I recently received a Telegram message from Curtis ZS6CMO informing me that my audio on Echolink and AllStar was scratchy and not my normal "pleasant" audio that he is used to. Well I get very agitated with somebody telling me my audio is bad. Do you also get upset? No, just joking. I appreciate the message from Curtis immensely. If you are not told that your transmit audio is poor or bad then how will you know it. Listening to bad audio quickly make me QSY to another station or frequency. In the olden days your were quickly told that your audio is bad and not acceptable. Do something about it!! I am old school and believe that your audio must at all times be acceptable and pleasant to listen to. Unfortunately I cannot change my voice the good Father gave me but I can do something about bad audio. I decided to investigate and explore why the audio was scratchy as I did not alter any settings of the network or radio.
Now where do one start? Here is a few pointers to look at:
- Power Supply functionality. Does you power supply provide the correct voltage and amps.
- Power Supply interference. Check EMI and EMC. (EMC = “ability of equipment or a system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment”. This phrase can be simplified to ‘tolerate outside disturbances and do not disturb the outside world’. EMI = “degradation in the performance of equipment or transmission channel or a system caused by an electromagnetic disturbance”. This phrase defining EMI can be simplified to ‘degradation in performance due to outside disturbances’.
- Noise over the Ethernet coming from switches, hubs, routers, raspberry pi's etc.
- Cooling Fans. Noise generated by cooling fans or their circuitry.
- Internet noise aka WiFi Interference.
- Bad audio from Echolink or AllStar servers
- Microphone issues like bad connection, to close to monitor speakers, bad microphone, incompatibility with PC Soundcard etc.
- Bad Internet connection
- RAM of Raspberry Pi getting full
- Failure to reboot computers and router to reset connections
- Interference from outside my QTH
- Interference from household equipment in the home
- Pre-failure of equipment or dry joints
Now this is quite a comprehensive list but before you say I will not use Echolink or AllStar as there could be more issues that normal RF Radios, I want to assure you that this is not the case. I took a shortcut because I know that if the system has been up and running for some time it needs to be rebooted. This include every item connected to the network or a radio. This will sometimes solve a few hick-ups that might be present. This morning a did a complete shutdown of the network and then restarted everything. After starting up the network the audio issue was solved and the "pleasant" audio was back again. But not for long. After a while it was back. This time around the audio had a buzzing sound and there was no RX. I did some fault finding and found that the USB Soundcard was the culprit. I replaced the unit and low and behold the "pleasant" audio was back. I will later look at the faulty soundcard. At this stage a suspect a dry joint could be the problem.
So I do not have the perfect audio in Echolink or Allstar but I try to provide good audio as far as possible. I think you will agree that many of the above mentioned pointers could occur and cause problems and therefore I listed them here. Hopefully this can help others that do experience problems in this regard.
Just goes to show my audio on Echolink can also be bad and unacceptable.
