Lab599 has just announced that firmware v1.10.04 has been published for the Discovery TX-500 and is available for download on their website.
New: Audio modes
The new firmware adds two switchable audio modes: 1W “Normal” mode and 3W “Outdoor” mode. Although I’ve always felt the audio gain on the TX-500 was excellent, this will give even more granular control of volume levels.
New: Antenna SWR Monitor
“This new function will provide you a graph to determine characteristics of the antenna (SWR) in the range of the selected band.”
They shared the image above of the TX-500 display and have already added this along with details in their downloadable user manual.