The Behnke PA-system/add-on amplifier is a versatile electronic device designed to integrate a Public Address (PA) system with a telephone system, enabling voice announcements and alarm signals through connected speakers. This manual covers models 20-0040, 20-0054, 20-0055, and 20-0056, providing detailed instructions for installation, configuration, and operation.

Function Description:

The core of the system is the 20-0040 basic electronics, which features an integrated ELA (Public Address) adaptation. This allows for easy connection of a PA amplifier to a telephone system, enabling voice announcements via the speaker sets of any telephone connected to the system. Users can also trigger alarm signals (e.g., gong, siren) through the telephone, provided the PA amplifier supports this feature. The 20-0040 includes two relays with potential-free switch outputs (changeover contacts) that can be controlled via DTMF dialing (using a '#' code for configurations, as detailed in the technical manual). An external microphone (such as an ECM-60 electret microphone) can also be connected to the 20-0040 for direct responses.

The 7 Watt add-on amplifiers (20-0054, 20-0055, 20-0056) extend the functionality of the basic electronics by providing additional amplification for speakers. These amplifiers are designed to work in conjunction with various Behnke door intercom stations, enhancing the audio output for broader coverage or louder announcements.

Important Technical Specifications:

20-0040 Basic Electronics:
- Audio Output: 200 mV~ (default status) for connection to a PA system (PA amplifier).
- NF Signal Alignment: Adjustable via a potentiometer (1) for fine-tuning the LF signal. Users must adhere to the technical specifications of the installed amplifier.
- Relays: Two potential-free switch outputs (changeover contacts) controllable via DTMF dialing.
- Power Supply: No additional power supply is required for the 20-0040 when connected to a telephone system, as it draws power from the system.
- Microphone Input: Supports external microphones for response (e.g., ECM-60).
7 Watt Add-on Amplifiers (20-0054, 20-0055, 20-0056):
- Power Supply: 12 V-15 V / 1.2 A (DC).
- Speaker Output: 8 Ohms minimum, 7 Watts.
- Output to Door Intercom: 12 V= for connecting to a door intercom.
- LF Input Signal: Speaker signal from the Behnke door intercom.
- Operation Display: An indicator (5) shows the operational status.
- Potentiometer (6): Used for adjusting settings. This potentiometer should only be adjusted when used with specific Behnke basic electronics models (20-0001E, 20-0014E, 20-0016E, 20-0043E).
- Wire Lengths (for 20-0054):
  - LF signal from intercom to add-on amplifier: Max. 50 m (twisted pair, 0.08 mm² cross-section recommended).
  - Add-on amplifier to external speaker: Max. 3 m (twisted pair, 0.08 mm² cross-section recommended).
  - Power supply (Behnke power supply unit 20-9585) to add-on amplifier: Max. 30 m (twisted pair, 0.08 mm² cross-section recommended).
  - Add-on amplifier to basic electronics (12-15 Volt +/-): Max. 30 m (twisted pair, 0.08 mm² cross-section recommended).

Usage Features:

Configuration (20-0040 PA Operation):
- Set-up Mode: Activated by * and 0000 (security code).
- Volume Setting: Adjusted via configuration step 06 1 to 9#. It is crucial not to use configuration step 07 ("add-on amplifier", built-in 1 Watt add-on amplifier) with the 20-0040, as this can damage the ELA amplifier. The NF level at the LF output is changed by step 06.
- Advanced Configurations: Enabled by 900 1#.
- PA Mode Settings (967):
  - 967 0#: Inactive.
  - 967 1#: Answer a call without a ring-tone but with a beep.
  - 967 2#: Answer a call without a ring-tone and without a beep.
  - 967 3#: Answer a call without a ring-tone but with a beep for the calling party only (V 1.30 or later).
- Exit Configuration Mode: *.
Operation with 7 Watt Add-on Amplifiers (20-0054, 20-0055, 20-0056):
- Volume Setting: For Behnke intercom stations with an external 7 Watt add-on amplifier, the volume is always adjusted via configuration step 06. Again, configuration step 07 must not be used, as it can damage the external add-on amplifier.
- Specific Models (20-0001E, 20-0014E, 20-0016E, 20-0043E):
  - Set-up Mode: Activated by ** and 0000 (security code).
  - Volume Setting: Set to the lowest volume "1" using 06 1 to 5#.
  - Microphone Sensitivity: Set to the least sensitive setting "1" using 912 1 to 4#.
  - Exit Set-Up Mode: *.

Maintenance Features:

Installation:
- All Behnke intercoms and accessories must be installed and serviced by qualified electricians in compliance with safety provisions.
- Before any service or maintenance, devices must be safely disconnected from the power grid (unplug power supply unit) and any other network.
- When mounting speaker modules (1) to the module frame (2), ensure they are within the basic electronics' (3) module housing. Maximize the distance between the speaker and microphone to prevent acoustic feedback. This applies to all Series 20/30 basic electronics.
- For the 20-0055/20-0056, ensure insulation is removed from wire ends when connecting to the basic electronics' 12V+/- terminals.
Acoustic Feedback Adjustment:
- If acoustic feedback occurs with specific Behnke basic electronics models (20-0001E, 20-0014E, 20-0016E, 20-0043E) and external 7 Watt add-on amplifiers (20-0054, 20-0055, 20-0056), follow these steps:
  1. Perform the configuration settings: set volume to lowest "1" (06 1 to 5#) and microphone sensitivity to least sensitive "1" (912 1 to 4#).
  2. If feedback persists, carefully remove the locking varnish from the potentiometer (6) on the add-on amplifier.
  3. Slightly turn the potentiometer clockwise until the acoustic feedback vanishes.
  4. If necessary, re-adjust the volume using configuration step 06 (increase speaker volume) and 912 (increase microphone volume).
General Maintenance Information:
- The manufacturer reserves the right to change products due to technical progress. Products delivered may differ visually from those illustrated in the manual.
- Reproduction of manual content (texts, images, photos) requires express written consent.
- The manufacturer is not liable for errors, content mistakes, or misprints in the manual.
- All products must be used for their intended purpose. Consult a specialist or service department if in doubt.
- Products with a power supply (especially 230 V mains-operated) must be disconnected before opening or installation.
- The manufacturer is not liable for damages resulting from modifications, improper use, storage, or external influences.
- When handling 230 V mains-powered or battery-powered products, observe relevant guidelines (e.g., electromagnetic compatibility, Low Voltage Directive). Work should only be performed by trained technicians.
- Products comply with all technical guidelines and telecommunications regulations applicable in Germany and the EU.

Telecom Behnke 20-0040 - Montage 20-0055; 20-0056

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