Smokedparts
New member
I have built an SDR amateur radio transceiver based on the work of a ham down in New Zealand. I have not included the code as it belongs to the chap in New Zealand
The initial build was with a Teensy 3.6 and the radio produces an awful whine noise. Switch to a Teensy 3.5 and most of the whine noise disappears. The Arduino sketch is the same for both and the only hardware change is the Teensy. There was a concerted effort to address grounding and avoiding ground loops. To further assure nothing was slipping through the common power supply I installed an active power supply decoupler in the leads to the Teensy/Codec Board
Is there a difference in the structure that prevents the use of the 3.6. I have included a short video link so you can hear the whine.
The sketch was loaded using a Windows 7 machine and the Arduino IDE was 1.8.3. The hardware used was the Teensy, your Codec board, the Adafruit Si5351 PLL Clock generator and a 128X64 Black and White OLED (both using the I2C).
The front end hardware was built by me and was tested using Power SDR installed on a Windows XP machine and an M Audio Delta 44 Sound card. There is no evidence of any whine being generated by the front end board. Again most of the whine is gone with the Teensy 3.5 installed.
OLED's can be noisy and I removed the OLED display and there was no change in the Whine sound.
Any suggestions would be most appreciated.
Smokedparts
The initial build was with a Teensy 3.6 and the radio produces an awful whine noise. Switch to a Teensy 3.5 and most of the whine noise disappears. The Arduino sketch is the same for both and the only hardware change is the Teensy. There was a concerted effort to address grounding and avoiding ground loops. To further assure nothing was slipping through the common power supply I installed an active power supply decoupler in the leads to the Teensy/Codec Board
Is there a difference in the structure that prevents the use of the 3.6. I have included a short video link so you can hear the whine.
The sketch was loaded using a Windows 7 machine and the Arduino IDE was 1.8.3. The hardware used was the Teensy, your Codec board, the Adafruit Si5351 PLL Clock generator and a 128X64 Black and White OLED (both using the I2C).
The front end hardware was built by me and was tested using Power SDR installed on a Windows XP machine and an M Audio Delta 44 Sound card. There is no evidence of any whine being generated by the front end board. Again most of the whine is gone with the Teensy 3.5 installed.
OLED's can be noisy and I removed the OLED display and there was no change in the Whine sound.
Any suggestions would be most appreciated.
Smokedparts