TECPRO COMMUNICATION SYSTEM - Talkback loudspeaker stations
Series 2 Tecpro LS300 Loudspeaker Stations provide local monitoring of intercom circuits without the need to wear headphones. The built-in microphone makes them suitable for hands-free operation, allowing full-duplex simultaneous talk and listen conversations to take place. If required, a headset may be plugged in, disabling the internal microphone and speaker. LS300 Loudspeaker Stations offer single circuit operation as standard. Dual circuit versions are available on some models.
- Hands-free or headset operation
- Loudspeakers selected for clear voice reproduction
- Built-in flush-mounted electret microphone
- Microphone On/Off button offers push-to-talk or latching characteristics
- Acoustic feedback cancellation preset
- Side-tone preset for headset
- XLR 4-pin input socket for gooseneck microphone or headset
- Single and dual-circuit versions available on some models
- DC and 20kHz 'Call Alert' signaling send and receive
- 24kHz 'Remote Mic Kill' send and receive
- 28kHz 'Override' signal recognition for preset volume restoration
All Tecpro LS300 Loudspeaker Stations have carefully selected loudspeakers, for clear voice reproduction and a high quality, flush mounted electret microphone. The microphone, loudspeaker and associated controls are all mounted on a machined plate.
LS300 Stations derive power either directly from the 24V DC Tecpro line or, in some cases, from an optional external 24V PSU with a 2.1mm DC connector. Suitable power supplies in the Canford range are 23-984 and 23-925. The external DC supply powers the loudspeaker amplifier directly, thereby considerably reducing the load on the 24V Tecpro line. This helps to avoid the excessive current draw on the system power supply that can result when several loudspeaking stations are connected to it. A green LED indicates power is present.
The loudspeaker lies behind a protective grill and audio output is controlled by a rotary 'Speaker Level' control. The microphone is mounted some distance away from the speaker. The microphone On/Off button offers push-to-talk and latching characteristics depending on the length of time the button is depressed. LS300 stations can generate and respond to 24kHz 'Remote Mic Kill' tone. If tone is detected and the microphone is active, it will be switched off automatically.
Feedback cancellation circuitry helps avoid acoustic 'howl-round' when speaker and microphone are operating simultaneously. This is adjusted via the 'Cancel' preset. To further reduce feedback, a gooseneck microphone may be plugged in, disabling the internal microphone; the operator can speak in closer proximity to the mic capsule, thereby reducing the likelihood of feedback. Plugging in a headset disables both the internal microphone and loudspeaker.
Pressing the 'Call' button causes 'Call Alert' lights on other Tecpro user stations to flash (first generation Tecpro illuminates without flashing) to attract the operator's attention. The 'Speaker Mute' button silences the loudspeaker output. To prevent important announcements going unheard when muted, LS300 stations can be triggered to restore audio levels to a pre-determined volume when a 28kHz 'Override' signal is generated by a master station elsewhere in the system. The 'Override' audio level is adjusted via a preset and can be set anywhere between zero and full volume.
Note: Care should be taken when using LS300 Loudspeaker Stations in hands-free duplex mode. Although excellent acoustic feedback cancellation can be achieved at each station, system feedback can occur if several hands-free units are operated simultaneously. Using the microphone in push-to-talk mode will help reduce feedback. Alternatively, using a headset will eradicate the problem.
||24 to 30V DC
||Less than 175mA peak
|External DC input:
||24 to 30V DC (some versions only)
||Less than 100mA peak with external PSU (some versions only)
||30 ohms to 4k ohms
||200 to 600 ohm dynamic microphones
LS351 - Single circuit, desktop
This has an 80mm loudspeaker and an electret microphone. Construction is based around a rigid aluminium extrusion with ABS side panels. The microphone, loudspeaker and associated controls are mounted on a machined top plate.
The LS351 derives power either directly from the 24V DC Tecpro line, or from an optional external 24V PSU. A green LED indicates power is present. Connection to the intercom system is via a pair of 3-pin XLR connectors which allow the LS351 to be 'daisy chained' with other user stations. Dimensions: 245 x 120 x 90 (l x w x h) mm. Weight: 1150g.
LS352 - Dual circuit, desktop
This is similar to the LS351 but, in addition, can be connected across two intercom circuits. The LS352 can switch between monitoring circuit A or circuit B.
The rear mounted intercom connections comprise two pairs of 3-pin and one pair of 5-pin XLR connectors for flexible 'daisy chaining' with other user stations. Dimensions: 245 x 120 x 90 (l x w x h) mm. Weight: 1150g.
LS361 - Single circuit, wall or surface mounting
Similar to the LS351, this has the extruded aluminium chassis profile modified to make it more suitable for surface mounting the unit on a wall. Screw slots are provided in the rear for convenience. It has a 70mm x 40mm loudspeaker, chosen for its compact dimensions and clear speech reproduction.
Cable entry is through a cut-out on the rear and termination is via an internal junction block. The LS361 derives its power directly from the 24V DC Tecpro line. A green LED indicates power is present. A template is provided to aid fitting. Dimensions: 243 x 110 x 74 (l x w x h) mm. Weight: 1kg.
LS371 - Single circuit, flush mounting
This has a 70mm x 40mm loudspeaker and a flush mounted electret microphone. All components are mounted on a single machined aluminium plate designed to fit a standard UK domestic flush back-box of the type typically used for cooker-switch units (27-379 Tecpro LS379FB flush-mounting back box for LS371). Suitable M5 screws are supplied for attaching the aluminium front plate. Spares are available (14-355).
Cable entry is through the standard knock-out on the back-box rear or side face and termination is via an internal junction-block. The LS371 derives its power directly from the 24V DC Tecpro line. A green LED indicates power is present. Installers should note that the back-box must be turned through 90 degrees from its more usual orientation. A template is provided to aid fitting. Dimensions: 180 x 170 x 57 (l x w x h) mm. Weight: 950g.
LS372 - Dual circuit, flush mounting
This has similar specifications to its sibling LS371, but can be connected across two intercom circuits. The LS372 can switch between monitoring circuit A or circuit B.
LS381 - Single circuit, 1U rack mounting
The LS381 is housed in a 1U case suitable for mounting in a 19 inch rack. It has a 70mm x 40mm loudspeaker, and the same flush-mounting microphone used throughout the range.
It derives power directly from the 24V DC Tecpro line or from an optional, external 24V power supply. A green LED indicates power is present. Connection to the intercom system is via a pair of 3-pin XLR connectors which allow the LS381 to be 'daisy' chained with other user stations. Dimensions: 483 x 44 x 66 (w x h x d), 1U rack mounting, 66mmm deep. Weight: 900g.
LS382 - Dual circuit, 1U rack mounting
This has similar specifications to its sibling LS381, but can be connected across two intercom circuits. The LS382 can switch between monitoring circuit A or circuit B.
The rear-mounted intercom connections comprise two pairs of 3-pin and one pair of 5-pin XLR connectors for flexible 'daisy chaining' with other user stations. Dimensions: 483 x 44 x 66 (w x h x d), 1U rack mounting, 66mmm deep. Weight: 900g.