Display works perfectly and I am also able to see a signal line in the graph too...
7. Tx works fine and my external power meter shows a healthy 10w output.

But all I am hearing is a hiss and very low volume commercial radio near 40m.

If I flash back to uBitx v6 stock firmware and reattach the original display, the audio is coming perfect fine.

Any ideas on what the issue is and any resolution ?


Re: Ubitx 1 watt SSB

_Dave_ AD0B
 

try a different mic element. They are less than a dollar. Have had failures with the components. 
--
73
Dave
ADOB
Raduino bracket and Ham_Made_Keys


Re: Another twist to AGC for the ubitx

barry halterman
 

Evan, yeh, I hit send then realized I had not attached the diagram...
Barry


On Sun, Oct 11, 2020, 5:01 PM Evan Hand <elhandjr@...> wrote:
Barry,
Our emails passed each other.  I see the schematic and it is NOT like the one from AmateturRadioKits.  I have another uBITX that does not yet have AGC.  It will take a while until I gather the parts and get the time to make the mod.  I will report back when I get it done.

Thank you for the design.
73
Evan
AC9TU


Changed v4.3 hex if anyone is interested...

 

Hi,

I noticed on the original v4.3 firmware for the 2-line LCD display, that the tuning action was not symetrical when changing directions when tuning.   I looked into the code and it is indeed the case.  So I changed to code a bit to make the action symetrical, and I also change a bit the tuning rate steps and also the sensitivity from changing from one step to the other.

At the same time, I didn't like name for the menu selection "Band Select" since it doesn't select specific bands; so I changed the name to "Fast Tune".  Also, I felt like the speed was a bit too fast, and the knob was too sensitive to movement (when one went to deselect it, often the frequency would change unintentionally).  So I halved the speed and reduced the sensitivity a bit.

I have attatched the code here if anyone wants to try it.  I think the tuning works a lot better like this.

73,  Mark


Re: Another twist to AGC for the ubitx

Evan Hand
 

Barry,
Our emails passed each other.  I see the schematic and it is NOT like the one from AmateturRadioKits.  I have another uBITX that does not yet have AGC.  It will take a while until I gather the parts and get the time to make the mod.  I will report back when I get it done.

Thank you for the design.
73
Evan
AC9TU


Re: Another twist to AGC for the ubitx

Evan Hand
 

Barry,
Did you mean to include a schematic?  I did not see any files in the email.

Your description sounds like one that is available from AmateurRadioKits.  
73
Evan
AC9TU


Re: Another twist to AGC for the ubitx

barry halterman
 

Forgot to add the schematic.


Another twist to AGC for the ubitx

barry halterman
 

Fellow ubitx tinkers. I found this partial circuit in the book, Experimental methods in RF design. It is a double peak detector that gives a smoother AGC response rather then a single diode detector. I have done some work with it and like the response so far. I have attached my drawing of the circuit if anyone wants to test it out. I am using a PIN diode off of the emitter follower Q32. My diode of preference is the 1N5767, but I have used 1N4005, 4007 and MPN3404 diodes with similar response. One thing with this circuit is that is does not load down the audio. With the audio being taken off the high side of the volume control, I built up a small pcb that I can plug right in to the audio connector on the front of the v6 board. Of course since it is detecting audio, there will be that KW down the street that still will blast through, but for the most part it works very well.
Barry
K3bo

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