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  5. Operating Instructions And Troubleshooting Manual

Lectrosonics M187 Operating Instructions And Troubleshooting Manual

Summary of M187

  • Page 1

    M187 belt-pack transmitter lectrosonics, inc. Rio rancho, nm operating instructions and trouble-shooting guide.

  • Page 2: Introduction

    2 table of contents introduction .................................................................................................. 2 general technical description ............................................................. 3 controls and functions ....................................................

  • Page 3

    3 belt-pack transmitter rio rancho, nm – usa m187 block diagram general technical description the m187 transmitter is comprised of four major functional subsystems: the input compressor, the mic preamp/gain control, the compandor, and the rf transmitter (see block diagram below). The mic preamp is a...

  • Page 4: Controls and Functions

    4 controls and functions input jack the input on the m187 accommodates virtually every lavalier, hand-held or shotgun microphone available. Use a switchcraft ta5f connector on the cord. See the separate sheet titled “m187 input jack configuration” regard- ing the correct connections for various micr...

  • Page 5

    5 belt-pack transmitter rio rancho, nm – usa since the internal circuits are all tightly regulated and the rf output stage has a separate discrete regulator, the transmitter will continue to operate to a battery voltage of 6.5 volts. From 6.5 volts to 6 volts, the transmitter will still operate, but...

  • Page 6: Battery Replacement

    6 battery replacement the m187 transmitter is powered by a standard alkaline 9 volt battery. It is important that you use only an alka- line battery for longest life. Standard zinc-carbon batteries marked “heavy-duty” or “long-lasting” are not ad- equate. They will provide only about 4 hours of oper...

  • Page 7: Operating Instructions

    7 belt-pack transmitter rio rancho, nm – usa operating instructions 1) insert the microphone plug into the input jack, aligning the pins; be sure that the connector locks in. 2) turn the power switch to the “mute” position on the transmitter. The “mute” position allows internal voltages to stabilize...

  • Page 8: Microphone Cord Termination

    8 microphone cord termination 1 2 3 4 5 view from solder side of pins 0.3" 0.15" heatshrink tubing ta5f connector assembly mic cord stripping instructions caution! Do not allow the shield wire to touch any metal part of the connector shell. The shield wire is the antenna on vhf models and poor opera...

  • Page 9: M187 Input Jack Wiring

    9 belt-pack transmitter rio rancho, nm – usa m187 input jack wiring the wiring diagrams shown on the attached sheet represent the basic wiring necessary for the most common types of microphones and other audio inputs. Some microphones may require extra jumpers or a slight variation on the dia- grams...

  • Page 10

    10 rf bypassing some mics require rf protection to keep the radio signal from affecting the capsule, even though the transmitter input circuitry is already rf bypassed (see schematic diagram). If the mic is wired as directed, and you are having difficulty with squealing, high noise, or poor frequenc...

  • Page 11: Troubleshooting

    11 belt-pack transmitter rio rancho, nm – usa troubleshooting before going through the following chart, be sure that you have a good battery in the transmitter the red power led on the transmitter panel should glow brightly. Symptom possible cause transmitter battery led off 1) battery is inserted b...

  • Page 12: Specifications And Features

    12 specifications and features operating frequencies: 150 to 216 mhz rf power output: 50 mw deviation: ±15khz (max) spurious radiation: 55 db below carrier equivalent input noise: -126 dbv input level: nominal 2 mv to 300 mv (before compression) 30 volt max. Input level (including limiter) input imp...

  • Page 13: Service And Repair

    13 belt-pack transmitter rio rancho, nm – usa service and repair if your system malfunctions, you should attempt to correct or isolate the trouble before concluding that the equipment needs repair. Make sure you have followed the setup procedure and operating instructions. Check out the inter- conne...

  • Page 14: Limited One Year Warranty

    Limited one year warranty the equipment is warranted for one year from date of purchase against defects in materials or workmanship provided it was purchased from an authorized dealer. This warranty does not cover equipment which has been abused or damaged by careless handling or shipping. This warr...