Instruction Manual
Contents
1. Test Tone switch on the front panel of the MMTS20 to the ON position 3 Adjust the Audio Level control on the front panel of the connected A V modulator for a setting that nulls the aural carrier If more than one null is found use the lowest audio gain setting that produces a null of the aural carrier PILOT LOCK ON H Test OFF TONE DRAKE 2 Using the connected spectrum analyzer tune MODULATOR the aural carrier to the center of the screen Z Spectrum Analyzer Settings lt aypio TAR IMI SPAN 100 kHz AGAUANAVOIACIAU AOA Res BW 1 kHz ViDEO PAL ETAS TY H SWEEP 300 mSec S I UB VBW 1 kHz Aural Carrier Null LAN ATA IAN A NIA A MERVAN Uh N WAA U V WY Aural Carrier Centered2. 8 WARRANTY AND SPECIFICATIONS THREE YEAR LIMITED WARRANTY R L DRAKE COMPANY warrants to the original purchaser this product shall be free from defects in material or workmanship for three 3 years from the date of original purchase During the warranty period the R L DRAKE COMPANY or an authorized Drake service facility will provide free of charge both parts and labor necessary to correct defects in material and workmanship At its option R L DRAKE COMPANY may replace a defective unit To obtain such warranty service the original purchaser must 1 Retain invoice or original proof of purchase to establish the start of the warranty period 2 Notify the R L DRAKE COMPANY or the nearest authorized service facility as soon as possible after discovery of a possible defect of a the model and serial number b the identity of the seller and the approximate date of purchase and c A detailed description of the problem including details on the electrical connection to associated equipment and the list of such equipment 3 Deliver the product to the R L DRAKE COMPANY or the nearest authorized service facility or ship the same in its original container or equivalent fully insured and shipping charges prepaid Correct maintenance repair and use are necessary to obtain proper performance from this product Therefore carefully read the Instruction Manual This warranty does not apply to any defect that R L DRAKE COMPANY determi
3. EREO Loop Through ENCODER O POWER o pier Composite LOCK Audio Out ON Ei test orr _ TONE DC Input og e _ AUDIO LEVEL Audio In MMTS20 FRONT Left audio source 250 mV rms to 2 5 V rms MMTS20 REAR Right audio source The system audio levels are now properly set Disconnect the test equipment 3 Connect the audio source signal not a tone to either the LEFT or the RIGHT Audio Input of the MMTS20 4 Set the Audio LEVEL control on the MMTS20 to a point where the OVERMODULATION indicator just remains off or flashes occasionally 5 While monitoring the opposite audio channel from the TV receiver audio output set the Audio level control on the A V modulator for a maximum stereo separation condition Video Input Audio Input m To System Distribu tion _ 0 or A V MODULATOR V Receiver REAR PANEL CONNECTIONS INTERNAL JUMPERS 3 Figure 2 R1 VIDEO INPUT Connector This is the baseband video input to the MMTS20 which provides the encoder circuitry with the modulator horizontal sync information The baseband video to the modulator must be looped through this input using an external F type Tee T connector R2 COMPOSITE AUDIO OUT Connector This is the unbalanced composite BTSC format stereo signal output The output from this RCA phono receptacle must be connected to the AUDIO INPUT of the modulator The connected modulator au
4. Greater than 65 dB Within 1 dB from 40 Hz to 12 5 kHz 50 dBc typical System performance is dependant upon paired modulator 10 396 kHz 50 Hz 0 5 Vp p 10 all output levels are calibrated to the level of this tone and is used to set system audio levels for proper stereo operation The paired A V modulator audio response must be set for Flat pre emphasis defeated 12 V 5 150 mA 5 V is not required for this unit 0 C to 50 C ambient 1 W x 3 5 H x 7 5 D 2 5 cm W x 8 9 cm H x 19 1 cm D 10 7 oz 0 3 Kg Specifications subject to change without notice or obligation 2 INSTALLATION AUDIO LEVEL SETTING continued 4 Set the MMTS20 TEST TONE switch to the OFF position Connect Left and Right audio source signals to the MMTS20 5 Set the Audio LEVEL control on the MMTS20 to a point where the OVERMODULATION indicator just remains off or flashes occasionally METHOD 2 If a spectrum analyzer is not available 1 Connect the MMTS20 A V modulator compatible DC power source and video source signal as shown on this page Keep the TEST TONE switch OFF for this procedure 2 Connect a TV receiver with MTS stereo capability to the A V modulator Tune the TV receiver to the same channel as the modulator output NOTE Make certain that the audio response of the A V modulator is set for FLAT pre emphasis defeated Video Source MMTS20 Video Input ST
5. RAKE DRAKE DRAKE DRAKE DRAKE SRARE mae POWER SUPPLY G Bad Dod Dad Diod Dad Dod Zad Zad Z EE Ona Yy Ooo Sad Cool Dad rec reco re Cad G E Oaol Cres antes Om Om Om Om Om Om Om Or Orm an Qa Orl On On Br Oar Bw Orm Orv 20 20 20 28 28 28 2 28 Be we v 28 S RE RF RE S RE RF RF S RFE RFE S ne 20 RF o _ AAGAGAAaaAaaAa 2D 4 C MMTS20 and other compatible modular units The R L Drake MMTS20 is an MTS stereo encoder which accepts left and right channel audio input and generates a composite BTSC format stereo signal The composite signal is applied to the audio input of a compatible audio video modulator The modular design of the MMTS20 permits convenient pairing with a Drake Mini rack fixed channel or agile type Video Modulator in a multiple unit rack configuration Rear panel left and right audio inputs allow either balanced or unbalanced operation The MMTS20 must be supplied with the modulator video in order to provide the MMTS20 with sync information for the encoding process A front panel Audio Level control with corresponding Overmodulation indicator permits setting the proper audio input levels to the MMTS20 A Pilot Lock indicator is provided to verify that the encoder is properly synchronized to the supplied video horizontal sync A built in audio test tone genera
6. dio response must be set for Flat pre emphasis defeated R3 DC INPUT Connector This 3 pin connector Male accepts the appropriate mating DC power cable Observe proper orientation and wiring R4 LEFT AUDIO INPUT RIGHT AUDIO INPUT Connectors These are the left and right audio source input connectors that accept either a balanced or unbalanced configuration Use the Tip and Ring of a mating male 3 5 mm stereo plug for a balanced connection If an unbalanced input is required the Ring contact should be connected to ground shield with the audio hot connected to the Tip 4 INSTALLATION CONNECTIONS AND CONTROLS All connections to and from each modulator are made through the rear panel Figure 3 illustrates an installation with 11 modulator units combined through a passive signal combiner Additional channels can be added by using additional fixed channel or agile type modulators and either multi port combiners or combinations of two port combiners maintain a 1 dB variation of adjacent channel carriers Aural Visual A V ratios should be held to 15 dB or less The output RF and A V Ratio controls are used respectively to make these adjustments RACK MOUNTING Adequate ventilation is very important in multichannel installations Some air movement is mandatory in enclosed rack cabinets Excessive heat will shorten component life and modulator performance will be degraded without p
7. nes is due to 1 Improper maintenance or repair including the installation of parts or accessories that do not conform to the quality and specifications of the original parts 2 Misuse abuse neglect or improper installation 3 Accidental or intentional damage All implied warranties if any including warranties of merchantability and fitness for a particular purpose terminate three 3 years from the date of the original purchase The foregoing constitutes R L DRAKE COMPANY S entire obligation with respect to this product and the original purchaser shall have no other remedy and no claim for incidental or consequential damages losses or expenses Some states do not allow limitations on how long an implied warranty lasts or do not allow the exclusions or limitation of incidental or consequential damages so the above limitation and exclusion may not apply to you This warranty gives you specific legal rights and you may also have other rights which vary from state to state This warranty shall be construed under the laws of Ohio DRAKE R L DRAKE COMPANY 230 INDUSTRIAL DRIVE FRANKLIN OHIO 45005 U S A CUSTOMER SERVICE AND PARTS TELEPHONE 1 937 746 6990 TELEFAX 1 937 743 4576 WORLD WIDE WEB SITE http www rldrake com DRAKE MMTS20 STEREO ENCODER 1 12 POSITION RACK UNIT POWER SUPPLY a 4 POSITION OR RACK UNIT D DRAKE DRAKE DRAKE DRAKE D
8. on F4 OVERMODULATION Indicator Lights to indicate greater than 25 kHz of main channel deviation After system audio modulation levels are properly set and with left and right audio source input adjust the AUDIO LEVEL control see item F5 to a point where the OVERMODULATION indicator just remains off F5 AUDIO LEVEL Control The setting of this screwdriver adjustment determines the audio input signal level After system audio modulation levels are properly set and with left and right audio signals within the 250 mVrms to 2 5 V rms range set this control to a point where the OVERMODULATION indicator just remains off see item F4 SPECIFICATIONS 7 AUDIO INPUT Input Impedance Input Level VIDEO INPUT Input Impedance Input Level Range COMPOSITE OUTPUT Output Impedance Output Level STEREO PERFORMANCE Stereo Separation Total Harmonic Distortion S N Ratio Frequency Response Spurious Subcarrier NOTE TEST TONE Frequency Amplitude GENERAL DC Power Input Operating Temperature Range Size Weight 40 K Ohms balanced 20 K Ohms unbalanced 250 mVrms to 2 5 V front panel adjustment High impedance intended to be paralleled with paired A V modulator unit Input Level Range 0 5 Vp p to 2 Vp p 100 Ohms intended to drive high impedance audio input of paired A V modulator 10 mV kHz 10 1 1 Vp p for a 100 modulation signal Greater than 20 dB Less than 25
9. roper cooling INSTALLATION NOTES Level adjustment provides optimum performance in multichannel installations The modulator outputs should be checked periodically with a spectrum analyzer to m VIDEO INPUT _ To Video Input of Video Modulator MMTS20 7 MODULATOR UNIT AUDIO IN STEREO To Video Input Fixed channel and or Agile type RIGHT LEFT ENCODER of MMTS20 audio response set for Flat on gt if AC POWER DC POWER CORD CABLE RF COMBINER SYSTEM OUT Figure 3 INSTALLATION AUDIO LEVEL SETTINGS 5 METHOD 1 Connect the MMTS20 Audio Video Modulator Make certain that the audio response of the A V compatible DC power source video source modulator is set for FLAT pre emphasis signal and test equipment as shown defeated Video Source 00000 HoOgQOE ooogog OO0000 OoOocdO Video Input ie Loop Through 2006 Composite Audio Out SPECTRUM ANALYZER DC Input Left Audio In Coaxial Cable Ca Right Audio In T MMTS20 A V REAR PANEL MODULATOR 1 Set the
10. tor turned on or off from a front panel switch is provided for calibration of the modulator Audio Input level As previously described front panel controls include Audio Level and Test Tone switch Front panel indicators are Power Pilot Lock and Overmodulation A rear panel F type connec tor is provided for the video sync reference Left and right audio inputs are through rear panel 3 5 mm stereo type receptacles The composite BTSC signal output is through a rear panel RCA type phono connector The unit is powered by a compatible Drake Mini rack power supply module DRAKE is a registered trademark of the R L Drake Company Copyright 2001 R L Drake Company P N 3852478D 10 2001 Printed in U S A 2 FRONT PANEL CONTROLS and INDICATORS Fi DRAKE IMTS20 F2 F3 F4 o F5 TEREO ICODER 7222 7 orr _ TONE AUDIO LEVEL De POWER PILOT LOCK TEST OVER OD Figure 1 F1 POWER Indicator Lights when the unit is connected to the required source of DC power F2 PILOT LOCK Indicator Lights to indicate that a video signal is applied to the rear panel VIDEO INPUT connector and that the MMTS20 is locked to the video horizontal sync F3 TEST TONE Switch Switch to the ON position to enable an internal test tone to aid system audio level setup See the Installation section of this manual for setup information The normal position of this switch is the OFF positi
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