Question:  I recently purchased a ClearCom HME DX200 wireless intercom system to replace a older Telex TR-300 wireless intercom system. I would like to interface my older Telex US-2000 User Station Audiocom Intercomstation from the Telex TR-300 system to the ClearCom HME DX200 system. I would like to use the intercomlink as suggested in the DX200 manual page 20 for 2-wire Intercom. Will this work and will this not damagethe equipment to make this connection ?

Answer:  Current versions of the AudioCom Main Stations and Power Supplies have a BAL/UNBAL Selector Switch: This selector switch allows the user to configure the unit for use in either an Audiocom (BALANCED) or Clear-Com (UNBALANCED) system. Compatibility includes channel connector pinouts, channel power requirements, and call signaling requirements.  The balanced / unbalanced switch is usually located by the 2-wire intercom connectors. 
NOTE:  Verify that the AudioCom 2-wire switch is set to unbalanced before connecting to a Clear-Com or HME wireless product so as not to inject +24V onto pin 3 of the 2-wire IC connector. 

AudioCom Specification for IC channel connector:
Balanced Mode (set to BAL position)
Line Terminating Impedance: 300 ohms ±10%
Connector Pinout
Pin 1 Common (audio and DC return)
Pin 2 Full-duplex, balanced intercom audio and +24 VDC output
Pin 3 Full-duplex, balanced intercom audio and +24 VDC output
Unbalanced Mode (set to UNBAL position)
Line Terminating Impedance: 200 ohms ±10%
Connector Pin-out:
Pin 1 Common (audio and DC return)
Pin 2 +30VDC ±1VDC
Pin 3 Full-duplex, unbalanced intercom audio high