An active antenna on the roof received nothing until the modem's
antenna supply was switched on (AT+CVAUXV=3050, AT+CVAUXS=1); then +5.5
dB over the passive one. The settings reset on every modem restart and
AT&W doesn't keep them, so interface 03 is reserved as /dev/sim7600-at
(ModemManager ignores it) and a udev-started oneshot re-applies them.
gpsd now re-attaches via gpsdctl after re-enumeration. Verified with a
live modem reset: antenna, LTE and the GNSS fix all recovered unattended.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
mikkeli
68fd0715b8