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N7DDC
Neuling
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I'm a llama!
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Re:DDC Module2
« Reply #16 on: 21. September 2020, 05:57:06 »
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Hello, people.
I am here and I am ready to answer all the your questions.
I am doing the Sparrow 4 N7DDC Edition and this is first of all my own vision how it should have been a power delivery system of modern HAM transceiver with battaries power.
I have changed pinout for CPU because I will need to change the firmware in any way.
The RF board will have everithing needed to use 4 LiFePo elements, balanse and charger and also MCU-companion, wich will to control of power and to send for DSP-MCU all the meassured parameters from buid-in ADC. So board to board connector has mainly I2C bus to connect them each other.
I don't know exactly, who knows, probably Artur's version would be more interested for other people, I just realise myself in this project and obviously doing what I want to have personally.
I am ready to change the firmware of DDC Module 2 if anyone wants to use it in his own projects.
At this time I have assembled the CPU board and working on firmware.
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N7DDC
Neuling
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Re:DDC Module2
« Reply #17 on: 21. September 2020, 05:57:39 »
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other side
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SP9BSL
positron
alter Hase
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Re:DDC Module2
« Reply #18 on: 21. September 2020, 07:32:02 »
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Hello David,
welcome to our forum, glad to see you here. Can you present the list of pinout changes for STM?
You mention on cqham.ru you need to change the UHSDR code to zero IF, can you explain why do you need this?
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73 Slawek
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N7DDC
Neuling
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I'm a llama!
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Re:DDC Module2
« Reply #19 on: 21. September 2020, 15:37:09 »
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Hi.
The header with the pinout you can find here
I need to see the filter on the center of panorama because I can do this using DDC.
Output IQ signals dont have a flicker noise on zero freq unlike signals from audio codec.
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N7DDC
Neuling
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Re:DDC Module2
« Reply #21 on: 21. September 2020, 17:11:00 »
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Hello, Andreas.
All the known SDR progs on PC work in Zero-If and able to work even with variable IF, other words they are able to slide a filter by panorama including zero freq too.
I have noticed one time using QUISK when the 1000kHz domestic AM station is on the center of panorama and the filter tuned on 1000kHz too, the quality of sound is getting very bad. But it is enough to tune the filter even on 1 Herz, the quality is returning back.
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N7DDC
Neuling
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I'm a llama!
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Re:DDC Module2
« Reply #23 on: 21. September 2020, 17:36:39 »
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Is this possible to use IF = 1 Hz or ZeroIF can not to be inside the filter ?
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N7DDC
Neuling
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Re:DDC Module2
« Reply #25 on: 21. September 2020, 21:46:58 »
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HI, Andreas
I think you are not right.
I remember that time 20 years ago when PowerSDR worked with 12kHz IF, but now all known progs can work on zero freq.
The most important advantage is not only symmetrical view, it is the possibility to tune the filter when the panorama and waterfall are motionless.
I will ask somebody who has a lot experience with this and come back soon.
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SP9BSL
positron
alter Hase
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Re:DDC Module2
« Reply #26 on: 21. September 2020, 21:57:44 »
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The most important advantage is not only symmetrical view, it is the possibility to tune the filter when the panorama and waterfall are motionless.
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Hi David,
this feature is already implemented in the code from very beginning. So far we're not using it because of small display and high overhead for F4 core.
I will ask somebody who has a lot experience with this and come back soon.
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Please do it, there is problem with FM in UHSDR at zero IF, I know because I also have working DDC solution with UHSDR (see SParkle threads).
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73 Slawek
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N7DDC
Neuling
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I'm a llama!
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Re:DDC Module2
« Reply #27 on: 22. September 2020, 05:13:44 »
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I have asked George RX9CIM, autor of SDR Tulipan, Visair and Malachit. He confirmed that all the modulation including FM work perfect with zero IF and variable IF.
With sound codec IQ this is impossible.
Tulipan is using STM32F407ZGT6, we have H743 . Should to work !
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N7DDC
Neuling
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I'm a llama!
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Re:DDC Module2
« Reply #29 on: 22. September 2020, 05:39:38 »
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Hi, Andreas
Thank you
I think you have to try the current DSP code with IQ from DDC. Just remove amplitude and phase balansing, DC removing and try.
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Author
UHSDR_UI_ovi40_config.zip
