Hardware dependent DAHDI timing issues were originally repaired by Steve (N4IRS) and Mike (N4IRR) in the DIAL release for X86 and the original Pi release. This patch is necessary as some hardware doesn’t accommodate for VoIP audio streaming properly as a hardware function. Somehow along the way, this fix got lost, broken, or corrupted in later ASL 1.0 Raspberry Pi distributions. Adam KC1KCC found and fixed this in his version which ultimately became ASL 2.0.0. DAHDI timing issues result in a stuttering of the transmitted audio stream, sometimes sounding like a machine gun in the background.
The wide bandwidth rules are an invention of Jeff (WN3A) and are available to widen both the receive and transmit audio path (local) when the usbradio channel driver is used. This is well documented here:
https://wiki.allstarlink.org/wiki/Audio_Filters
Allison (telemetry) ducking is a feature that I envisioned and requested many years ago. Steve Henke W9SH developed and introduced this functionality in XIPAR. Adam KC1KCC finished the porting of this code into this BETA, as well as XIPAR’s “Simple Voter” functionality. Allison Ducking allows you to change the volume of the telemetry (ID’s, node announcements, etc.) under two states - normal (or nominal) and when someone (anywhere) has a PTT depressed. This feature allows you to set the announcement volume level that suits you under these two conditions. I set mine so Allison is reduced in level normally, and even more when someone has the hammer down - allowing local listeners to hear the radio operator over Allison when they are both talking. This is just like what you’d hear from a radio station disc jockey mixing his voice in with program material. The difference is the PTT button is the trigger, not the presence of audio from any user. This ducking action happens with local or remote PTT activity.
Simple Voter is just that - simple. There is no advanced timing corrections, but is a very functional voter allowing for remote receivers to be placed and chosen from comparing quality (RSS) in a large system.
Kevin W3KKC