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Baldwin Boxall BRX, BTX Operating instructions

  • Hello! I've reviewed the technical details for the Baldwin Boxall SIMPLEX P.A. Public Address System. This document outlines the system's components, including a SEND unit that gets powered from the local amplifier's 100V line and a RECEIVE unit that needs 240V AC for power. It provides specific technical information, such as impedance, output levels, and frequency responses. I'm ready to answer your questions about this system's features and technical specifications.
  • What are the two main units of the system?
    How is the SEND unit powered?
    How is the RECEIVE unit powered?
    What is the landline output impedance of the SEND unit?
Baldwin Boxall Communications Ltd.
Wealden Industrial Estate, Farningham Road
Crowborough, East Sussex, TN6 2JR
Telephone: 01892 664422 Fax: 01892 663146
Website: www.baldwinboxall.co.uk
Email: mail@baldwinboxall.co.uk
IBRXBTX
Issue 3 10/01/2003
ECR 1427
SIMPLEX P.A. SYSTEM
Technical Details
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Issue 3
SIMPLEX PUBLIC ADDRESS SYSTEM
(British Telecom Approval Number - NS/2405/2/E/022890)
The unit consists of two approved enclosures, one acting as a SEND unit which derives it’s power
from the 100 volt line from the local amplifier. The second enclosure houses the RECEIVE unit which
needs to be locally powered from 240V A.C.
SEND OR TRANSMIT UNIT
Landline output impedance @ 1KHz 600 Ohms
Landline output level for 25 volt input -12.5 dBM
Landline output level for 100 volt input -8 dBM
Frequency response @ 15 volt input 200Hz & 3KHz @ -3 dB
RECEIVE UNIT
Landline input impedance @ 1KHz 600 Ohms
Output level with -15dB line input: LINE 0.775V (0dB)
MIC 4mV
Output impedance @ 1KHz: LINE 600 Ohms
MIC 22 Ohms
Max. Output Level: LINE 3.25V
MIC 17mV
Frequency Response 250Hz to 6KHz @ -3dB
Crosstalk voice switch threshold -46dBM
Maximum DC signal current 15mA
Maximum landline DC resistance return path 2 KOhms
Signal input 220 - 240V A.C. @ 50 - 60Hz
Note : If the BTX (SEND) is not connected to the BUSY output of the Local PA Amplifier it will be
necessary to remove the relays from both the BTX and BRX units.
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Issue 3
SWITCHED +24V
0V
100V LINE
LOCAL PA
AMPLIFIERTX UNIT
LOCAL PA
SPEAKERS
230V 50/60Hz
B.T. LINE
PROTECTION
EARTH
PROTECTION
EARTH
RX UNIT
LINE INPUT
ACCESS
SPEAKERS
REMOTE PA
AMPLIFIER
REMOTE PA
CLOSED WHEN
TX UNIT
ACCESSED
BTXBRX
A Typical Simplex Public Address System
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