Desensitization problem after a transmission

[Marc Jatteau]

Hello everyone,
I know this question has already been asked, but I haven't seen an answer.
I'm having a desensitization problem after a transmission.
My RP4/RadioBerry/LCD screen/HPSDR
or RP4/RadioBerry/Thétis configuration under Windows.
It's the same in both configurations; I lose about 30dB.
The problem probably comes from RadioBerry or the RP4.

73 F6GKG

[Yado-san]

Hi Marc,

Johan has already released an improved version of the firmware. 

Please confirm its operation.
https://groups.google.com/g/radioberry/c/1O_IMUDEs9g/m/Z-7CnZZTAQAJ
73, 

2025年10月25日土曜日 14:58:24 UTC+9 Marc Jatteau:

[jatteaumarc]

Hello Snail
Thanks for the reply.
Forgive my ignorance, but based on Johan's answer, I don't see how to access the firmware update. Is it for Radioberry or RPI4???
73 by Marc F6GKG

---

From:	Yado-san <shuk...@gmail.com>
To:	Radioberry <radio...@googlegroups.com>
Date:	sam., oct. 25 2025 07:06:19AM UTC
Subject:	Desensitization problem after a transmission

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Sans virus.www.avast.com

[Yado-san]

Please don't worry about it.
It took me over three years to learn the basics of radioberry myself. (Software is difficult)

The simplest solution is to run radioberry_install.sh again.

However, it is smarter to recompile only the modified firmware. 

And the necessary commands are written within the setup script, radioberry_install.sh.

How to:

$ cd /home/pi/tmp

$ git clone  --depth=1 https://github.com/pa3gsb/Radioberry-2.x
$ sudo systemctl stop radioberry

$ cd Radioberry-2.x/SBC/rpi-4/device_driver/firmware/

$ make

$ sudo cp radioberry /usr/local/bin/.

$ sudo radioberry

Hope help..

2025年10月25日土曜日 17:58:28 UTC+9 jatteaumarc:

[jatteaumarc]

Yado-san, Johan,
I reinstalled the firmware and everything works. I no longer have any desensitization issues on either Thetis or piHpsdr.
Thank you both very much.
73 F6GKG

---

From:	Yado-san <shuk...@gmail.com>
To:	Radioberry <radio...@googlegroups.com>

Date:	sam., oct. 25 2025 10:56:03AM UTC

To view this discussion visit https://groups.google.com/d/msgid/radioberry/9f42036e-5926-4d56-b3f9-7297fc9c853an%40googlegroups.com.

[pa3gsb]

now also available for rpi-5.

Enjoy and thanks for testing.

73 Johan

PA3GSB

Op zaterdag 25 oktober 2025 om 14:31:48 UTC+2 schreef jatte...@gmail.com:

[Yado-san]

Hi Johan,  Marc,

Thanks for the rapid confirmation.

I checked the issues with the old firmware using the latest pihpsdr and Thetis, and I also confirmed that the latest firmware has no problems.


But why does the gain drop only on the first MOX(sending/receiving) switch? I couldn't figure out why...

  finally realised after displaying the command and control values.
  ...Actually, I asked the AI-teacher several times. Hi.Hi.

  also fined why the problem did not occur with SparkSDR or the previous pihpsdr.

_ LNA gain is not set correctly before improvement. Updated entry for separate command MOX=0 and 1.

  Improvement:　radioberry.c _ send_control()
    Before: uint32_t command_data = commands[command];
    After:    uint32_t command_data = commands[command & 0xFE];

  radioberry.c _ handleCommand()
    if (commands[command] ! = command_data) {
commands[command] = command_data;.
:
push(command);.
sem_post(&spi_msg);.
    }


Reference:
_ Hermes-Lite2 Protocol1:  https://github.com/softerhardware/Hermes-Lite2/wiki/Protocol
_ Displaying the command and control values

  LNA gain setting commands and control when Thetis (v2.10.3.8) is started.

  (Start-up) LNA gain set to 5A for receive
            to AD9866, (bit6=1, bit[5:0] = -12dB to +48dB)

  MOX: 0, CWX: 0 (command 14)
  commands[0x14]=0x00000000, commands[0x15]=0x00000000
  commands[0x14]=0x00000000, commands[0x15]=0x00000000
  commands[0x14]=0x0017005A, commands[0x15]=0x00000000
  commands[0x14]=0x0017005A, commands[0x15]=0x00000000

 (Omitted) From receiving to transmitting with MOX = 1 --> Receive gain is reduced to 41.

  MOX: 0, CWX: 0 (command 14)
  commands[0x14]=0x0017005A, commands[0x15]=0x00000000
  commands[0x14]=0x0017005A, commands[0x15]=0x00000000
  MOX: 1, CWX: 0 (command 15)
  commands[0x14]=0x0017005A, commands[0x15]=0x00000000
  commands[0x14]=0x0017005A, commands[0x15]=0x00000041
  commands[0x14]=0x0017005A, commands[0x15]=0x00000041

 (Omitted) Return to receive with MOX=0,  -->  the gain remains 41 before improvement.

  MOX: 1, CWX: 0 (command 15)
  commands[0x14]=0x0017005A, commands[0x15]=0x00170041
  commands[0x14]=0x0017005A, commands[0x15]=0x00170041
  MOX: 0, CWX: 0 (command 14)
  commands[0x14]=0x0017005A, commands[0x15]=0x00170041
  commands[0x14]=0x0017005A, commands[0x15]=0x00170041

 (Omitted in the middle) Receive variable (5A to 59) sets the LNA gain to 59.

  MOX: 0, CWX: 0 (command 14)
  commands[0x14]=0x0017005A, commands[0x15]=0x00170041
  commands[0x14]=0x00170059, commands[0x15]=0x00170041
  commands[0x14]=0x00170059, commands[0x15]=0x00170041

  
_ SparkSDR control values.
   Since the values are the same regardless of transmit and receive, there is no issue.
　commands[0x14]=0x0000005B, commands[0x15]=0x0000005B

_ Previous pihpsdr
  The values were close during transmit and receive, so couldn't identify the issue.
  commands[0x14]=0x40100059, commands[0x15]=0x4010005F
//

Yado-san, jg1twp

[Ricardo Suarez]

Solved here.

Compiled new driver version, installed and all OK!

Thanks!

Rick LU9DA 

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[Mario Vano]

Updated to latest Bookworm on my Pi 4 based Transceiver, then did the full Radioberry Install (not piHPSDR) and rebooted.

Works perfectly. Thanks for fixing this! It wasn't stopping anything, but it was just a nuisance. This is so much nicer!

I hate to ask you this Johan, since you're very busy, but is it possible there's an initialization bug like this in the bias read as well? I'm not currently working on anything that uses this, but when I was trying to get a board using your preamp design built, I was having a terrible time with the bias value changing after every reboot. It looked like the driver may have been writing to one of the bias pots on startup (but I can't remember for sure - I've set that board aside for now and am working on some other things - like your new pi 5 image!)

In any case, it's not too important that you look at this any time soon, but I'm curious if you think there could be a bug like that in there. Someday I'd like to get back to investigating why some of the preamp boards are so fragile, and I think it may be related to a bias bug.

thanks again for the desense fix...

Mario AE0GL

[pa3gsb]

Mario,

i updated the rpi-4 with the same change i did for the bias for rpi-5.

Bias is never updated during initialisation.

73 Johan

PA3GSB

Op zondag 26 oktober 2025 om 02:15:40 UTC+2 schreef mpv...@gmail.com:

[pa3gsb]

Yado-san

good analyse !

The protocol is always a static view... the dynamic part, use and interpretation of the protocol is often a suprise as we see with all the different sdr  programs supporting this  protocol.

Enjoy the need of reseting your rx level.

73 Johan

PA3GSB

Op zaterdag 25 oktober 2025 om 19:00:37 UTC+2 schreef Yado-san:

[Mario Vano]

Thanks for clarifying that. I'll get back to my experiments with the preamp boards once I get some time!

Too many projects!

Mario AE0GL

[Mario Vano]

Well put! We've all been there!

M

[Tim ORourke]

So just change to this :

$ cd Radioberry-2.x/SBC/rpi-5/device_driver/firmware/

for RPi 5?

Tim