It looks like Plex is very specific in the Models of tuners that it supports. The AverMedia USB stick I have is the same, but missing the Q in the model number.
Interestingly enough, if I go to the Plex Tuner Service.log, it looks like it sees my tuner, so hopefully it can be supported in the future so I don’t have to buy any additional hardware.
Jun 01, 2017 18:25:35.337 [11240] INFO - * DeviceGetListEx_impl: Filter [AVerMedia USB Digital Tuner]
Jun 01, 2017 18:25:35.337 [11240] INFO - * DeviceGetListEx_impl: device instance path usb#vid_07ca&pid_a868#405081400790#
Jun 01, 2017 18:25:35.337 [11240] INFO - * DeviceGetListEx_impl: pDL->Count:1
Jun 01, 2017 18:25:35.337 [3084] INFO - * DeviceGetListEx_impl: Filter [AVerMedia USB Digital Tuner]
Jun 01, 2017 18:25:35.337 [3084] INFO - * DeviceGetListEx_impl: device instance path usb#vid_07ca&pid_a868#405081400790#
Jun 01, 2017 18:25:35.337 [3084] INFO - * DeviceGetListEx_impl: pDL->Count:1
Jun 01, 2017 18:25:35.352 [3084] DEBUG - * BDA: get_tuner_type_from_filter. Unknown guid type {71985F4C-1CA1-11D3-9CC8-00C04F7971E0}
Jun 01, 2017 18:25:35.352 [3084] DEBUG - * BDA: get_tuner_type_from_filter: ATSC
Jun 01, 2017 18:25:35.352 [3084] INFO - * BDA get_tuner_type. Detected type(s) 8 for device @device:pnp:\\?\usb#vid_07ca&pid_a868#405081400790#{71985f48-1ca1-11d3-9cc8-00c04f7971e0}\{7cf9956a-df4a-441f-8f8a-a1d7b66ab59f}
Jun 01, 2017 18:25:35.368 [13348] INFO - * dvb_device_factory_t::get_device_list. Id dvb#bda#0#@device:pnp:\\?\usb#vid_07ca&pid_a868#405081400790#{71985f48-1ca1-11d3-9cc8-00c04f7971e0}\{7cf9956a-df4a-441f-8f8a-a1d7b66ab59f}, Name AVerMedia USB Digital Tuner, Standards 8
Jun 01, 2017 18:25:35.368 [13348] DEBUG - * file_tuner::get_stream_file. File C:\Program Files (x86)\Plex\Plex Media Server\Resources\Tuner\Private\devices\dvb\file\drv_file.ini does not exist
Jun 01, 2017 18:25:35.368 [13348] INFO - * device_manager_t::get_device_list. Device AVerMedia USB Digital Tuner, id dvb#bda#0#@device:pnp:\\?\usb#vid_07ca&pid_a868#405081400790#{71985f48-1ca1-11d3-9cc8-00c04f7971e0}\{7cf9956a-df4a-441f-8f8a-a1d7b66ab59f}, tuners 1, state 0, standards 8
