Question:  I have a mix of non-TW user panels and RS-603TW two channel beltpacks at my facility, can I use the non-TW user panels on a TW line and RS-603TW beltpacks on a single channel PL line?

Answer:
1.  Using the non-TW panels on a TW line the following will occur:  Only Clear-Com intercom stations equipped with a TW option should be connected to the output of the TWC-701. If a station or beltpack (with the exception of RS-601) not equipped with the “TW” option is connected to the TW intercom line, the studio portion of channel A will be loaded down, reducing volume level and changing sidetone characteristics on that channel. in summary:i) Do NOT put Clear-Com user panels (MS-70x, RM-70x or KB-70x, HB-70x) units on a TW system(However, if a non-TW equipped station is accidentally connected to the TW line, no damage will be caused to the TWC-701/TWC-704 or any system component).
ii) Only a RS-601 beltpack can be connected to a TW system without loading the system. However it will only work on channel B of the TW system.

2.  Using RS-603TWs on a non TW PL line the following will occur:  If a TW-equipped station or beltpack is connected to a standard Clear-Com intercom line (without a TW circuit), only the Channel B portion of the station/beltpack will operate normally. Channel A will appear to be inactive. Channel B intercom audio and “call” signaling is simply passed through the TWC-701 to the intercom station, and operates in the normal Clear-Com manner.
Note:  Using an RS-603TW in this manner it is advised that the Channel A side be set to "OFF" to minimize any power / termination oscillations