Comtek Communications Technology M175 Personal body-worn communication transmitter User Manual C 175rpt tableofcontent wpd

Comtek Communications Technology Inc Personal body-worn communication transmitter C 175rpt tableofcontent wpd

User Manual

M-175 OPERATOR’S MANUAL (PRELIMINARY)357 West 2700 South • Salt Lake City, Utah 84115 • Phone: (800) 496-3463 • Fax: (801) 484-6906 • http://www.comtek.comM-175PersonalCommunicationTransmitter
© 2007 COMTEK® All rights reserved.Printed in the U.S.A. 0107M175TABLE OF CONTENTSIntroduction ...........................................................Setup ...............................................................................Controls ..................................................................Battery Removal / Replacement ......................................Battery Charging ......................................................Auxiliary Audio Input Operation ...................................Snap-On Belt Clip .................................................Frequency Selection ..............................................Frequency Information .........................................Optional Accessories ............................................Specifications .........................................................Warranty and Service ..................................................123456-7789101112
INTRODUCTIONPage 1The M-175 transmitter offers theultimate performance andversatility for applications whereone-way personal communication isrequired. This compact, personaltransmitter is ideal for instructors andpresenters who must communicatewith persons some distance away orin a noisy environment.The M-175 incorporates the latest digitaland analog technologies to produce lowresidual noise, wide dynamic range, andextended frequency response renderingthe most natural sound possible from apersonal communications system.The audio processing circuit producesfull fidelity frequency response from100 Hz to 10 kHz in the compandedor non-companded mode toaccommodate a greater variety ofreceivers. Operating under F.C.C.Regulation Part 90 allows agreater transmission range andreliability than is customarywith 72-76 MHz systems.M-175PersonalCommunicationTransmitter
Setupa. Check to ensure that the M-175 transmitter’s radio frequency channel isthe same as the associated COMTEK receiver’s channel.(Channels are indicated by the rotary channel selector switches on the backof the transmitter. See page 8.)b. Open the battery door cover on the transmitter (see page 4) andinsert a new nine volt alkaline battery (Eveready E522 or equivalent).This type of battery will offer up to 16 hours of operation. Replace the batterybefore every use if the demand for fail-safe operation outweighs battery cost. The useof carbon batteries is not recommended.NOTE: If a rechargeable battery is to be used, ensure that it has beenallowed to charge at least twelve hours to bring it to full charge(see page 5 for battery charger instructions).c. Connect the microphone to the transmitter by inserting the microphoneplug into the receptacle on the top of the transmitter. The transmitter isoperating when the transmitter power switch is turned on and the batterystatus/on indicator illuminates.NOTE: The 48-inch microphone cord also functions as part of thetransmitter’s antenna system. For optimum performance, this cordshould be fully extended. Coiling or bunching the microphonecord may reduce the range of the transmitter. The transmittershould be carried by the snap-on belt clip (included) or in a pocketor belt-clip pouch.d. In a situation where an extremely loud voice or a very soft voice is used, itis necessary to adjust the audio input gain control while observing the audio“voice” level modulation indicator. A full bright LED indicates full audiocompression at 100% modulation. For best performance, the audio inputgain should be adjusted for some low level LED luminescence duringnormal audio levels with occasional full bright peaks indicating 100%modulation.M-175 SETUPPage 2
Page 3M-175 CONTROLSn COMPAND AUTO / OFF SWITCH: This switch overridesthe automatic selection of the companded channels tonon-companded operation.o CHANNEL SWITCHES: These rotaryswitches are used to set the transmitter to thedesired operating frequency.(See page 9 and 10 for frequency selection chart.)p BATTERY COMPARTMENT: Thebattery compartment features a hingedbattery cover and an alignment system thatensures proper battery polarity. Batteryinstallation and removal is facilitated by simplymanipulating the bottom of the battery.q AUXILIARY AUDIO INPUT JACK:Allows transmitter to use line level, earphonelevel, or fixed AUX as an audio source.r AUDIO “VOICE” MODULATION INDICATOR:This indicator is used in making adjustment with theAudio Input Gain Control.s MIC / ANTENNA JACK: This jack accepts anelectret type microphone having a 48” long cord witha micro-mini 2.5mm mono plug. The microphone cordfunctions as part of the transmitter’s antenna systemand must be in place for auxiliary audio input operation.If microphone function is not necessary, the optionalmicrophone switch should not be on for this operation.t POWER / BATTERY STATUS INDICATOR: This LED indicator will illuminatecontinuously when the unit is on, indicating normal operation. When the battery voltagedrops below 6 volts, the LED will flash rapidly, indicating that a new battery is needed.u OPTIONAL MIC SWITCH: This switch turns off the microphone without turning offthe transmitter carrier.v AUDIO INPUT GAIN CONTROL: This is a microphone and AUX level input gaincontrol. This control is used with the “Voice” modulation indicator.w ON / OFF SWITCH: This switch turns the transmitter on and off.
Page 4Low Battery IndicatorThe LED on the top of the transmitterindicates the status of the battery aswell as indicating that the unit is turnedon. When the transmitter is turned on,the LED illuminates. If the battery is low,the green LED will blink rapidly to warnyou that the battery will soon be dead.Replace a low battery immediately.M-175 BATTERY REMOVAL / REPLACEMENTPull back battery door latch and allow batterycover door to spring open. To remove battery,simply manipulate the bottom of battery out ofthe compartment and remove.To insert battery, face batterywith negative terminal in line withlarge hole in battery compartment,press battery into compartment and closebattery door until it snaps shut. Note: It is notpossible to put battery in backwards.Battery indicator LEDBattery Removal / Replacement
Page 5M-175 BATTERY CHARGINGBattery Charging1. Make sure that a seven cell 9 volt Ni-MH rechargeable battery is used with a minimum of 200 mAh capacity. (Alkaline batteries must not be charged.)2. Make sure the M-175 is turned OFF.3. Note that the red charging indicator on the charger is ON when the M-175 is plugged into the charger through the audio output jack.4. When using the NBC 9-2C charger allow the battery to charge for 14 hours for a full charge. Unit must then be unplugged. When using the NBC 9-3-1 digital fast charger the charger will automatically end the charge cycle and the red LED will change to green. With this charger the unit may be left in the charger until the unit is used.5. Periodically open the battery compartment on stored COMTEK units to check for battery leakage. If a battery is leaking, it must be discarded, and the battery compartment must be cleaned or returned to COMTEK’s service department for repairs.IMPORTANTNBC 9-2C14-hour charger NBC 9-3-1digital fast charger
Page 6M-175 AUXILIARY AUDIO INPUT OPERATIONAuxiliary Audio Input OperationThe M-175 transmitter may transmit a variety of audio sources such as tapeand C.D. players, TV and VCR’s, or any audio device having an auxiliary orline level audio output.The auxiliary input cable supplied with the M-175transmitter (CB-36 ST) will operate with any devicehaving a mini 3.5 mm jack, stereo or mono, andwith line level or earphone level output.To accommodate a variety of specialtyapplications, auxiliary input cableswith RCA phono plug, 1/4” audiophone plug, and XLR connectors areavailable from COMTEK.Setupa. Connect the microphoneto the transmitter byinserting the microphoneplug into the receptacle onthe top of the transmitter.Note: The microphonecord functions as part of thetransmitter’s antenna systemand must be in place for auxiliaryaudio input operation. If microphonefunction is not necessary, the optional microphoneswitch should not be on for this operation.b. Connect the proper auxiliary input cable to the audio source. Connect theright-angle mini plug end of the auxiliary input cable in the “AUX” inputjack of the M-175 transmitter.Note: Check to ensure that the audio source is a line level, earphone level,or fixed AUX level output.
Page 7Belt clip installationM-175 SNAP-ON BELT CLIP (Included)Belt clip removalc. Turn on the transmitter with program from the audio source being fed tothe transmitter. Observe the audio “voice” level modulation indicator. A fullbright LED indicates full audio compression at 100% modulation. For bestperformance, the audio input gain should be adjusted for some low levelLED luminescence during normal audio levels with occasional full brightpeaks indicating 100% modulation.d. When using the auxiliary audio input with the microphone plugged intothe transmitter, priority should be given to the microphone gain adjustment.The mixing balance between the auxiliary audio and the microphone shouldbe made with the volume control of the auxiliary audio source.Note: The optional microphone switch only affects the microphone. It does not affect the auxiliary audio input.M-175 AUX OPERATION (Cont.) / SNAP-ON BELT CLIPSTEP 1:Hook belt clipretaining lip overfront case ridge.STEP 2:Rotate belt clip down onto case. Applypressure on both sides of clip, snappingclip retainers into slots.Clip retainerRetainer slot Belt clip removal indentFlex out and pull down with yourthumb or a large coin (quarter) tounsnap belt clip from case.
Page 8Frequency Selection (72-76 MHz)The M-175 transmitter can operate on one of 88 available channelsbetween 72-76 MHz. COMTEK channel designations indicate a specificfrequency which can be used in the companded or non-compandedmode of operation. When the “compand auto/off switch” is in the “auto”position, the M-175 transmitter must be used only with receivers having 2:1audio companding processing. When the “compand Auto/Off switch”is in the “off” position, standard non-companded receivers mustbe used.After you have determined the channel on whichyou are going to operate, position the two rotaryswitches to indicate the channel. The left rotaryswitch is for tens and the right rotary switch is forones. To select channel 41 (72.92 MHz), positionthe left rotary switch to point to 4 (X10), andposition the right rotary switch to point to 1 (X1).Refer to frequency charts on pages 9 and 10 for selectable frequencies.Multiple Channel OperationWhen multiple transmitters are broadcasting in the same immediate area(within 100 feet), the RF signals will “mix” together generating additionalsignals. If these product frequencies are too close to a frequency which you areusing, you will experience intermodulation interference. This condition iscommon to all radio receivers to some extent.Simultaneous operation of more than three channels requires frequencycoordination to avoid intermodulation interference which could result inpoor or unusable performance.To avoid this type of interference, you should select frequencies from one ofthe standard groups (see group frequency charts on pages 9 and 10), or useCOMTEK’s frequency selection software available at www.comtek.com todetermine appropriate frequencies or contact COMTEK to obtain a free copy.M-175 FREQUENCY SELECTIONCompand Switch
Page 9M-175 FREQUENCY INFORMATIONGROUP 1GROUP 2GROUP 3CHAN FREQ72.02 MHz72.22 MHz72.72 MHz74.61 MHz75.62 MHz75.72 MHz011131457075CHAN FREQ72.08 MHz72.18 MHz72.72 MHz74.77 MHz75.58 MHz75.92 MHz040931536985CHAN FREQ13255457818772.26 MHz72.58 MHz74.79 MHz75.25 MHz75.84 MHz75.96 MHzTransmitter Proximities For MultipleChannel OperationFrequency groups being transmitted shouldbe separated by 2X the operating area;and for best performance, the groupoperating areas should have a 100 ft.minimum separation.transmittersGroup 2operating areatransmitterstransmittersGroup 1operating areaGroup 3operating areaTransmitterseparationTransmitterseparation72-76 MHzSTANDARDCOMPANDED CHANNELSCHAN FREQ72.02 MHz72.04 MHz72.06 MHz72.08 MHz72.10 MHz72.12 MHz72.14 MHz72.16 MHz72.18 MHz72.20 MHz72.22 MHz72.24 MHz72.26 MHz72.28 MHz72.30 MHz72.32 MHz72.34 MHz72.36 MHz72.38 MHz72.40 MHz72.42 MHz72.46 MHz72.50 MHz72.54 MHz72.58 MHz72.62 MHz72.64 MHz72.66 MHz72.68 MHz72.70 MHz72.72 MHz72.74 MHz72.76 MHz72.78 MHz01020304050607080910111213141516171819202122232425262728293031323334CHAN FREQ72.80 MHz72.82 MHz72.84 MHz72.86 MHz72.88 MHz72.90 MHz72.92 MHz72.94 MHz72.96 MHz72.98 MHz74.61 MHz74.63 MHz74.65 MHz74.67 MHz74.69 MHz74.71 MHz74.73 MHz74.75 MHz74.77 MHz74.79 MHz75.21 MHz75.23 MHz75.25 MHz75.27 MHz75.29 MHz75.31 MHz75.33 MHz75.35 MHz75.37 MHz75.39 MHz75.42MHz75.46 MHz75.50 MHz75.54 MHz35363738394041424344454647484950515253545556575859606162636465666768CHAN FREQ75.58 MHz75.62 MHz75.64 MHz75.66 MHz75.68 MHz75.70 MHz75.72 MHz75.74 MHz75.76 MHz75.78 MHz75.80 MHz75.82 MHz75.84 MHz75.86 MHz75.88 MHz75.90 MHz75.92 MHz75.94 MHz75.96 MHz75.98 MHz6970717273747576777879808182838485868788Recommended Channels ForNon-Companded ReceiversCHAN FREQENCY CHAN0515233040677484506072.1 MHz72.3 MHz72.5 MHz72.7 MHz72.9 MHz75.5 MHz75.7 MHz75.9 MHz74.7 MHz75.3 MHzABCDEFGHIJ
Page 10Optional Accessories1. NBC 9-2C Battery charger2. NBC 9-3-1 Digital fast charger3. NBC 9-3-12 Digital 12-station fast charger4. NH9-200 Rechargeable batteries5. BC-216 Snap-on belt clip(supplied with M-175)6. P1 Universal pouch7. SM-185 Unidirectionalelectret condensermicrophone8. PSC-HM Headwornunidirectional electretmicrophoneAuxiliary Audio Input Cords9. CB-36 STM Stereo mini 3.5mm(supplied with M-175)10. CB-36 RCA Phono plug(optional)11. CB-36 ST1/4 Stereo 1/4”(optional)12. CB-36 XLR XLR-F 3 pin connector(optional)M-175 OPTIONAL ACCESSORIES
Page 11M-175 SPECIFICATIONSAudio Input:• Microphone input impedance for electret type microphone - 3000 ohm• Aux/Line input impedance - 10 k ohm (0 dBV nominal)Connectors:Microphone - Micro-mini mono 2.5mmAuxiliary - TRS 3.5mm jackAudio: Tip and sleeveBattery Charging: Tip and sleeveControls and Indicators:• Synthesized channel selection switches• Power On/Off switch• Optional microphone switch• Audio input gain control• Power/Battery status indicator• Audio (voice level) modulation indicator• Manual compand switchFrequency Response:100 Hz to 10 kHzAudio Distortion:Less than 1% at 50% modulationModulation Limiter:Soft compressor with 30 dB linear overloadprotection; attack time - less than 1 ms,recovery time - 10 msFrequency Modulation:7.5 kHz deviation (companded)5.0 kHz deviation (non-companded)Operating Radio Frequency:ity: 88 synthesized channels in the 72-76 MHz band.Out-of-Band Emissions:Better than 50 dB below carrierR.F. Stability:20 ppm XTL controlledDigitally synthesizedRF Power Output:40 mW to antenna systemFCC Compliance:Type Accepted under FCC Part 90Antenna System:Body induction microphone cordantenna.Current Drain:29 mA constant currentBattery:• 9 volt alkaline Eveready 522 or equivalent for up to 16 hours of use• Rechargeable 9 volt Ni-MH 200 mAh battery for up to 5 hours of operation• Rechargeable 9 volt Lithium Polymer 500 mAh battery for up to 16 hours of useDimensions:1 1/16" x 2 1/4" x 3 1/2"(27 mm x 57 mm x 89 mm)Weight:5 ounces (140 grams)NOTE: Specifications subject to change without notice or obligation
Page 12M-175 WARRANTY AND SERVICEWarrantyCOMTEK warrants this product to be free from defects in workmanship andmaterial under normal use and conditions for a period of one year from dateof original purchase. Items such as batteries, neckloops, and cords are notcovered by the warranty. Damage due to misuse, ill treatment andunauthorized modification and repairs are not covered by this warranty. COMTEK isnot liable for consequential damages arising out of any failureof the equipment to perform as intended. COMTEK shall bear no responsibility orobligation with respect to the manner of use of any equipment sold by it.COMTEK SPECIFICALLY DISCLAIMS AND NEGATES ANY WARRANTY OFMERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSEOF SUCH EQUIPMENT INCLUDING, WITHOUT LIMITATION, ANYWARRANTY THAT THE USE OF SUCH EQUIPMENT FOR ANY PURPOSEWILL COMPLY WITH APPLICABLE LAWS AND REGULATIONS.Service PoliciesWarranty repairs must be done by COMTEK. Only factory technicians areauthorized to perform warranty service on the M-175 transmitter. Beforereturning the M-175 for service, a Return Authorization Number shouldbe obtained from the service department by calling 1-800-496-3463 or1-801-466-3463. Return the unit to the factory with the original or comparable packing.COMTEK will pay for insurance and ground return shipping costs in the United Statesfor all warranty service.

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