TELEX US-2000 (01) PDF Document

The TELEX US-2000 receives power externally in one of two ways:

• Via the 12-15 VDC power input jack.

• Via CHN 1 or CHN 2, the intercom channel connectors.

The TELEX US-2000 has the following initial factory settings:

• Channel Termination: Set for balanced operation, compatible with other Audiocom® equipment. For connection to Clear-Com equipment, settings must be changed as described in the Clear-Com Setup section.

• Speaker Output: Set to allow all channels to be heard through a single powered speaker. To have each channel go to a separate speaker, internal jumpers must be changed.

• Headset Microphone Termination: Set for unbalanced operation. This can be changed via internal jumper J16. If the termination requirement is unknown, the recommended setting is unbalanced.

To reset the TELEX US-2000 microprocessor to its power-up state, simultaneously press the All Talk key and the channel 1 Listen key.

To use the test signal function on your TELEX US-2000, follow these steps:

1. Simultaneously press the All Talk and PA keys. This will cause the microprocessor to generate a 1 kHz test signal.

2. Press any Call key to send the test signal down that channel.

3. Press the same Call key to stop the test signal on that channel.

4. Press any other key on the unit (except a Call key) to exit the test signal function.

Volume Control:

Use the main Volume control knob to adjust the headset listen level.

Sidetone Control:

The sidetone control adjusts the level of your own voice heard in the earphones when using a headset.

1. Tap the Headset key once to turn on the headset microphone.

2. While talking into the microphone, use a small flat-blade screwdriver to turn the Sidetone control to increase or decrease your voice level in the headset.

The TELEX US-2000 has separate VOX level adjustments for the headset and panel microphones. This adjusts the voice level required to activate the microphone when VOX mode is on.

To adjust the headset VOX level:

1. Place the Headset microphone key in VOX mode by tapping it twice (the key will glow orange).

2. While talking into the headset microphone in a normal voice, use a small flat-blade screwdriver to adjust the headset VOX control to the desired voice activation level.

3. The Headset microphone key will turn from orange to green as the microphone turns on, indicating successful activation.

Use the same procedure to adjust the panel microphone VOX level, using the Panel Mic key and the panel mic VOX level control.

The Headset and Panel Mic keys on the TELEX US-2000 select one of three modes of microphone operation:

Latched Mode:

• Tap the key once to turn the microphone on. The key will glow green.

• Tap the key again to turn the microphone off.

Momentary Mode:

• Press and hold the key to momentarily turn on the microphone.

• Release the key to turn the microphone off.

VOX Mode:

• With the microphone off, tap the key twice to turn on VOX mode. The key will glow orange when no audio is present.

• The key will turn green when you talk into the microphone.

• Tap the key once to turn off VOX mode.

All Talk Function:

The All Talk function allows you to talk on all attached channels simultaneously.

1. Select either the Headset or Panel Mic.

2. Press and hold the All Talk key to talk on all US-2000 and connected ES-4000 channels at once. The key will glow green while pressed.

PA Function:

The PA function allows you to talk over a public address system connected to the P.A. output jack on the rear of the TELEX US-2000.

1. Select either the Headset or Panel Mic.

2. Press and hold the PA key to talk on the public address system. The key will glow green while pressed.

The Mic Kill key on the TELEX US-2000 controls three separate features:

1. Microphone Kill Feature:

This sends a signal to turn off activated microphones on other intercom stations on a selected channel.

• Tap the Mic Kill key once. The key will blink green.

• To turn off microphones on a specific channel, press the Talk or Listen key for that channel.

• To turn off microphones on all channels, press the All Talk key.

• Tap the Mic Kill key again to exit.

2. Program Kill Feature:

This allows program audio to be individually disabled on each channel.

• Press and hold the Mic Kill key. The key will glow green and the current status will be displayed (if a Talk key is lit, program audio is enabled on that channel).

• Press a Talk key to enable or disable program audio on that channel.

• Tap the Mic Kill key to exit.

3. Headset Audible Call Alert Feature:

This enables or disables an audible beep in the headset for incoming calls.

• Press and hold the Mic Kill key. The key will glow green.

• Current status is displayed: if both Call keys are lit, the alert is enabled.

• Press either Call key to enable or disable the audible call alert on both channels.

• Tap the Mic Kill key to exit.

Talk Keys:

With a microphone selected (Headset or Panel Mic), the Talk keys operate in two ways:

• Latched Mode: Tap the key once to talk (key glows green). Tap again to stop.

• Momentary Mode: Press and hold the key to talk. Release to stop.

Listen Keys:

The Listen keys also operate in two ways:

• Latched Mode: Tap the key once to listen (key glows green). Tap again to turn off.

• Momentary Mode: Press and hold the key to listen. Release to turn off.

Call Keys:

• Call Receive: When there is an incoming call signal, the key blinks red. To respond, turn on the Talk key for that channel and begin talking.

• Call Send: To send a call signal, press and hold the Call key for the desired channel until a verbal response is received. The Listen key for that channel automatically turns on when the Call key is pressed.

Each channel of the TELEX US-2000 must be terminated to prevent audio oscillations. While termination is provided by a Telex® power supply, external termination must be installed when a channel is:

• Used in a “dry-line” (non-powered channel) application.

• Unused and un-powered.

To install external channel termination, connect a 300Ω resistor across pins 2 and 3 of the intercom channel connector (either CHN1 or CHN2) at the rear of the US-2000.

To access the internal switches, jumpers, and adjustments, remove one screw from the top of the cover and two screws on each side.

Important: To activate a changed switch or jumper setting, you must either perform a RESET (press All Talk and Listen 1 simultaneously) or cycle the power on and off.

To use the TELEX US-2000 with Clear-Com® equipment, make the following internal switch and jumper changes:

• SW1 (BAL/UNBAL): Must be placed in the UNBAL position.

• J17 (Clear-Com/Audiocom® Mic Level Select): Must have pins 1 and 2 shorted.

• J21 (DC call enable/disable): Must have pins 2 and 3 shorted.

After changing the settings, perform a RESET or cycle the power for the changes to take effect.

To allow the audio from each channel to go to separate powered speakers, make the following internal jumper changes on your TELEX US-2000:

• J22: Must have pins 1 and 2 shorted.

• J23: Must have pins 1 and 2 shorted.

• J24: Must have pins 2 and 3 shorted.

After changing the settings, perform a RESET or cycle the power for the changes to take effect.

The internal SW2 DIP switches on the TELEX US-2000 control various functions as detailed in the table below.

NOTE: When the Program Interrupt feature is enabled for a channel, program audio is shut off on that channel when the Talk key is pressed. If the Program Kill feature is enabled for a channel, the Program Interrupt feature will have no effect on that channel.

The internal jumpers on the TELEX US-2000 configure various operational parameters. The Balanced/Unbalanced Switch (SW1) should be set to the balanced (BAL) position for Audiocom® systems and unbalanced (UNBAL) for Clear-Com® systems.

* For no pins shorted, the jumper is placed on one pin only.

The following adjustments are accessible either internally or from the underside of the TELEX US-2000.

Return Cancellation Adjustments (R187, R188):

These are adjusted at the factory to cancel audio output that may be reflected from the line. They should only require adjustment if the channel impedance or capacitance changes significantly. To adjust:

1. Connect a powered speaker (set for full volume).

2. Enable the TEST SIGNAL on the desired channel.

3. Adjust the appropriate Return Cancellation control to minimize the signal volume on the speaker.

Limiter Adjustment (R198):

This is factory-set for 1 Vrms audio output to the line. If the microphone input is higher than 4 mVrms, adjust the pre-amp Limiter to reduce clipping of the audio output signal if necessary.

Mono Headset Connector (Type: XLR-4M)

• Pin 1: Headset microphone low

• Pin 2: Headset microphone high

• Pin 3: Headphone high

• Pin 4: Headphone low

Panel Microphone or Stereo Headset Connector (Type: NTRK-8F)

• Pin 1: Panel microphone low

• Pin 2: Panel microphone high

• Pin 3: 12 VDC

• Pin 4: Headset microphone high

• Pin 5: Right headphone high

• Pin 6: Right headphone low

• Pin 7: Left headphone high

• Pin 8: Left headphone low

Program Inputs (Type: DB9F)

• Pin 1: Ground

• Pin 2: Program 1 input low

• Pin 3: Program 2 input low

• Pin 6: Program 1 input high

• Pin 7: Program 2 input high

• Pins 4, 5, 8, 9: NC (Not Connected)

P.A. Output (Type: 1/8-inch Stereo Phone Jack)

• Unbalanced Wiring: Tip: PA output high, Sleeve: Common

• Balanced Wiring: Tip: PA output high, Ring: PA output low, Sleeve: Common

Speaker Outputs (Type: RCA Phone Jack)

• Tip: Speaker output high

• Sleeve: Common

Intercom Channel Connectors (Type: One XLR-3M and XLR-3F pair per channel)

• Audiocom® Mode (SW1 set to BAL): Pin 1: Common, Pin 2: Intercom audio low and +24 VDC input, Pin 3: Intercom audio high and +24 VDC input

• Clear-Com Mode (SW1 set to UNBAL): Pin 1: Common, Pin 2: +24 VDC input, Pin 3: Intercom audio high

Expansion Out (Type: 2.0 mm stereo jack)

• Tip: Talk output

• Ring: Listen input

• Sleeve: Common

External Power (Type: 2.0 mm jack)

• Internal pin: positive (+)

• External shell: negative (-)

The following table provides a quick reference for common operations on the TELEX US-2000 and associated ES-4000 units.