The short answer is: Bit errors affect voice just like they affect data. There's no such thing as a "voice only" or a "data only" stream.
Every stream is complete with voice and data components. "Silence" is still a voice stream that must be properly decoded, and if it got damaged on the way to the repeater or down from the repeater, you hear strange noises instead. It happens often. Have seen what you're describing before during all of the following: - Station is weak into repeater (TX). - Station is mobile and experiencing flutter/fading even though otherwise is in a location that it would otherwise be "full signal" copy at the repeater site. - Repeater is being heard weakly by receiving station (RX), because of shielding or distance. - Local interference on received signal by analog noise, mixing, or desense. - Interference or desense at repeater site. - HT battery dies in the middle of a transmission (audio always goes to "garble" in this case, the decoder is not looking or locked to signal strength in any way, so it keeps "trying" for a period of time). - Doubling. Happens quite often with numberous timer-based data transmission stations. Additionally, there's no good tool (yet) for round-trip bit-error rate testing through the repeaters. Many people are fooled into thinking that if they can talk through the repeater, they're in the equivalent of "full quieting" coverage on analog -- then they find that low-speed data won't pass without errors at all from that radio setup, antenna, power level, and location. Personally with the popularity of dPlus links, thinking it's probably not a great idea to have a bunch of unattended beacons going through the links that can come and go at any time, so I tend to recommend dropping timer-based location data use altogether. I have my rigs set up to do only PTT-based position reports unless there's a special need to know where all those stations are located for an event or something. The radios do that very well and continuous position reporting for anything other than an event or a special mapping of coverage or something, seems like overkill. But your experience with "garbled audio" sounds coming regularly from the speakers of radios that are monitoring this "supposedly all data only" traffic, is normal... if conditions aren't 100% perfect and no doubling ever happens, between the repeater and every node in the network. Nate WY0X
