I always noticed that I had to plug in the USB cable for the remote radio with
the radio switched off, otherwise the Kenwood TS480 would switch into transmit
mode and stay there until I powered the radio off.
Annoying, and I thought it was something in the serial initialization.
Recently I was thinking about this and remembered something about query
sequences on serial devices triggering weird behaviour in other devices.
From what I read about the Kenwood serial protocol the chance of a few stray
characters changing something in the radio is quite possible.
So I considered what Linux software could do a query as soon as a serial
port is added to the system. Well, modemmanager was the ideal candidate for
this:
Package: modemmanager
[..]
Description-en: D-Bus service for managing modems
ModemManager is a DBus-activated daemon which controls mobile broadband
(2G/3G/4G) devices and connections. Whether built-in devices, USB dongles,
Bluetooth-paired telephones or professional RS232/USB devices with external
power supplies, ModemManager is able to prepare and configure the modems and
setup connections with them.
And indeed, simply removing modemmanager made the problem go away. I can
now plug in the USB cable when the radio is on and nothing happens.
