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ubitx project

EB7ME
 

Hello everyone.
I’m working on my uBitx project, with my own PCB design.
The “front-end” is also different from original.
The receiver is already working.
If it can help someone, I have uploaded a video to YouTube with the first receptions test.
This is the first version, without Xtal filter for 45MHz.
I’m using an End Fed antenna for 40, 20 and 10 m. It’s only about 4m above the ground and between houses, so it’s performance is not the best

To watch the Video:   https://youtu.be/xc9WvcrC_ws

or search for “amh1147” on YouTube

Regards


EB7ME

Norberto Modanesi
 

Hola Andres:

Qué software has usado en el Raduino?

73 – LU5DNM

 

De: BITX20@groups.io [mailto:BITX20@groups.io] En nombre de Andres Moreno
Enviado el: jueves, 23 de noviembre de 2017 09:18 a.m.
Para: BITX20@groups.io
Asunto: [BITX20] ubitx project

 

Hello everyone.

I’m working on my uBitx project, with my own PCB design.

The “front-end” is also different from original.

The receiver is already working.

If it can help someone, I have uploaded a video to YouTube with the first receptions test.

This is the first version, without Xtal filter for 45MHz.

I’m using an End Fed antenna for 40, 20 and 10 m. It’s only about 4m above the ground and between houses, so it’s performance is not the best

 

To watch the Video:   https://youtu.be/xc9WvcrC_ws

 

or search for “amh1147” on YouTube

 

Regards

 

 

EB7ME

 

EB7ME
 

Hola, Roberto:
      He usado una placa Arduino Mega 2560, una pantalla a Nokia 5110, tres  encoders mecánicos y tres pulsadores.
El programa es un desarrollo propio para usar estos elementos y disponer de un encoder para sintonía, otro para cambio de bandas y selección de Vfo (5 por banda, independientes), y otro para Rit y selección de paso de sintonía. También tiene posibilidad de ajuste de las frecuencias de BFO para USB y LSB, así como de la frecuencia para la segunda FI.
No está lo suficientemente bien comentado como para ponerlo a disposición general, pero si te interesa, por supuesto te lo envío.

Saludos

Andrés 





El El jue, 23 nov 2017 a las 15:41, Norberto Modanesi <norberto.modanesi@...> escribió:

Hola Andres:

Qué software has usado en el Raduino?

73 – LU5DNM

 

De: BITX20@groups.io [mailto:BITX20@groups.io] En nombre de Andres Moreno
Enviado el: jueves, 23 de noviembre de 2017 09:18 a.m.
Para: BITX20@groups.io
Asunto: [BITX20] ubitx project

 

Hello everyone.

I’m working on my uBitx project, with my own PCB design.

The “front-end” is also different from original.

The receiver is already working.

If it can help someone, I have uploaded a video to YouTube with the first receptions test.

This is the first version, without Xtal filter for 45MHz.

I’m using an End Fed antenna for 40, 20 and 10 m. It’s only about 4m above the ground and between houses, so it’s performance is not the best

 

To watch the Video:   https://youtu.be/xc9WvcrC_ws

 

or search for “amh1147” on YouTube

 

Regards

 

 

EB7ME

 

Norberto Modanesi
 

Gracias por tu respuesta. Sí me interesa, si me lo envías, te estaré muy agradecido.-

73

 

De: BITX20@groups.io [mailto:BITX20@groups.io] En nombre de EB7ME
Enviado el: jueves, 23 de noviembre de 2017 04:10 p.m.
Para: BITX20@groups.io
Asunto: Re: [BITX20] ubitx project

 

Hola, Roberto:

      He usado una placa Arduino Mega 2560, una pantalla a Nokia 5110, tres  encoders mecánicos y tres pulsadores.

El programa es un desarrollo propio para usar estos elementos y disponer de un encoder para sintonía, otro para cambio de bandas y selección de Vfo (5 por banda, independientes), y otro para Rit y selección de paso de sintonía. También tiene posibilidad de ajuste de las frecuencias de BFO para USB y LSB, así como de la frecuencia para la segunda FI.

No está lo suficientemente bien comentado como para ponerlo a disposición general, pero si te interesa, por supuesto te lo envío.

 

Saludos

 

Andrés 

 

 

 

 

 

El El jue, 23 nov 2017 a las 15:41, Norberto Modanesi <norberto.modanesi@...> escribió:

Hola Andres:

Qué software has usado en el Raduino?

73 – LU5DNM

 

De: BITX20@groups.io [mailto:BITX20@groups.io] En nombre de Andres Moreno
Enviado el: jueves, 23 de noviembre de 2017 09:18 a.m.
Para: BITX20@groups.io
Asunto: [BITX20] ubitx project

 

Hello everyone.

I’m working on my uBitx project, with my own PCB design.

The “front-end” is also different from original.

The receiver is already working.

If it can help someone, I have uploaded a video to YouTube with the first receptions test.

This is the first version, without Xtal filter for 45MHz.

I’m using an End Fed antenna for 40, 20 and 10 m. It’s only about 4m above the ground and between houses, so it’s performance is not the best

 

To watch the Video:   https://youtu.be/xc9WvcrC_ws

 

or search for “amh1147” on YouTube

 

Regards

 

 

EB7ME

 

VK3HN
 

Hi Roberto and Andrew

I have a part built ubitx as well.  I ran Raduino software on Arduino nano, using all 3 clocks, and found the large number and strength of birdies on all bands made the rx unusable.  I assumed the si5351 was just too dirty when using 3 clocks.  However I moved onto another project and did not spend time debugging my build.  Did you use si5351 and if so, is it clean enough?

73 Paul VK3HN. 

Ashhar Farhan
 

The birdies are a result of the oscillator radiating out from the wires. If there are ground loops or wires connecting the radiuno to the main circuit, you will get these birdies for sure. 
just for this, the raduino has a number of ground lines on both sides of the oscillator outputs. see the pictures of ubitx builds to see how i have soldered the raduino connector directly to the ground plane. with this, all the birdies are virtually gone.

- farhan

On Tue, Nov 28, 2017 at 9:39 AM, VK3HN <prt459@...> wrote:
Hi Roberto and Andrew

I have a part built ubitx as well.  I ran Raduino software on Arduino nano, using all 3 clocks, and found the large number and strength of birdies on all bands made the rx unusable.  I assumed the si5351 was just too dirty when using 3 clocks.  However I moved onto another project and did not spend time debugging my build.  Did you use si5351 and if so, is it clean enough?

73 Paul VK3HN. 


Dimitar Pavlov
 


Hi All,

From my experience with si5351 , I think results will be bether when use crystal BFO with another one 12 MHz crystal, like
other projects from Mr. Farhan, and use A and B channel from Si5351 to drive other - VFO and SECOND_OSCILLATOR.
(I know that Si5351 has 2 channels - A and B, and 3 outputs CLK0,1,2 - 2 outputs share 1 channel (I think this is B channel)).
This is easy to read from documentation. If we found 57 MHz crystal will be better to make second oscillator with crystal to.

(I'm also have soldered but freezed uBitx old schematic experiments :) )
73! Dimitar

On Tuesday, November 28, 2017, 9:14:51 AM GMT+2, Ashhar Farhan <farhanbox@...> wrote:


The birdies are a result of the oscillator radiating out from the wires. If there are ground loops or wires connecting the radiuno to the main circuit, you will get these birdies for sure. 
just for this, the raduino has a number of ground lines on both sides of the oscillator outputs. see the pictures of ubitx builds to see how i have soldered the raduino connector directly to the ground plane. with this, all the birdies are virtually gone.

- farhan

On Tue, Nov 28, 2017 at 9:39 AM, VK3HN <prt459@...> wrote:
Hi Roberto and Andrew

I have a part built ubitx as well.  I ran Raduino software on Arduino nano, using all 3 clocks, and found the large number and strength of birdies on all bands made the rx unusable.  I assumed the si5351 was just too dirty when using 3 clocks.  However I moved onto another project and did not spend time debugging my build.  Did you use si5351 and if so, is it clean enough?

73 Paul VK3HN. 


Henning Weddig
 

think about the fact, that three squarewaves are generated within a tiny chip, for clocking digital circuits crosstalk normally is not a bit issue, but for analog circuits this must be an issue!

This means that to use three SI5351 for individualt frequecies seems to me the best solution. The chips are cheap!!

For best freqeuncy stability only one xtal osc ( TXCO or even OCXO 25 MHz or 27 MHz) should be used, but its three outputs must be "perfectly decoupled" meaning mimimize the crosstalk between the outputs of the buffer stages.

Another thought:

The second osc for the conversion 45 MHz - 12 MHz should not be blaced within the range of the first LO i.e. 45 + 12 = 57 MHz) but 45 - 12 MHz = 33 MHz. This is quite close to the maximum input frequency of the uBITX (30 MHz).  Lowering the second IF to say 5 MHz would ease the situation.

At least: the phase nosie performance of the SI5351 is not at its best and degrades the higher the output frequency is.

Henning Weddig

DK5LV


Am 28.11.2017 um 05:09 schrieb VK3HN:

Hi Roberto and Andrew

I have a part built ubitx as well.  I ran Raduino software on Arduino nano, using all 3 clocks, and found the large number and strength of birdies on all bands made the rx unusable.  I assumed the si5351 was just too dirty when using 3 clocks.  However I moved onto another project and did not spend time debugging my build.  Did you use si5351 and if so, is it clean enough?

73 Paul VK3HN. 

Jean-Matthieu F5RCT
 

Hello all,

As said in datasheet of SiLabs, decoupling and ground plane is very important (see §6)
On raduino the GND via is too far from chip !! ..and it causes a common impedance to ALL outputs !
May be with arranged layout and better GND we can improve spurs...

I did several tests and trails to improve bridies and spurious of the Raduino module :
https://groups.io/g/BITX20/message/33741
- with one activated output : it is clean !
- loading all 3 outputs at 50 ohms instead of one makes more bridies !
- grounding the Xtal casing : no improvement
- having seperate 50 ohms coax is better, but there is still coupling on tracks from the chip to Raduino's terminals (puting the finger on it increase more spurs)
- reducing the driver output current and power improve much more better : at level 1 (4 mA) I have +8.5 dBm, with a 2 dB attenuator pad it is just sufficient for +7dBm mixer
with 0.1 dB added loss compared to +10 dBm drive at level 2 or 3
- I will try at level 0 (2mA) +4.5dB without attenuator to mixer...
- using industrial mixers with -50 to -60dB LO rejection are better than self made mixers : TFM-2, SBL-1, SRA-1 ... the coupling LO to RF or LO to IF is reduced

I aggree with Henning notes and will try to change 2nd osc to 33 MHz (but 33-11.997... = 21.003.. MHz !),or find a 33 Mhz xtal...

For Dimitar, I tried activating PLL B on Farhan's software : no change on spurs ! I found on library that PLL B is not affected on CLK0,1,2  anyway !
Now I'm using Allard's subroutines to configure the Si5351 instead of the library, I spare about 10 ko of ROM in the Nano !!! but no change on bridies  !

I'm rebuilding the Ubitx software from Fahran with corrections, improvements and  Allard's tricks : real dual VFO, A=B, RIT, new Smeter, adding voltmeter, tuning more stable,...
Now I'm facing to CW mode and review the compete function...
I'm not an expert in C++ , I started to learn since september with this project (I have a stong backgrouned in assembler)

 To EB7ME, is your receiver clean ? Did you try with antenna connected to a dummy load ?

73 de F5RCT
Jean-Matthieu

Andrés Moreno
 

Hello Paul:
Well, yes, I used Si5351, since I am following Farhan's instructions as best I can.
Basically, my set corresponds to the idea of Farhan, except in the control, since I am using an Arduino Mega 2560 board and mechanical encoders.
The main difference, apart from the previous one, is that in the design of my PCB I have included the Si5351, so the connections of this IC to the mixers are very short.
In the attached pdf you can see the design.
In my receiver  some birdies appear, but it works acceptably well. In fact, I get clear signals in all the bands (you can see it in the video)

73 Andrés EB7ME

Andrés Moreno
 

The project is on the right track.
Everything is already in a metal box (cookie), it is already possible to transmit, getting about 12W in 40m. and approximately 7 in 20m. For the other bands I do not have antennas.
QSO's in 40m are relatively easy to do, depending on the propagation, but even with my precarious antenna I have been able to perform QSO's with EA8 and HB9, in addition to practically all EA. Keep in mind that I use a mic preamp that has some compression.
The front-end has changed, being governed by an arduino mega2560 pro and a 2.4 "touch screen.
It is possible to adjust the frequencies of BFO, IF, CW Tone and an offset if necessary for the VFO. For the Si5351 the calibration factor and the outputs can be adjusted.
As a disadvantage, this Arduino works at 16MHz and it seems that, together with the screen, it introduces some noise. Working now to eliminate it.
I just uploaded a small video showing all that:      https://www.youtube.com/watch?v=18RdGJ-0sto
or search for "ubitx EB7ME" on YouTube

Thank you very much Farhan for your great idea.

Regards 

EB7ME  Andrés

Mike Woods
 

Andrés

Really good, and I like your screen layout and features.  Are you going to open source your sketch so that others can make use of it?

73 Mike ZL1AXG

On 11/02/18 7:10 AM, Andrés Moreno wrote:
The project is on the right track.
Everything is already in a metal box (cookie), it is already possible to transmit, getting about 12W in 40m. and approximately 7 in 20m. For the other bands I do not have antennas.
QSO's in 40m are relatively easy to do, depending on the propagation, but even with my precarious antenna I have been able to perform QSO's with EA8 and HB9, in addition to practically all EA. Keep in mind that I use a mic preamp that has some compression.
The front-end has changed, being governed by an arduino mega2560 pro and a 2.4 "touch screen.
It is possible to adjust the frequencies of BFO, IF, CW Tone and an offset if necessary for the VFO. For the Si5351 the calibration factor and the outputs can be adjusted.
As a disadvantage, this Arduino works at 16MHz and it seems that, together with the screen, it introduces some noise. Working now to eliminate it.
I just uploaded a small video showing all that:      https://www.youtube.com/watch?v=18RdGJ-0sto
or search for "ubitx EB7ME" on YouTube

Thank you very much Farhan for your great idea.

Regards 

EB7ME  Andrés


--
Mike Woods
mhwoods@...

Andrés Moreno
 

Of course, Mike.
But first I have to "clean it up" and translate comments, because they are in Spanish. I will start doing that and  I think I can offer the open source sketch for those who want it in a few days.
73 Andrés EB7ME