Re: whoosh sound at ends of DMR transmissions
Posted: Sun Apr 25, 2021 2:37 am
Thanks for the detailed explanation Colin, makes perfect sense. After Daniel's suggestion to turn on the CC filter the bulk of the noise disappeared.
G4EML wrote: ↑Sat Apr 24, 2021 9:21 amThe HR-C6000 DMR chip and the firmware normally check the CC to ensure that the received signal is valid. This check is built into the hardware. I managed to find a way of disabling it to allow the CC filtering to be turned off. This is using the chip in a way that was not intended by its manufacturers. Unfortunately this can result in the bursts of noise you are hearing when the signal starts and stops.
In commercial use a DMR radio would never need this feature. However it is a useful tool for amateur radio use.
As Daniel says, this feature is not intended to be used for normal reception. It should only be used for a short time to detect the correct CC for a new signal and then that CC can be entered in the channel details menu.
Colin.