Audio Technica AT-ONE Installation And Operation Manual page 5

Receiver Functions
Receiver Rear:
1. Antenna BNC Receptacle:
2. Balanced XLR Audio Output
3. Unbalanced 1/4" Jack Output
4. Mic/Line Switch:
5. SQ (Squelch):
6. DC IN:
7. Cable Strain
This provides a connection to the supplied antennas or to
coaxial cable used with an antenna divider, antenna
booster or remote antennas
Use this to adjust the audio output of the wireless
microphone system for mic level (-20dB) or line-level
(0dB)
Turn the squelch to the lowest possible setting (counter
clockwise) to eliminate any interfering signals. In RF
crowded environments (other wireless microphones, LTE,
etc.) it can be required to increase the squelch level
(clock wise) to block out unwanted noise. Please note
that this will reduce the operating distance of the system,
so always seek the lowest possible setting.
DC input connector for the supplied AC adapter