Symbol for the unit of power, the watt | Telex 38109-977 guide

A unit of electrical power. One watt is the power delivered by one volt at a current of one ampere in a DC circuit, and one volt at one ampere with a phase angle of 0 degrees in an AC circuit.

A graphical representation of a varying quantity. The x (horizontal) axis usually represents time and the y (vertical) axis usually represents amplitude, energy, or power.

Equal noise energy per hertz.

A microphone cover designed to reduce extraneous noises caused by gusts of wind. Also useful for reducing pop from speech plosives such as “b”, “p”, and “t”.

An intercom or telephone line that carries both audio and DC voltage / current. As opposed to a dry line that carries only the audio.

The symbol for volt-ampere. A volt-ampere describes the demand on the power line without regard to power factor or true power. This figure is more helpful in determining the maximum load on a circuit, that has a given ampere rating.

The term for electrical potential of electromotive force. See IR drop.

Volume Units.

Used to show the relative levels of signals. A change of one VU is a change of one dB. VU meters have their 0 VU point referenced to different levels. This level may be 0 dBm, +4 dBm (Recording Industry), +8 dBm (Broadcast Industry). In addition, correct calibration is further involved. The VU Meter has certain characteristics tailored for monitoring sound. Generally speaking the audio peaks are 10 dB above the indications shown on a standard VU meter due to the lag of the meter. Some VU meters are combined with peak reading meters. Levels stated in “VU”s generally apply to program material. Readings in dBm generally apply to a steady state sine-wave.

supply operates a string of belt pack or other user stations in an isolated, balanced mode. The balanced system is transformer coupled into the regular unbalanced system.

V

VThe symbol for volt.

VA

Voltage

Voltage Drop

VU

VU Meter

W

WThe symbol for the unit of power, the watt.

Watt

Wave Form

White Noise

Windscreen

Wet Line

X

Y

Z

150 H a n d b o o k o f I n t e r c o m S y s t e m s E n g i n e e r i n g

Image 164

Telex 38109-977 manual Symbol for the unit of power, the watt

Contents

Handbook of Intercom Systems Engineering Fine Print Table of Contents Design of Party-Line Design of Wireless Introduction to Matrix Determining Intercom Needs Page Page List of Figures Wireless Intercom Interfaced to Matrix Intercom Preface Page About the Authors Page Introduction Party-Line Systems Wireless Systems Matrix Systems Accessories Wireless Intercom Examples Example of Interfacing a TW System to a Matrix System Before We Begin Matrix Rest Of The Book Tally Party-Line PL systems / Conference Line Intercom Systems Two-WireSome Definitions Short History Present Day Systems and Manufacturers Brand Name Manufacturer System Components and Their Function Belt Pack Headset User Station Functional Description Some Technical Notes About The Stations Above Speaker User Station Functional DescriptionMaster Stations Five pin XLR How Each System WorksFour pin XLR Speaker User Stations System PoweringHeadset User Stations Call Lights Outstanding Features of Each SystemCabling Limitations of Each System SummarySome Definitions Short History System Components and Their Function How Each System Works Outstanding Features of Each System Limitations of Each System Audiocom intercom concept RTS TW intercom concept Application 1 Generic Single Channel Systems OverviewDefining And Meeting Your Needs Audiocom Party-Line Intercom Equipment Listing #1 Generic single channel Audiocom system Clear-Com Party-Line Intercom Equipment Listing #1 Generic single channel Clear-Comsystem Application 2 Two-Channel System TV, School, Cable RTS TW Party-Line Intercom Equipment Listing #1 Audiocom Party-Line Equipment Listing #2 Clear-Com Party-Line Equipment Listing #2 Application 3 Theater System RTS TW Party-Line Equipment Listing #2 RTS TW Party-Line Equipment Listing #3 Audiocom Party-Line Equipment Listing #3Clear-Com Party-Line Equipment Listing #3 Application 4 Training Systems Audiocom Clear-Com Clear-Combased training intercom system RTS TW Application 5 Medium System for Television Medium intercom system for television IFB System One Way Communications System How an IFB WorksStudio and Some Field Applications Field Application, Sports Connecting Interfacing to Other Communications Systems Field Application, ENG Electronic News Gathering Typical Interfacing Problem Interfacing Issues Level Problems Signal / Data ConversionModes Call Light Alternatives for Interfacing to Television Cameras Problems in Interfacing to CamerasInterfacing Practice Some Practical Considerations Headset Cable Lengths Wiring Practices/Workmanship Standards Headphone ImpedancesExtended Range On Part Or All Of The System Unbalanced vs. Balanced Cable Considerations Crosstalk Through a Common Circuit GroundCrosstalk Through a Mutual Capacitance Of Two Conductors Low Crosstalk Approach To Interconnection Cooling Requirements Temperature Range ConsiderationSystem Current/System Capacitances/Loading Defining and Meeting Your Needs Magnetic Fields Hum ProblemsMoisture / Contamination Protection Some Practical Considerations Connecting Interfacing to Other Communications SystemsIFB System One Way Communications System Page Page Introduction to Matrix Intercom Systems Definitions KP-32 is a good example of an advanced user station keypanel History of Matrix Intercoms Example of Matrix Ports X X X X X X Number of Users Number of Crosspoints Page Page Modern Day Matrix Intercoms Conventional Matrix vs. TDM Matrix Configurability Special ConsiderationsAdvantages Size Ancillary Functions Conference or PL described above More Complex Ancillary Functions Typical User Station KeypanelPage Complexity DisadvantagesCost You are in your kitchen QUICK, multiply 347.2 times Page Page Back-to-Basics RTS Matrix Intercom Systems Typical Adam Matrix Connections To Begin Let’s get startedStudio a Floor Control Room OtherPage Page Cable Considerations RJ12 Modular Plug Polling Issues Audio and Data Considerations Very Large Systems, Split Operation and Trunking A Comparison of Relative System Sizes Separate Studios, Separate Intercom Fixed Trunking Page Independent Matrices in 2 Studios Page Cascaded Trunking Signal Formats Interfacing Interconnecting Matrix, PL, and Wireless Systems TW and Matrix Signal Flows 10 Wireless Intercom Interfaced to Matrix Intercom + + Software Considerations 12 TW to Matrix Interface Adam and Adam CS Basic Components Adam Page Introduction to Wireless Intercoms History of Wireless IntercomsPage Modern Day Wireless Intercoms First beltpack based wireless intercom system An example of a modern day wireless intercom system Page Ntsc Channel Configuration Chan Start Video Chroma Audio Chan Start Video Chroma Audio Page Page Design of Wireless Intercom Systems Field An example of wireless transmission and reception An example of reflected RF waves Waves that are in phase combine to form a larger wave An example of combining waves that are not 180 out of phase Interference 3A 2B = C 2A B = C+ C = D 10 Transmitter block diagram Transmitters and Receivers 11 Receiver block diagram 12 Good linearity is a must for faithful signal reproduction Antenna & Cable Considerations Page 14 An example of a Yagi antenna Page Installation Coaxial Cable Loss ChartPage Page Page Determining Intercom Needs Conference Versus Point-to-Point RequirementsPage Fixed vs. Mobile Requirements General Overview Determining Intercom Needs, two-wire, four-wire, or both? PS15 Power Supply/MCP2 Rack KitSmall Studio or ENG Vehicle MCE325 Modular Programmable Station Headsets and Earsets not shown Medium Sized Studio and Mobile IntercomTW5W Splitter IFB325 Talent User Station Two-wire Case Medium Intercom 803-G1G5 Master Station PS31 Power Supply BOP220 Connector Translation AssemblySystem Interconnect SAP1626 Source Assign Panel Four-wire Case Medium Intercom Zeus DSP2400 Matrix KP96-7 KeypanelTIF-2000 Intelligent Telco Interface MKP4-K Modular Keypanel IFB828 IFB Power Supply PS15 Power SupplySSA324 System-to-System Adapter SAP612 Source Assign Panel Large Studio or Mobile Vehicle Determining the Makeup of the Intercom Matrix First Step--Determine the SizeUsers IFB Circuits Miscellaneous Second Step--Determine the PanelsCameras Other Considerations in Determining Intercom Needs Maintenance How old is Too Old?Expandability Interoperability Budget Glossary AWG O s s a r y CCU CPS Crosstalk Current Current Sources DSP EFP EIA GND Gpio Green Room Ground Ground Loop Potential Ibew IFB IR Drop Isolation Light Signaling Limiter Line Line Level Matrix Maximum SPL Mho Mic Micro µ Microcontroller NAB Nabet NEC Nema PLL PZM RFI RMS Smpte SPL O s s a r y Symbol for the unit of power, the watt Index IFB ISO STL VHF