Using the Radioberry Pre-amp

[haywardperson]

THe radioberry documentation on Github mentions that the "development" version must be used if the user is going to use the Radioberry pre-amp. Does your install.sh use the "development" version?

Setup

Use the radioberry development release to make use of this board: https://github.com/pa3gsb/Radioberry-2.x/releases

[paulh002]

Sdrberry uses the development version of the radioberry driver. However the remark is I think also related to the "firmware". Sdrberry does not use the firmware part of radioberry but uses SoapySDR. I don't use the pre-amp of the radioberry project. Sdrberry can send I2C commands or the SoapyRadioberry driver should support the pre-amp but I don't think that is the case.

[haywardperson]

It states that the pre-amp can be used stand-alone so it will probably but maybe reduced control.

[paulh002]

I have checked the pre-amp board. It uses I2C te regulate the bias of the mosfets and measure temperature and some other items.
There are some other pins on the connect for rx/tx I think. I have to research how this works. Maybe I have to make a specific page in sdrberry for the preamp.

[haywardperson]

Very nice. The pre-amp board is good for beginners because it takes care of the output filters and combining the RX/TX. Allowing a complete QRP transceiver build.

[paulh002]

Hi Mike,
You can update the SoapyRadioberry driver.

cd SoapyRadioberry
git pull
git checkout build
cd build
cmake ..
make
sudo make install

The in the SDR page you can scroll to the settings page and switch on or off the pre-amp.
I still have one issue that the setting is only send to the radioberry when the drive level is changed or at startup.
If you click on the value, the value will toggle between operate and standby.
This I have to change in sdrberry. But for now you can check if the pre-amp board does switch on.

[haywardperson]

I had to get and install the 8.4v power buck converter for the pre-amp board.
A couple of questions.

1. Is this applicable to the RPI4 build or the RPI5 build or both?
2. The pre-amp board has only one relay, which I assume is for TX/RX switching. Therefore there must not be bandpass filters to clean up the output for acceptable TX quality?

[paulh002]

This works both for pi4 and p5. No difference. It sill needs a bit more work .
Right now this only supports the aursinc pre-amp board, the official pre-amp board of Johan is more complicated.
There the pi also manages the bias current and measures the temperature.
What is now also clear for me is that the firmware used by other sdr programs does not support the aursinc board.
But I don't think there are so many people using that board. Johan told me he did not like that design. There is an alternative board with two opamps a small driver board which is also interesting. Maybe I will try that also.

[haywardperson]

Interesting. Where did you see the alternative board? Is it actually available or the original design? The only one I could find was the Aursinc.

[paulh002]

You have to build it your self

[haywardperson]

OK I see.

[paulh002]

I checked on jlcpcb to get 10 pcb's is only 22 euro inclusive transport and taxes. Maybe I build a number of them. But I also like to design and build it myself. I like the challenge.

[haywardperson]

This project is a challenge for me just buying pre-made boards ! :)