October 2016 Blog Posts (3)

The ability of the A-law PCMA G.711 audio codec to transmit extreme qrq cw audio tones over the internet, is tested using the SIP VOIP CLIENT Ekiga. https://ekiga.im/

FLdigi sends a text at 120 wpm from TOM's famous qrq cw article:

https://sites.google.com/site/tomw4bqf/copyingcwover70wpm

to the input of Ekiga, and Ekiga is connected to an ECHO REFLECTOR so you can hear your…

Testing the ability of iLBC (internet Low Bitrate Codec) to transmit and receive morse code audio tones over the internet with low bandwidth used and good packet loss concealment. By itself, this codec does not make for pleasant copy, however, if the received tone is regenerated, the iLBC CODEC seems to provide a highly dependable internet audio stream of full duplex morse code audio notes...for a QSO between 2 or more cw ops over the internet with low latency - and good qsk -…

Using 2 seperate Jitsi voip clients/computers, that were connected to each other over the internet, this video demonstrates the audio quality of the morse code audio tones as they are transmitted from one SIP CLIENT to the other SIP CLIENT over the Session Initiation Protocol / VOIP / internet pathways. 



Codecs tested for morse code audio quality are:

1. iLBC / 8000

2. Silk / 8000

3. G722 /…