Clear-Com PM-220 Instruction And Service Manual

RM-220

2-CHANNEL REMOTE STATION

INSTRUCTION

and

SERVICE MANUAL

Clear-

COlli

Intercom Systems

945 Camelia st. Berkeley, California 94710 510-527-6666

Clear-Com 810193

8/24194

REV

. A

Clear-Com Systems

RM

-220 2-Channel Remote Station

Instruction Manual

PIN 810193

(C) 1990 Clear-Com Systems
All

Rights Reserved

Clear-Com Systems
945 Camelia

St.

Berkeley,

Ca.

94710

U.S.A

While Clear-Com makes every attempt to maintain the accuracy

of

the information

contained in its

product

manuals, that information

is

subject to

change

without

notice.

3

RM-220 2 Channel Remote Station

CLEAR-COM LIMITED WARRANTY

Clear-Com products are warranted to

be

free from defects

in

materials

and

workmanship

for a period

of

one

year

from the date

of

sale.

Clear-Com's sole obligation during the warranty period

is

to provide, without

charge, the parts

and

labor necessary to remedy covered defects appearing

in

products returned prepaid to Clear-Com, 945 Camelia St., Berkeley,

Ca.

94710-1484, U.S.A.

This warranty does

not

cover any defect, malfunction

or

failure

caused

beyond

the control

of

Clear-Com, including unreasonable

or

negligent operation,
abuse, accident, failure to follow instructions in the Manual, defective or im­proper

associated equipment, attempts at modification

and

repair

not

autho-

rized

by

Clear-Com,

and

shipping damage. Products with their serial numbers

removed

or

defaced are not covered

by

this warranty.

To

obtain warranty service, follow

the

procedures described

below

in

IIProced-

ures for Returns

ll

and

IIShipping

to

Manufacturer for Repair

or

Adjustment.

1I

This warranty is the sole

and

exclusive express warranty given with respect to

Clear-Com products.

It

is the responsibility

of

the

user

to determine before pur-

chase that this product is suitable for

the

user's intended purpose.

Any

and

all implied warranties, including the implied warranty

of

merchantability are limited to the duration

of

this express limited warranty.

Neither Clear-Com

nor

the dealer

who

sells Clear-Com products is liable for

incidental

or

consequential damages

of

any kind.

Return Shipping Instructions

Procedures for returns:

-If

repair

is

necessary, contact the dealer

where

the unit

was

purchased.

-If

repair through the dealer is not possible, contact the Clear-Com Custom-

er

Service Department, located at the factory, as directed below.

They

will is-

sue

a Return Authorization Number eRMA).

-Do

not

return

any

equipment to the factory without first obtaining a Return

Authorization Number.

©

Clear-Com Intercom Systems 1994

Rev. A

4

RM-220 2 Channel Remote Station

-Be

prepared

to provide your

companys

name, address,

phone

number,

name

of

person

to contact regarding the repair, type

and

quantity

of

the

equipment, description

of

the defect,

and

the

equipment

serial number(s).

Questions regarding returns for repair should

be

directed to:

Customer

Service

Department

Clear-Com

Intercom

Systems
945 Camelia Street
Berkeley, California 94710-1484
Telephone:

[phone]

Fax: [phone]

Shipping to Manufacturer for Repair

or

Adjusbnent

All

shipments

of

Clear-Com equipment must be

prepaid

via United Parcel Ser-

vice

or

the

best available shipper. The

equipment

should

be

shipped

in

the

original packing container; however,

if

the original container is

not

available,

use

a suitable container that is rigid

and

of

adequate

size.

If

a substitute con-

tainer is used, the equipment should

be

wrapped

in

paper

and

surrounded

with

at

least four inches

of

excelsior

or

similar shock-absorbing material. A de-

tailed description

of

the

problem

or

work

to

be

done

should

be

included.

All

shipments should

be

directed to

the

attention

of

the Customer Service Depart-

ment

and

must include the Return Authorization Number.

Upon

completion

of

repairs, equipment will

be

returned collect via United Par-

cel Service

or

other specified shipper.

NOTICE

ABOUT

SPECIFICATIONS

Performance specifications included in this manual are deSign-center specifica­tions

and

are included for customer guidance

and

to

facilitate system installa-

tion. Actual operating performance may vary.

BEFORE YOU BEGIN .

..

To

get

the

most

out

of

the

RM-220

Main Station, read this manual carefully.

It

will

answer

questions

you

might have

about

the

operation

and

service

of

the

components in the system. Included

is

a Troubleshooting Section that provides

causes

and

possible solutions to problems

you

might

have

with system

and

component

operation. Clear-Com's Customer Service

Department

is available

to

answer questions

not

covered in this manual.

Rev. A

©

Clear-Com Intercom Systems1994

5

RM-220 2 Channel Remote Station

THE CLEAR-COM CONCEPT

Clear-Com

is

a closed-circuit intercom system that consistently provides high­clarity communication in high-noise and low-noise environments. A basic sys­tem consists

of

a single- or multi-channel

power

supply

or

main station con-

nected to various single-

or

multi-channel remote stations,

such

as beltpacks

and

loudspeaker stations.

Clear-Com manufacrures a wide variety

of

both portable

and

fixed-installation

units.

All

are compatible with

each

other. Clear-Com intercom systems

can

also interface with

?ther

communication systems

and

devices.

Clear-Com stations are interconnected with two-conductor, shielded micro­phone

cable, using 3-pin

XLR

connectors.

One

wire carries

the

DC

power

(28-30 volts) from a main station or power supply to all remote stations,

and

the

other wire carries 2-way (duplex) audio information. The shield acts as a

common

ground.

One

termination

(per

channel)

is

needed

throughout the in-

tercom network,

and

is

usually located

in

the

main station or

power

supply.

Clear-Com

is

a distributed amplifier system; each main

and

remote

station

houses its

own

mic preampliller, headset

or

speaker

power

amplifier,

and

signaling drcuitry. Low-impedance mic input lines (200 Ohms)

and

specially

designed circuitry make Clear-Com channels virrually immune to

RFI

and dim-

mer

noise.

Clear-Com main stations, power supplies

and

certain remote stations

each

have

an

auxiliary program input with its

own

volume control, which allows

an

exter-

nal audio source to

be

fed to the intercom system.

Visual Signal Circuitry

(CALL

Lights), a standard fearure

on

most main

and

re-

mote stations, allows the user to attract the attention

of

operators

who

have re-

moved their headsets.
Depending

upon

the type

of

main

and

remote stations selected

and

assuming

that

enough

DC

power

is

available, a maximum

number

of

remote stations

from

10

(all speaker stations) to 30 (all headset stations)

can

be

distributed

along a mile

of

wire. Remote stations bridge the intercom line

at

a very high

impedance (>10 KOhms), and place a minimum load

on

the line.

The

audio

level always remains constant, and does not flucruate

as

stations leave

and

join

the

network.

© Clear-Com Intercom Systems 1994

Rev. A

6

RM-220 2 Channel Remote Station

DESCRIPTION

The

"PL-Pro"

RM-220

is

one

of

a series

of

professional intercom stations specifi-

cally designed for the broadcast industry. This 2 channel,

one

rack

space

sta-

tion

is

ideal for

ENG

and

EFP

trucks, production studio consoles,

and

small

TV

facilities. The station can

be

tailored

to

your

needs through it's programmable

"Talk"

button options. The

RM-220

is

compatible with all Clear-Com Party-Line

intercoms,
The station also incorporates a single channel program interrupt system (lFB)

in

the

station. When activated,

one

or

more stations

can

interrupt

the

program

to a talent with Clear-Con's wired

or

wireless talent receivers. Direct connec-

tion

to

Clear-Corn's

IFB

system

is

easily accomplished through a 1/4 inch

phone

jack

on

the rear panel intended to directly connect

to

a Clear-Com

MA-4.

The

RM-220

remote

speaker/

headset station allows selectable two channel

talking

and/or

listening

on

a Clear-Com Intercom System.

The

operator can

communicate

on

either

of

the channels separately

or

on

both

at once. Illumi-

nated dual action talk buttons are electronic momentary

or

latching.

The

latch-

ing feature may

be

disabled if desired. Also the talk buttons can

be

remote

controlled for footswitch

or

other use. Monitoring activity

is

possible through

the

speaker

or

headset

or

both at once.

The

RM-220

features Visual

Call

Signaling to attract the attention

of

operators

who

have removed their headsets

or

turned off their speakers.

This station accepts dynamic headsets. The station accepts two different
lengths

of

plug-in gooseneck microphones,

9"

and

18",

to

allow for different

operating locations/positions.

The station's speaker can

be

turned

on

or

off

by

a convenient front

panel

switch

when

private conversation via the headset

is

desired. A "speaker dip-

ping" circuit will give you

an

additional amount

of

acoustic output before feed-

back. This feature helps

to

reduce feedback

when

stations are placed

in

close

proximity

to

each other. The station accepts a balanced Program

input

for

mOnitoring external audio in the headset

or

speaker. Individual sidetone con-

trols for

each

channel allows the operator

to

vary the level

of

his/her

own

voice as heard in the headset/speaker.

Rev. A @ Clear-Com Intercom Systems1994

7

RM-220 2 Channel Remote Station

"Studio Announce" allows control

of

a paging

speaker

in

a studio. A front

pan-

el

button

activates this function

and

an

assodated

relay.

The

RM-220

installs

in

a standard

19"

equipment

rack, using

only

one

rack

space. The

station provides

two

3-pin,

XLR

connectors for

Input

and

loop-

through

on

each

channel.

TECHNICAL SPECIFICATIONS:

CONTROL SYSTEM:

CMOS Digital Logic

and

Signal Switching

HEADSET MICROPHONE PRE-AMP:

Dynamic Headset Input

Impedance

---

- 1 KOhms

Input Level - 55

dBv*

nominal

Frequency Response: 250 Hz

to

12 KHz,

contoured

for intelligibility.

Gain from Headset

to

Intercom Line:

--

+41

dB

PANEL MICROPHONE PRE-AMP:

Input

Level

------------

45

dBv*

nominal

Frequency Response: 250 Hz

to

12 KHz,

contoured

for intelligibility.

Gain from Panel

Mic

to

Intercom

Line:

--

+31

dB (adjustable)

SPEAKER AMPLIFIER:

Load Impedance:

----------

16

Ohms

Output

Level: at least 4 watts

Distortion:

<0.2%

THD at 1 KHz

Frequency Response: 200-18KHz +/-2dB

HEADPHONE AMPLIFIER:

Load Impedance:

----------

greater

than

50

Ohms

Output

Level: at least +20

dBv*

across 600

ohm

Distortion:

------------

<0.2% THD

at

1 KHz
Frequency Response: 200-18KHz +/-2dB
Gain from Intercom Line: +37 dB

PROGRAM INPUT:

Input

Level

Ref.:

----------

-10

dBv*

Input

Impedance

: >40 KOhms

Frequency Response: 150 Hz to 15 KHz

© Clear-Com Intercom Systems 1994

Rev. A

8

RM-220 2 Channel Remote Station

INTERCOM LINE DRIVE/RECEIVE CIRCUITS:

Impedance, Output Load:

------

> 10 KOhms (200Hz - 10 KHz)

Level, Line (200

ohm

load): -9

dBv*

(nominal) +5dBv (max

before clip)

Sidetone Null Capability:

-------

>

25

dB (200Hz - 10 KHz)
Crosstalk, Station Induced Ch. to Ch.: >60 dB
Noise,

SN

Ratio

in

Listen Channels: >60 dB

LINE LEVEL OUTPUTS:

SA

(Announce)

Type

Balanced

Impedance

---

-~---

~

600

ohms

Level 0 dBv

IFB/HOT

MIC:

Type

--------

--

---------

Unba~nced

Impedance

---------

600

ohms

Level 0 dBv

STANDARD CLEAR-COM SYSTEM SPECIFICATIONS:

Usable Line Quality:

--------

> 100 Stations

Total Line Length

on

One

Channel > 5000 feet

CONNECTORS:

Intercom:

----

--

------

4

XLR-3

(2-CH

A,

2-CH B)

Accessory DB-15F

Program Input
SA

output

Foot Switch Logic Inputs

IFB/HOT

MIC.

--

---

-----1/4

inch

Phone

Jack

POWER REQUIREMENTS:

Source Intercom Line
Voltage

------------

20

- 30

VDC

Current 65

rnA

idle, 120

rnA

average

PHYSICAL SPECIFICATIONS:

Dimensions:

-------------

19"W x 1.75"H x 7 ..0D

(483mm x 44.5mm x 178mm)

Weight:

------------

3.6 lbs 0 .6 Kg)

Operating Temperature Range: 32-122° F

CO-50°

C)

• -

OdBv

= 0.775 volts

RMS.

(Specifications subject to change without notice.)

Rev. A

© Clear-Com Intercom Systems1994 .

9

RM-220 2 Channel Remote Station

INSTALLATION

This section discusses the installation

of

the

RM-220

in

an

intercom system.

Typical applications, overall installation theory,

and

detail

of

each

connector,

and

adjustment

of

the

RM-220

are discussed.

INSTALLATION OVERVIEW

This section describes the Clear-Com concept in intercom line interconnection.
The

following subjects are discussed:

• Intercom Line Connection

• Line Termination

• Station Powering

• Cable Considerations

Intercom Line Connection:

The

RM-220

provides a male

and

female

XLR-3

connector for

each

intercom

line that

are

"looped through".

Line Termination:

The

fundamental concept

of

Clear-Com Party-Line intercom is that all stations

provide high impedance current sourced signals into a single

common

system

termination.

The

line drivers in a station have a source

impedance

greater

than

10 KOhms.

The

receive

or

"listen" section

of

stations contain a 'hybrid null' circuit that at-

tempts

to

reject (null) any "talk" signal being sent

by

that station

on

that chan-

nel.

The

'hybrid null' circuit

depends

on a known

impedance

on

the

intercom

line

to

accomplish this. Variations in impedance

on

the

line

upset

the

'null'.

CAUTION:

All

Clear-Com Intercom lines must

be

terminated.

Care

must

be

taken

not

to

fail

to

terminate

or

to

'double' terminate a line.

All

unused

in-

tercom inputs must

be

terminated to

keep

the

line drive circuits stable.

The

RM-220

does

not

provide termination

on

the intercom line. Clear-Com

main stations

and

power

supplies provide switch selectable termination net-

works

on

all intercom

output

lines. It

is

up

to

the

user

to

determine

where

the

termination will

be

provided.

An

unterminated line will cause excessive levels,

possible oscillation

of

line drivers,

and

sever unbalance

of

hybrid null net-

works. A

double

or

multiple terminated line will cause

low

levels

and

sever

unbalance

of

hybrid null circuits.

©

Clear-Com Intercom Systems 1994

Rev. A

10

RM-220 2 Channel Remote Station

The

termination

of

an

intercom line (or channel) is a 220

Ohm

resistor in series

with a 4.7 KOhm that

is

paralleled with a

10

uF capacitor.

Station Powering:

The

RM-220

needs +20 to

+30

volts between pins 1

and 2 of

the intercom con-

nectors. Typical Clear-Com systems are powered

by

a Main Station

or

a Power

Supply.
Clear-Com

power

supplies can

be

paralleled to increase the

number

of

RE-

MOTE

STATIONS

that can

be

operated in a system.

Cable Considerations:

The

Clear-Com intercom line

is

intended to run

on

a shielded twisted pair

of

cable

per

channel

of

intercom.

One

conductor carries full duplex ("two-way")

audio, the

other

conductor carries the

DC

power

for remote stations.

The

shield

is

used

for ground return for audio

and

power.

When

choosing inter-

connect cable,

keep

the following considerations in mind:

1

DC

resistance

of

the ground

or

common conductor affects crosstalk.

For runs longer than 500 feet

do

not

use wire smaller

than

20 gauge.

2 The capacitance

of

the interconnect cable affects system frequency

response

and

sidetone stability. Total capacitance should

not

be

greater than 0.25

uFo

Portable Installation Cable: Practical cable for portable system interconnec­tions

is

flexible, two-conductor, shielded microphone cable. For runs less than

500 feet a cable

made

of

24

gauge wire is acceptable. For runs longer than 500

feet

use

a 20 gauge cable

or

larger.

Permanent

installation Cable: Vinyl-jacketed shielded pair

is

the cable

of

choice for permanent installations. Use a low-capacitance

20

gauge

wire for

short runs

(under

500 feet) and 18 gauge cable for runs greater

than

500 feet.

Placing the cable in conduit

is

recommended but not necessary.

Multi-pair cable that is indiVidually shielded

is acceptable for use in multi-

channel systems. For cross-talk considerations the shields must

be

tied togeth-

er

on

both

ends

of

the cable to

produce

the lowest possible

DC

path

for

ground

return.

Rev. A © Clear-Com Intercom Systems1994

11

RM-220 2 Channel Remote Station

DESCRIPTION OF CONNECTORS

Headset Connector (Front Panel)

NOTE ABOUT

HEADSETS:

The following

is

a description

of a recommended

headset.

Mic

Type - Dynamic

Wiring: Pin 1 - mic

common

Impedance - 150-250 Ohms Pin 2 - mic

hot

Output

--

-55dB Pin 3 -

headphone

common

Headphone

- Dynamic

Pin 4 -

headphone

hot

Impedance - 50-2000 Ohms

Panel Mic Connector (Front Panel)

Clear-Com provides two plug-in panel microphones for

use

on

the

RM-220

.

The

GM-9

is 9 inches long and

GM-18

is

18

inches long.

The

microphone

is

of

the electret type. The microphone has a builtin 1/4 inch

phone

jack for a con-

nector. A mating receptical is mounted

on

the

RM-220.

To

install a

GM-9

or

GM-18

panel mount microphone

use

the

following steps :

1 Check the set screw in the mic mounting flange

to

make

sure

it is

clear

of

the threads in

the

bushing.

2 Screw the microphone into the bushing

hand

tight.

3 Set the set screw

on

top

of

the bushing

to

lock the mic

in

place.

Intercom Line Connectors (Rear Panel, XLR-3 2 male & 2 female)

The

RM-220

has a male and female pair

of

XLR-3

connectors for

each

intercom

line.

The

male-female pair

of

connectors are wired parallel

and

intended

for

loop-thuough connection.

The

pinout

of

the Intercom Connectors is as follows:

Ground (Shield)

• Pin

1

• Pin 2

Power (+20

to

+30

VDC)

• Pin 3 Audio

©

Clear-Com Intercom Systems 1994 Rev. A