The RM-325 is a two-channel intercom user station for the RTS-TW Intercom System. It is designed for use with a headset, and it can be placed on a desktop, or rackmounted with optional rackmount hardware.
There is a separate talk button with talk-on indicator for each channel. Talk buttons feature dual-action, momentary/latching talk operation: a button may be pressed and held to talk, then released when finished, or the button may be tapped once to turn talk on and then tapped again to turn talk off. Latching operation may be independently deactivated for each channel via an internal DIP switch. The channel 1 and 2 talk buttons may also be independently disabled via internal DIP switches. Additionally, there is a an external talk switch input (for footswitch etc.) for each channel via the Aux connector.
Listen Features and Headsets
There is a separate listen volume control for each channel, and a listen volume control for the program input. The RM- 325 accepts a stereo, dynamic-mic headset or a monaural, carbon-mic headset. Default operation is set for stereo listen, with channel 1 assigned to left headphone, channel 2 to right headphone, and program input to both headphones. Internal jumpers permit all signals to be combined for monaural listening. Internal jumpers also permit the program audio to be assigned left or right when using a stereo headset.
Microphone and Microphone Switch Features
The Dynamic-mic headset connector features a balanced, dynamic mic input, and a mic on/off switch input. A remote mic on/off switch may also be connected via the Aux connector. There is an internal mic-sensing circuit for the carbon-mic headset jack, which activates the mic circuit when the carbon mic is on. An internal jumper can configure the carbon mic input exclusively for use as a mic on/off switch input (monaural headphone output is supported in either case). The microphone audio is available as an unswitched (hot, or always on) unbalanced output at the Aux connector.
Talk-off (Mic Kill) Signaling
The RM-325 can send and receive Talk-off signals. Talk-off send and receive can be independently enabled/disabled via internal DIP switches.
There is a call button and indicator, and the RM-325 can send and receive call signals. There is also an internal setup switch to disable call send.
Balanced program audio may be input via the ¼-inch stereo phone jack (PGM) or via the AUX connector.
Line/Local Power Options
By default, the RM-325 receives operating power from intercom channel 1. Alternatively it may be configured to receive power from channel 2 or from a local, 24 VDC power source connected to the AUX connector.
There is a separate sidetone control for each intercom channel. These adjust the level of the station operator’s own voice in the headphones when talking.