Universal Audio BL-40 Operating Instructions Manual Download Page 1 | Manualshive

Page: 1 / 34

background image

www.SteamPoweredRadio.Com

1
2
3
...
»

Summary of Contents for BL-40

Page 1: ...www SteamPoweredRadio Com model BL 40 MODULIMITER products of UNITED RECORO ING ElECTRONICS INDUSTRIES 8460 SAN FERNANDO RD SUN VALLEY CALIFQ RNIA 91352 TELEX 65 1389 UREI SNVY 213 767 1000 QJ Ecompany ...

Page 2: ...www SteamPoweredRadio Com WARNING To reduce the risk of fire or electric shock do not expose this appliance to rain or moisture l l l J 1 I I I I I I I I I I I I I I ...

Page 3: ... COMPLETE UNPACKING AND SETUP CONSULT UNPACKING AND INSPECTION INSTRUCTIONS ON PAGE 4 model BL 40 MODULIMITER United Recording Electronics Industries B460 SAN FERNANDO ROAD SUN VALLEY CALIFORNIA 91352 213 767 1000 Printed in U S A Copyright 1979 UREI ...

Page 4: ...ON 4 1 INPUT ATTENUATOR INPUT AMPLIFIER CIRCUIT 4 2 PHASE OPTIMI ZER 4 3 PEAK LIMITING CIRCUIT 4 4 OUTPUT AMPLIFIER 4 5 POWER SUPPLY SECTION V MAINTENANCE 5 1 GENERAL 5 2 REPAIRS AND WARRANTY 5 3 0 INTERNAL SERVICE ADJUSTMENTS 5 3 l INITIAL SETTINGS 5 3 2 POWER SUPPLY 5 3 3 ZERO ADJUSTMENT OF METERS 5 3 4 Q BIAS ADJUSTMENT 5 3 5 PEAK LIMITING METER TRACKING 5 3 6 PEAK BALANCE ADJUSTMENT 5 3 7 POSI...

Page 5: ...TRANSFORMERLESS OUTPUT CONNECTION ADJUSTING RELEASE TIME OF PEAK LIMITER RECALIBRATION OF OUTPUT METERING ADJUSTMENT OF PHASE OPTIMIZER SENSITIVITY DEFEATING THE PHASE OPTIMIZER TROUBLESHOOTING SIGNAL PATH GENERAL POWER SUPPLY INPUT AMPLIFIER RMS LIMITER PHASE OPTIMIZER PEAK LIMITER THRESHOLD AMPLIFIER OUTPUT AMPLIFIER 5 8 RECOMMENDED SPARE PARTS PARTS LIST SECTION VI ILLUSTRATIONS i i Page 17 17 ...

Page 6: ...usive smooth true RMS limiting U S Patent 3 258 707 It controls the signal level by measuring m1s content and adjusting the gain to produce a constant power output Additional signal condit i oning is achieved t hrough FET peak 1 irlli ting which tightly controls the peak peak amplitude Th is assure s absolute protection from unwanted overmodulation with no peak clipping Attack and release times of...

Page 7: ...former isolated Designed to work into 600 ohm load Output transformer isolated 600 ohms unbalanced 10 dB below rnain output 30 dBm to 25 dBm for SdB limiting 27 dBm 10 dB below output level 70 dB with all controls at maximum 0 0 8 dB from 30 Hz to 15 kHz DISTORTION Less than 0 5 THD 30 Hz to 15 kHz at 24 dBm output SIGNAL TO NOISE RATIO ATTACK TIME RMS SECTION PEAK SECTION RELEASE TIME RMS SECTION...

Page 8: ...ted 150 feet from 50 kW array PHYSICAL FI NISH Clear anodized brushed aluminum front panel Cadmium plated steel chassis DIMENSIONS 19 x 3 1 2 rack panel Depth behind panel 8 483 x 89 x 203 mm WEIGHT Net 11 pounds 5 0 kg Shipping 16 pounds 7 25 kg NOTE Unless otherwise noted in this manual 0 dB is referenced to 0 775 volts RMS 1 3 CONTROLS All crit ical adjust ments are located behind a removable s...

Page 9: ...lip and purchase order to verify th i s option 2 2 ENVIRONMENTAL CONSIDERATIONS The system will operate satisfactorily over a range of ambient I temperatures from 0 C to 50 C 32 F to 122 F nd up to 80 relative humidity I f the system is installed in an equipment rack together with high heat producing equipment such as power amplifiers adequate ventilation should be provided to prolong the life of ...

Page 10: ... Unless a tag on the li ne cord specifies otherwise the Model BL 40 was shipped ready for operation with nominal 115 VAC power mains In order to change this for nominal 230 V 50 or 60 Hz slide the VOLTAGE SELECTOR switch on the rear panel to the 230 position The voltage is visible in a window next to the switch slot Be sure to change the fuse to the correct value 1 8 amp slo blo when changing to 2...

Page 11: ...ED OUTPUT CIRCUITS INPUT GRD OUTPUT COM COM MONITOR FIGURE 3 CONNECTING THE MODEL BL 40 WITH UNBALANCED INPUT AND UNBALANCED OUTPUT CIRCUITS With a balanced input and unbalanced output or vice versa use the appropriate connections suggested by each of the above diagrams No special switching or transformers are needed 6 I ...

Page 12: ...OL SETTINGS The main operating controls are located behind a removable security cover to the right of the meters Before applying power to the unit all controls should be set counterclockwise except the RMS and Peak Zero meter controls which have been set at the factory I 3 3 METER CALIBRATION With no signal applied turn the power ON and check the readings on the RMS and peak meters If necessary ad...

Page 13: ...ram material Should it be desired to increase or decrease sensitivity or to completely defeat the operation of this circuit see Section V Maintenance Field Modification paragraphs 5 6 5 and 5 6 6 3 8 PROOF OF PERFORMANCE TESTS For proof of performance testing the BL 40 should be left in the Limit mode to avoid bypassing circuitry within the limiter Controls may be left set as in normal limiting op...

Page 14: ... in contact with t he light dependent resistors LDR s in the opt ic a l a ttenuato r As increasing input s ignal tries to increase the output of the gain r eduction amplifier made up o f IC 2 Q2 and I Q3 the increased light level results in reduction of the resistanc e of the light dependent resistors This causes increased voltage div i sion at the input of fo llower IC 3 and effectively regulates...

Page 15: ...et to trip at 4 dB peak imbalance This setting is a good compromise between adequate sensitivity and unwanted hunting The voltage controlled phase inverter consists of Ql6 IC 10 I and associated components In the non ineverting green state Ql6 is off because the output of IC 12 is low Under this circum stance IC 10 functions as a unity gain follower and its output is in phase with its input If neg...

Page 16: ... values of these components are chosen so that if the peak signal amplitude exceeds 2 5 volts at the output of either IC 5 or IC 6 the transitor Q5 will be driven out of conduction producing a positive going voltage pulse at its collector The gain of Q5 is quite high and a rela tively large pulse will be produced with a very slight increase in signal above 2 5 volts peak The point at which Q5 begi...

Page 17: ...ntrolled undo the peak limiting of low frequency signals and allow overmodulation The output transformer is designed to be terminated with 600 ohms A resitor should be added across the output to load the BL 40 properly if the transmitter has an input impedance greater than 600 ohms If the input i mpedance of the modulator is less than 600 ohms build out resistors should be added or a step down tra...

Page 18: ...ctory for a Return Authorization Number which must accompany all repairs For prompt service ship the unit prepaid directly to the factory with the RA Number visible on the shipping label Be sure it is well packed in a sturdy carton with shock absorbing material such as foam rubber styrofoam pellets or bubble pack completely filling the remaining space Particular attention should be paid to protect...

Page 19: ...hould go ON in the green state I he suppl y voltage should be 18 volts and be within 10 5 3 3 ZERO ADJUSTMENT OF METERS With no input signal applied adjust a RMS Zero Rl2 until RMS meter reads 0 dB b Peak Zero R66 until peak limit ing meter reads O dB 5 3 4 Q BIAS ADJUSTMElJT Remove IC 5 I C 6 and T4C note that the color mark ing on the IC s have nothing to do with being positive or negative ampli...

Page 20: ...r c Repeat a and b until both Zero and Tracking are sat isfactory 5 3 6 PEAK BALANCE ADJUSTMENT Replace IC 5 and IC 6 Apply a 40 dB 1 kHz signal to the input and turn the Input control clockwise until approximately 3 dB peak limiting is indicated Connect a scope probe to the junction of R40 and CR19 and adjust the Peak Balance with R33 until all peaks are of equal amplitude at twice input frequenc...

Page 21: ...y a 10 dB 1 kHz input signal and turn the Input control clock wise until the Peak meter indicates 1 dB Set the Output control to obtain a convenient output reference level Increase the input signal by 10 dB the Peak meter should indicate 10 dB 1 dB Increase the input level another 10 dB and check to see that the output signal remains within l dB of the reference level compression ratio 20 1 Reduce...

Page 22: ...tortion with RMS and Peak limiting advance the Input control clockwise until 6 dB of fil1S limiting is indicated Adjust the Lirniting control clockwise until Peak limiting indicates 3 dB Set the Output control for 24 dBm and measure the distortion at 50 Hz and 15 kHz The reading must be less than 3 5 5 4 THRESHOLD OF LIMITING Set the Input control clockwise and apply a 1 kHz input signal sufficien...

Page 23: ...d resulting in higher average modu lation The l uF capacitor C35 may be reduced in value to 0 22 uF minimum to decrease both attack and release times This will result in some audible distortion particularly on solo instrument passages 5 6 4 RECALI BRATION OF OUTPUT METERING Some transmitters will require more than 16 dBm to achieve 100 modulation In this case the Output meter se sit i vity may be ...

Page 24: ...to the input set the level of the generator to around 40 dBm and the frequency to l kHz Using a scope probe simply trace through the electronics until the point is found where the signal disappears The signal path is described in some subsequent sections 5 7 2 POWER SUPPLY The most probable power supply fault would be failure of a regulator If spare IC s are available try substitution while monito...

Page 25: ...be 10 1 20 dB 5 7 5 PHASE OPTIMIZER This circuit consists of three major parts a A set of peak rectifiers and storage capacitors b A voltage comparator and switch c The voltage actuated phase inverter IC 11 amplifies signal from IC 3 about 20 dB The output of IC 11 drives two half wave rectifiers CR2 and CR3 With a sinusoidal input signal the voltages at the end of C62 and C63 should be equal but ...

Page 26: ...h the output of IC 4 IC 5 is an LM 318 IC 6 an LM 310 The 846 DE or LF 356 type IC will not work properly in IC 5 or IC 6 s sockets 5 7 7 THRESHOLD AMPLIFIER The threshold amplifier can be checked by grounding the emitter of Q5 The collector of Q5 should rise to over 16 volts and the emitter of Q6 should follow If signal passing through the limiter drops at least 30 dB the FET Q4 is OK 5 7 8 OUTPU...

Page 27: ...de l 13 0206 7818 Positive Regulator 1 13 0207 7918 Negative Regulator l 14 0187 100 uF 25 V Elect rolyt ic Cap 1 14 0307 1000 uF 50 V Electrolytic Cap T4C OPTICAL ATTENUATOR Th is plug in assembly is the heart of the RMS limiter sect ion During operation it behaves very much like a vacuum tube i e it is subject to aging The expected lifetime is 3 to 4 years but depends also on the amount of avera...

Page 28: ...l Red Green 1 4 Amp 115 V AC 1 8 Amp 230 V AC T4C Assembly 16 11178 16 11184 16 11148 16 12261 84 6 DE or LF 356 LM 318 A LM 310 A MC 7818 MC 7918 U 2244 MPS U05 MPS USS 86 5117 2 2N5087 86 5037 3 1N914B 1N4003 MV 5491 or equiv 3AG 3AG 10 12273 2 1 2 Modutec VU Meter w Bezel 40 0022 R3 R8 67 Rl 2 6 6 R24 R33 108 R37 R62 R46 R75 600 ohm T Pad 50 K trim f 1at 10 K trim upright 10 K trim flat 100 K t...

Page 29: ...220 R71 620 R20 680 R73 1 5 k R21 22 k R74 22 k R22 4 7k R91 680 R23 68 k R92 15 k R25 100 k R93 2 2 k R26 330 k R94 3 3 k R27 330 R95 Factory Sel ect R28 22 k R96 10 R29 l M R97 10 R30 22 k Rl00 100 k R31 330 Rl0l 10 k R32 l M Rl02 l 00 k R34 470 k Rl03 180 k R35 4 99 k lg 0 MF Rl04 180 k R36 4 99 k l g 0 MF Rl0S 100 k R38 680 Rl06 100 k R39 l k Rl07 l M R40 3 9 k Rl09 10 k R41 39 Rll0 10 k R42 4...

Page 30: ...V Cl5 0 0033 Mylar Cl6 100 25 V Electrolyt ic Cl8 1 0 Mylar Cl9 100 6 V Electrolytic C20 1 0 Mylar C21 10 pF Ceramic C25 180 pF Silver Mica 5 C26 100 pF Ceramic C27 180 pF Silver Mica 5 C28 3 3 pF Ceramic C29 0 01 Mylar C30 0 1 11 C31 0 1 11 C32 0 1 II C33 0 1 II C34 50 25 V Electrolytic C35 1 0 Mylar C36 6 8 35 V Tantalum C37 50 25 V Electrolytic C38 220 pF Ceramic C39 12 pF II C40 50 25 V Electr...

Page 31: ...www SteamPoweredRadio Com 1 2 3 SECTION VI ILLUSTRATIONS Assembly Drawing Main PC Board 11958 Assembly Drawing Phase Optimizer Board 12204 Schematic Diagram Overall 11965 26 I ...

Page 32: ...I I I I I I I I I I I 0 Q BLK QORG B11184 ALLIEO 54 20SI 6 32 X 3 8 FROM BOTTOM LOCK NUT ON TOP RMS METER 0 0 RSD YEL BYPASS S2 I ZIERICK NO 260 ON FAR SIDE WITH ANGLE FACING UP 6_32 x5 16 FROM FAR SIDE LOCK NUT 6 REQUIRED Merna ASSEMBLY 11958 ...

Page 33: ...www SteamPoweredRadio Com ...

Page 34: ...T AVNLA H roR EARLi UNIT 0 CONTACT IJ R C f 13 7M t 500 R 107 IM 1 1 I Rll3 OK 1 I J RO Cl 6 T J v 17 I I l I 1 K I IN UT UO I V IIL 2 20 c 1 0V 5D 60 MZ r AM C 7 i23 l V Pl 118 se rck 20 l Y t rl A S FOR _i10 1z5 W I eu S 3 POW lt ON ftH NPUT VOI TAC f S UtT J 115 c o 10 11 so I I I t7 on sz on l r100 r uo 311 U55 L 1 OuTPUT AMP lflfR 18 i 18 f F BIK I BlK WKr T 122 1 2 RtOlltl 1 T3 IS 11 e MM M ...

Reviews:

No comments

Related manuals for BL-40

Brand: ABB Pages: 86

Brand: Bang & Olufsen Pages: 2

Brand: DBX Bushido Pages: 12

Brand: jablotron Pages: 2

Brand: jablotron Pages: 2

SimMan 3G Trauma

Brand: laerdal Pages: 16

Brand: laerdal Pages: 16

Brand: laerdal Pages: 60

Brand: laerdal Pages: 4

Resusci Anne Simulator

Brand: laerdal Pages: 8

Nursing Baby VitalSim

Brand: laerdal Pages: 15

Brand: Nektar Pages: 12

Brand: XanLite Pages: 4

Brand: ZOLL Pages: 48

Brand: Össur Pages: 98

Flex Foot Cheetah

Brand: Össur Pages: 107

Brand: Össur Pages: 38

Brand: Össur Pages: 39

Brands by name

0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Popular brands

Load more brands