RCA BTS 101A Stereo Generator Manual
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Broadcast Equipment BTS-101A Stereo Generator Ml-561061A IB-8025127 STEAM POWERED RADIO.COM WARNIN G VOLTAGE S THAT ARE DANGERO US TO LIFE ARE INVOLVE D IN THE OPERATIO N OF THIS ELECTRONIC EQUIPME NT. OPERA TING PERSONN EL MUST AT ALL TIMES OBSERVE ALL SAFETY REGULAT IONS. DO NOT CHANGE TUBES OR MAKE ADJUSTM ENTS INSIDE THE EQUIPME NT WITH VOLTAGE S APPLIED. DANGERO US CONDI TIONS MAY EXIST IN CIRCUITS WITH POWER CONTROL S IN THE OFF POSITION DUE TO CHARGE S RETAINED BY CAPACITO RS, ETC. ALWAYS DISCHARG E AND GROUND CIRCUITS PRIOR TO TOUCHING THEM TO AVOID PERSONA L INJURY OR LOSS OF LIFE. EMERG ENCY FIRST AID INSTRU CTIONS similar equip m ent are urged to Personne l engaged in the installation , operation, or maintenanc e of this equipment or all operating personnel to be of ty du the is It p,·actice. and theory in become familiar with the following rules both life. of loss le avoidab prevent thereby and Aid First ergency Em adequate give to prepared RESCUE BREATHIN G is 2. If he is 11ot, ope11 th8 airway by tilting his head backwa1d. 3. If he is still not breathing, begin rescue breathing: You must find out if the person has stopped breathing. If you think he is not breathing, place him flat on his back . Put your ear close to his mouth and look at his chest. If he is breathing , you can feel the a ir on your cheek . You can see hi s chest move up and down. If you do not feel the air or see th e chest move, he is not breathing. Lift up his neck with one hand and push down on his forehead with the other . This opens the a irway. Sometimes doing this wi ll le t the person breathe again by himself. If it does not, begin rescue breathing . Keep his head tilted ba ckward. Pi nch his nose shut. Put your mouth tightly over his mouth. Blow into his mouth once every five seconds. Do Not Stop Resc ue Breath ing Until Help Comes. 1. Find out breathing. if the person LOOSEN CLOTHING - KEEP WARM Do this when the victim is breathing by himself or help is avai labl e. Keep him quiet as poss ibl e and from beco ming c h il led. Otherwise, treat him for shoc k. BURNS SKIN REDDENE D: Apply ice co ld water to burned area to prevent burn from going deeper into skin tissue. Cover area with clean sheet or cloth to keep away ai1. Consult a physician. SKIN BLISTERE D OR FLESH CHARRED : Apply ice co ld water to burned area to prevent burn from going STEAM POWERED RADIO.COM deeper into sk11 1 tissue. Cover area with clean shee t or c loth to keep away air. T reat victim for shock and t ake to ho spita I. EXTENSIV E BURN-SKI N BROKEN: Cover area wi t h clean sheet or cloth to keep away air. T rea t victim for shock and take to hospital. Broadcast Equipment --- sr1•to-at0oc-MO•o •••• Instructions BTS-101A Stereo Generator Ml-561061A Commercial Communications Systems Division/Front and Cooper Streets/Ca mden, New Jer sey , U.S.A. , 08102 PRINTED IN U.S. A . DL 779 M STEAM POWERED RADIO.COM IB-8025127 II SAFETY PRECAUTIONS Thi s equi pment is designed to fully safeguard all personnel from operating n book hazard s. Labels on the equipmen t and caution notices in the instructio hazards. potential these out nt poi clearly so Any module or Printed Wiring Board may have hazardous voltages exposed, ca ution mu st be exercised. care Fo llow the recommen ded procedure s provided in the Instructio n Book for and maintenan ce of the equipmen t. Always replace the protective co ver s after servicing the equipmen t. WARRAN TY ITEMS stated Particular t arts and / or equipmen t covered by warranty are specifical ly of sale. as such in the warran ty or contract given to the customer at the time war T he warranty or co ntract also stipulate s the condition s under which the ranty may be exercised. RCA To obtain a new replaceme nt for suc h warranty items, contact your local Original the (including sales office and please supply Product Identif ication Serial Invoice Numb er, Ml Number, Type Number, Model Number, and and Number Stock (including n entificatio Id rt Pa nt e Replacem Numb er) and if all Descriptio n). Requests for w arran ty replaceme nts may be unduly delayed this informatio n is not suppl ied. EQUIPME NT LOST OR DAMAGE D IN TRANSIT will When delivering the equipmen t to you, the truck driver or carrier's agent spected in (a) have you until present a receipt for your signatu re. Do not si gn it s and the container s for visible signs of damage and (b) counted the container or if shortage a If . papers shipping the on shown amount compa r ed with the on the made be effect that to notation that insist noted, is damage of evidence shipping papers before you sign them. ly for F urther , after receiving the equipm en t, unp ac k it and inspect thorough the notify ly immediate , red scove di is damage concealed damage . If concealed report. inspection an secure and writing, in n notificatio the irming f con carrier, DAYS Th is item should be unpacked and inspected for damage WITHIN 15 ication Commun RCA, to es after receipt. R eport all shortages and damag Systems D ivision - Camden, N ew Jersey 08102. as the RCA will file all claims for loss and damage o n this equipmen t so long be inspection report is obtained. Dispositio n of the damaged item will fu rnished by R CA. FIELD ENGINEE RING SERVICE RCA F ield engineerin g tive or the - Camden, Engineerin g Service is available at current rates. Requ ests for field service may be addressed to your RCA Broad cast Field Repre se ntaRCA Service Company , Incorpora ted - Broad cast Service Divi sion New Jersey 08102. T elephone (609) 338-3434 . TECH ALERT s is Em ergency 24 hour t elerh one consu ltation se rvi ce for t ec hnical problem be for available. Call TECH ALERT at (609) 338-3434 . T elex messages will -4450. warded to the addressee upon recei pt. Western Un io n telex number is 83 STEAM POWERED RADIO.COM III TABLE OF CONTENTS Page TECHNICAL SUMMARY V LIST OF EQUIPMENT VI RECOMMENDED TEST EQUIPMENT VI GENERAL DESCRIPTION INSTALLATION General Mounting the Interconnect Cable Connections to the Main Cable Connector Stereo Generator in other Applications Final Mounting . . . Interface/Radiate Panel Exciter Unit Stereo Generator 7 ROUTINE OPERATION . . . 7 DETAILED CIRCUIT DESCRIPTION 8 FIELD MODIFICATIONS . . . . . Power-u p to Monaural Mono Source Selection Rewiring Power Transformer for 240 V ac Input 2 2 2 5 6 6 7 7 11 11 11 11 ALIGNMENT PROCEDURE . . . Test Equipment Power Supply Check . . Audio Stage Alignment Audio Filter Alignment Separat i on Adjustment Pilot Adjustment . . Remote Functions . . . Final Considerations . 17 17 PARTS ORDERING INFORMATION Replacement Parts Emergency Part Service 18 18 18 REPLACEMEt!T PARTS . . . . 19 SUGGESTED STATION SPARES 24 11 11 12 12 14 14 15 LIST OF ILLUSTRATIONS Figure 1A B 2 3 Title Front Panel Controls and Indicato r s Rear View Stereo Generator Block Diagram Oscilloscope Wavefo rms STEAM POWERED RADIO.COM Page 1 1 3 16 IV LIST OF ILLUSTRATIO NS (Continued ) Title Figure 4 5 6 7 8 9 10 11 12 13 14 15 BTS-101A Top View PW Board Switches and Adjustments Dual Input Pad Components Location BTS-101A Stereo Generator Schematic .udio Lowpass Filter Schematic .A Audio Lowpass Filter Components Location 53 kHz Filter Schematic 53 kHz Filter Components Location BTS-101A Stereo Generator Components Location Interconnecting Cable Schematic Precision Differential Test Generator Schematic De-emphasis Network Schematic STEAM POWERED RADIO.COM Page 25 26 26 27 29 29 30 30 31 33 35 37 V TECHNICAL SUMMARY PERFORMANCE Resistive 600 ohms, Balanced Audio Input Impedance . . . +10 dBm+ 2 dB at 400 Hz . Audio Input Level . . . dB, 30-Hz to 15,000 Hz ~1 Audio Frequency Response 0.5% or less Harmonic Distortio n . . . or less 0.3% n Intermodu lation Distortio 70 dB . . . . . . . Signal to Noise Ratio 1 Hz + kHz 19 . . Pilot Carrier Stability dB 40 . . . . . . . . Separatio n . . . . dB 50 n) to modulatio 100% (referred on Subcarrie r Suppressi Crosstalk 45 dB Without Audio Low Pass Filter . . 40 dB . . . Filter With Audio Low Pass e switchabl usec, 75 or 50 25, 0, Constant Pre-Emphasis Network Time eak peak-to-p volts 3.5 . . . . . Output Level . . . . . . . . 180 ohms Output Impendance (See Note 1) ELECTRICAL 120 or 240 volts, single phase, 50/60 Hz Power Line Requirements . . . . . . . . +10% n Regulatio and Combined Line Voltage Variation watts max. 10 . . . . . . . . . . . . . . . Power Consump tion. . . . . . . MECHANICAL Dimensions, inches (cm) (overall) : Width Height Depth Weight, pounds (kg) . . Altitude, feet (meters) Ambient Temperature . . NOTE 1. .• 19 (48.3) 1. 75 (4.4) 9 (22.9) 7. 125 (3.23) 7500 (2286) max . . -200C to +700C (-40F to +1400F) The BTS-101A will meet all listed performan ce specifica tions with up to 10 feet of RG-58/U cable feeding into a load impedance of 5000 ohms or greater; and will meet all FCC rules in effect as of date of manufactu re with up to 50 feet of RG-58/U cable. STEAM POWERED RADIO.COM VI LIST OF EQUIPMENT BTS-101A Stereo Generator, less two Audio Lowpass Filters Plug-in 15 kflz Lowpass Filters (two) . . . . . . . . . . Complete set of connector plugs for the BTS-101A Stereo Generator (required only when Interface Panel MI-561071 and/or Interconnecting Cable MI-561067 are not used) (optional) Set of chassis slides for servicing (optional) Drilling Template for mounting units (optional) MI-561061A MI-56106LI I I MI-561069 MI-561073 3742738 RECOMMENDED TEST EQUIPMENT Precision AC Voltmeter H.P. 400FL or equivalent Audio Oscillator H.P. 200CD or equivalent Sweep Generator Wavetec #180 or equivalent Precision Differential Amplifier See figure 14. DC Voltmeter Simpson 260 or equivalent De-emphasis Network See figure 15. Oscilloscope Tektronix Type 531 with Type H plug-in or equivalent. Scope requirements are detailed in the Separation Adjustment procedure. Stereo FM Monitor BW-85A (BW-185) fitted with external input attenuator (SK pot connected through a maximum of two (2) feet of RG-58/U to the monitor's baseband input). STEAM POWERED RADIO.COM STEREO CRIOI - --•TOIi MODE SIOI MONO CRl02 SEPARATION LEFT RIOI OUTPUT LEVEL RI03 SEPARATION RIGHT Rl02 IIT8• IOI A FIOI XFIOI INPUTS JIOI COMPOSITE STEREOPHONIC OUTPUT JI02 B IK218 Figure 1. BTS-101A External Views GENERAL DESCRIPTION The BTS-101A is a completely self-contained stereo generator needing no parent Al though designed equipment to generate the composite sterephonic signal. specifically to operate in conjunction with the RCA BTE-115 FM Exciter, the BTS-101A may be used in any application requ1r1ng the generation of a high-quality stereo signal. Since it is self-contained, it may be tested and adjusted without the need of an exciter. A pair of program audio signals, preferably processed by the RCA BA-150 Digital Overshoot Compensation (DOC) Processor, are applied to the input of the unit. (See block diagram, figure 2) . These signals are routed through the rf filter Each channel signal is then preto the internal printed wiring board. filter. The pre-emphasis is lowpass audio kHz 15 a to applied emphasized and adjustable and both the pre-emphasis and the audio lowpass filter are switch defeatable. The two audio channels, thus processed, are applied to the analog inputs of an electronic switch operating at 38 kHz. The 38 kHz switching signal and the 19 kHz pilot tones are both derived from a stable 3.04 MHz crystal oscillator. The output of the electronic switch is applied to a phase-linear The filter lowpass filter to remove unwanted switching-signal components. to the application for peak-to-peak volts 3.5 of level a to amplified is output normal the to addition In Exciter. BTE-115 the normally equipment, following samples, signal audio of pair a delivers BTS-101A the output, signal composite representative of the individual audio channel modulationg signals, for application to the metering system of an affiliated BTE-115 FM Exciter. Remote mode STEAM POWERED RADIO.COM 2 switching connections are located at the rear connector. A momentary closure to ground is needed to switch modes; an internal latch keeps the unit in the selected mode. INSTALLATION GENERAL This procedure covers installation of the BTS-101A Stereo Generator either in other applications or when used with the BTE-115 Exciter in the following RCA transmitters. BTF-3ES1 BTF-5ES2 referred to in text as BTF 3/5 BTF-5ES1 BTF-10ES1 BTF-20ES1 referred to in text as BTF 5/10/20 This procedure can generally be applied to other FM exciters and transmitters as well. Drilling and tapping of the required mounting holes in the cabinet should already have been accomplished in these RCA transmitters (see BTE-115 Exciter Unit Instruction Book IB-8025256-1), and the transmitter should be prepared for exciter installation using the instructions. MOUNTING THE INTERCONNECT CABLE An interconnecting cable assembly, MI-561067-4, -5, or -6 may be supplied with This the exciter system, and may already be installed in the transmitter. cable interconnects the stereo generator to the BTE-115 exciter unit, and also provides for inputs to the system. In the BTF-5/10/20 transmitter (if not already installed), mount the interconnect cable along the inside edge of the front left hand mounting rail in the transmitter, using flat head screws and cable ties provided with the cable as required. The cable should be positioned so the end with the 24 pin connector extends toward the bottom of the transmitter, and such that the two, three, or four legs of the cable will breakout in the area where the associated units Connect the cable to the existing transmitter wiring, and will be mounted. coil any excess length in the bottom of the transmitter. For the BTF-3/5 transmitter, mount the cable as shown in figure 7 of either the BTF-3ES1 (IB-8027593-1) or the BTF-5ES2 (IB-8027984-1) Instruction Book. When the optional chassis slides MI-561073 are used, the same holes are used Refer to instructions for mounting the chassis slides and the cable ties. provided with the chassis slides for installation details. STEAM POWERED RADIO.COM 3/4 METE RI N < SAMPL E I fl BT E - 1 1 t------• L INPUT LEFT PRE EMPHASIS LP F PROGRAM (ACTIVE) TERMINATION IN PUT 0 PRE-EMPHASIS GAi N 0 0 E LECTR ONI< SINUSOIDALIZI G OUTPUT LOW PASS AMPLIFIER AMPLIFIER IN OUT SWIT CH COMPOSITE OUTPUT TO EXCITER. IN PUT RIGHT PROGRAM PRE TERMINATION EMPHASIS STEREO L P F OUTPUT LEVEL GAIN (ACTIVE) • R t--------11 IN PUT l9kHz VECTOR CROSSTALK ADJUSTMENT 0 38 kHz IN OUT 3,04 MHz l9kHz DIVIDER S CLOCK PH A SE PILOT STER 0/ MONO TANK MODE LATCH MODE ~PILOT I FREQUENCY POWER SUPPLY . Pl LOT DIVIDER PHA SING • REMOTE 3K041 l• I 11,1u STEAM POWERED RADIO.COM t ;i. Stereo Generator Bloc k Di agram 5 \ CONNECTIONS TO THE MAIN CABLE CONNECTOR The 24 pin plug on the interconnect cable provides for audio input to and remote control of the exciter system. Connect as follows: 1. BTF-3/5 Transmitter - Install the mating connector supplied with the interconnect cable as item 2. Bring audio input and remote control lines directly to this connector as follows: Circuit Pin Numbers 1 &2 Left Audio Input Shield 3 Right Audio Input 4 &5 Shield 6 Remote Stereo On 16 Remote Mono On 17 Remote Common 18 If SCA Unit is to be used, do not re-assemble connector cover, as additional wires will be added. Operational Note: Momentarily shorting pin 16 to pin 18 causes stereo operation. Momenarily shorting pin 17 to 18 causes monaural operation, using the left input signal as the mono source. 2. BTF-5/10/20 Transmitter - If the transmitter is not equipped with a 24 pin plug to mate with the interconnect cable, use the connector supplied with the interconnect cable as i tern 2. Remove existing connectors from cables Nos. 201 thru 204 and connect these cables to the 24 pin plug as follows: Cable II STEAM POWERED RADIO.COM To Pin If Black Red Shield Circuit 201 1 2 No Connection Left Audio In 202 4 5 No Connection Right Audio In 203 10 11 No Connection SCA 111 Audio In 204 13 14 No Connection SCA 112 Audio In 6 Remove wires number 514, 516, and 517 from the cable harnes s that was removed from the transm itter during the install ation of the BTE-115 excite r. Connect these wires from 1TB6 to the 24 pin connec tor as follows : Wire II From To Pin II 514 1TB6-15 17 Remote Mono On 516 1TB6-17 16 Remote Stereo On 517 1TB6-18 18 Remote Common Circui t If SCA Unit is to be used, do not re-asse mble connec tor cover, as additio nal wires will be added to this connec tor. Operat ional Note: Momentarily shortin g 1TB6-17 to 1TB6-18 causes normal stereo operat ion. Momentarily shortin g 1TB6-15 to 1TB6-18 causes monaural operat ion, using the left input signal as the mono source . STEREO GENERATOR IN OTHER APPLICATIONS For install ations where the stereo genera tor is not mounted adjace nt to the BTE-115 excite r as well as operati on remote from the transm itter, the interconnec t cable will not be utilize d. In this case, a complete set of connec tors for the stereo genera tor may be ordered as MI-561069 and a complete set connec tors for the BTE-115 may be ordered as MI-561068. Item 1 of connec tor of MI-561069, which mates with J101, must be utilize d. Connect audio input kit and mode contro l lines to this connec tor as follow s: Circui t Pin Number Left Audio Input High Left Audio Input Low Shield 6 3 2 Right Audio Input High Right Audio Input Low Shield 4 1 5 Remote Stereo On Remote Mono On Common 10 12 11 Operat ional Note: Momentarily shortin g pin 10 to pin 11 causes stereo tion. Momentarily shortin g pin 12 to pin 11 causes monaural operat ion.operatching may be accomplished by a switch , pushbu tton, relay or NPN transis tor. Swi- FINAL t-OUNTING For system s utilizi ng an SCA genera tor, omit the remainder of this install ation procedu re and go to the install ation instruc tions for that unit. If no SCA is to be used, mount the Exciter System Components as follows: c- STEAM POWERED RADIO.COM . 7 INTERFACE/RADIATE PANEL Mount panel in place and connect the 4 pin plug and ac twist-lock connector to the panel. Dress associated cables to not interfere with removal of the exciter or stereo generator for servicing. EXCITER UNIT Connect the umbilical cord extending from the interface panel to the 6 pin control connector at the rear of the exciter. Connect the 10 pin plug on the interconnect cable to the mating input connector on the exciter. Connect the associated rf connector from the interconnect cable to the composite input on the exciter. (If there are additional rf connectors on this cable, they will be labeled "SCA" an should connect to the SCA INPUT on the exciter). Connect the rf output and ac power cables to the exciter, and mount the exciter in place. STEREO GENERATOR Connect the 12 pin connector on the interconnect cable to the INPUT connector J 101 of the stereo generator, and the associated r f connector to the OUTPUT jack J102. Plug accord into the interface panel. Mount stereo generator. Fill unused space(s) with blank panels. ROUTINE OPERATION Frequent readjustment of the BTS-101A circuitry is not normally necessary. Occasional manual or remote mode switching will be the most common operation. The transmission mode may be switched from stereophonic to monaural (with a preselected audio channel for the source), and back. Switching can be accomplished by a momentary (or continuous) connection to ground, and that connection can be accomplished by a switch, pushbutton, relay or NPN transistor . The selected mode is indicated by the light-emitting diode stereo or mono indicator lamp. Refer to the schematic diagram, figure 7. The stereo pilot should be held at a level of 9%. The most convenient method of trimming this level is the front-panel OUTPUT LEVEL control. This is a vernier adjustment, with a few dB of range. Should the desired setting of this control be at an extreme of its range, resetting the internal PILOT LEVEL control R46 may be called for, or resetting the audio limiter outputs may be in order. See Alignment Procedure. The normal output level from the BTS-101A is 3. 5 volts peak-to-peak for 100% modulation . This should occur with a 10 dBm input level. The SEPARATION control settings should be checked during routine proof of performance checks. Separation tests will require that programming material be removed from the channel under test. STEAM POWERED RADIO.COM 8 DETAILED CIRCUIT DESCRIPTION Left and right audio signals are applied to the INPUTS connector J101 on the rear of the BTS-101A. Refer to the schematic diagram, figure 7. The left channel is connected to pins 3 and 6, while the right channel is connected to pins 1 and 4. Pins 2, 5, 8, and 11 are available to ground the shields of these lines. The audio signals are routed to the printed wiring board through rf filters composed of L101, L102, L103, and L104 operating in conjuncti on with capacitor s C101, C102, C103, and C104. Following the rf filtering , the signals are applied to the input pads and transform ers T102 and T103. The left channel input transform er is terminate d by R5, in parallel with R6, R7, and RS. The range of the LEFT GAIN control R7 is restricte d by R6 and RS. The output from R7 is applied to R9, which, with C1, forms an on-board rf filter. The output of this filter is then amplified by U1. Capacitor C4 is placed in the negative feedback loop of U1 to cause a very slight but predictab le phase lag at 15 kHz. The output of amplifier U1 is fed into a phase correctio n network comprised of R12, R13, and C6, to allow low audio frequency square wave transmiss ion. Capacitor C5 is added to this network to compensat e for a slight high-freq uency loss at 15 kHz in the audio lowpass filters. The signal is then fed to amplifier U2 which functions as an active pre-emph asis network. The pre-emph asis time-cons tant is determine d essential ly by the sum of R15 and R16 operating in conjuncti on with capacitor (s) C12 and C13. A flat frequency response is obtained by switching out both C12 and C13. A 50µs time-cons tant is obtained by switching in C13 only; 75µs is obtined by also switching in C12. In either case, LEFT PRE-EMPIIASIS control R15 is adjusted for the correct frequency response. The output of U2 is applied to the 15 kHz audio lowpass filter FL 1 via series terminati ng resistor R18. The filter output, terminate d by R20 is applied to buffer U3 (to drive the electroni c switch for stereo generatio n) and to U7 (to drive the metering system in the BTE-115 FM Exciter). C14 limits the audio noise bandwidth to 60 kHz when the audio lowpass filter is switched out. The right audio channel functions in a manner similar to the left except that various adjustmen ts have been added to enable precise audio channel phase and amplitude tracking to easily allow linear crosstalk cancellat ion. Specifically, 150 Hz control R28 allows the individua l audio channels to be adjusted to an identical value at low frequenci es. When the pre-emph asis is switched out, 15 kHz (FLAT) control C24 should be adjusted for audio channel phase tracking at 15 kHz. When the pre-empha ses is switched in, 1500 Hz control R37 enables the right pre-emph asis time-cons tant to be trimmed to agree with that obtained in the left channel. Phase agreement at 15 kHz is enabled by 15 kHz control R35. The output of U4 is applied to the 15 kHz audio lowpass filter FL2 for the right channel through series terminati ng resistor R40. Filter output is terminated by R42 and -is applied to buffer U6 ( to drive the electroni c switch for the stereo generatio n process), and to U8 (to provide an audio sample for the affiliate d BTE-115 Exciter metering system). C35 limits the audio noise bandwidth to 60 kHz when the audio lowpass filter is switched out. STEAM POWERED RADIO.COM 9 The outputs of U3 and U6 are applied to the electronic switch U9 through de blocking capacitors C18, C19, C39, and C40. Diodes CR5 and CR6 prevent the blocking capacitors from becoming reverse-biased by power on and power off transients. The transmission of the left signal from pin 3 to pin 2 of the electronic switch is controlled by the switching signal applied to pin 1. A 38 kHz square wave from U15 is applied to this pin, resulting in a left channel signal, switched on and off at a 38 kHz rate, being present at pin 2. Likewise, the right channel signal is transmitted from pin 6 to pin 7, controlled by a 38 kHz square wave applied to pin 8. However, the control signal at pin 8 is 1800 out of phase with the control signal at pin 1. Therefore, pins 2 and 7 can be connected together and the resultant signal at the combined point will switch from left to right at a 38 kHz rate. The output of the electronic switch is applied to summing amplifier U10 through resistors R57 and R58. Capacitor C22 limits the maximum slow rate from the electronic switch to less than 50 volts per microsecond, thereby insuring that transient intermodulation distortion products will not be generated in the summing amplifier. Separationcorrection signals from LEFT SEPARATION control R101 through R59 and RIGHT SEPARATION control R102 through R44 are also applied to the summing amplifier. The pilot signal is derived from a 3.04 MHz crystal oscillator formed by Q1 and associated components. The frequency of this oscillator is determined primarily by crystal Y1. The signal may be trimmed to the desired frequency (corresponding to a pilot-tone frequency of 19.0 kHz) by PILOT FREQUENCY capacitor C54. Transistor Q2 interfaces the oscillator into the logic buffer U12B. The output of U12B at pin 4 is a pulse at a rate of 3.04 MHz and is applied to divider U13 for division down to 304 kHz. The output of U13 at pin 11 is applied to the input of U14, which divides the signal down to 76 kHz. The output of U14 at pin 9 drives the final divider U15. The outputs at U15 pins 5 and 6 are the aforementioned out of phase 38 kHz pulses which drive the electronic switch U9. A 19 kHz signal is also supplied by divider U15 at pin 9. The 19 kHz signal is buffered by U12A and is then applied to buffers Q3 and Q4. The low impedance of this stage provides drive for the pilot filter consisting of L 1 and PILOT PHASE control C58. L 1 permits phasing or timing of the pilot tone relative to the 38 kHz switching signal . The output of PILOT LEVEL control R46, a sinusoid, is applied to the summing amplifier through R45. GAIN of the summing amplifier U10 is determined by STEREO GAIN control R61, The output of this stage is applied to the whose range is limited by R60. phase-linear 53 kHz lowpass filter FL3 through series terminating resistor R63. The filter output is terminated primarily by R64. This filter attenuates any signal component above 53 kHz. This results in a smoothing out of the switched pulse left and right signal into a continuous wave. Signal input to the output buffer amplifier U11 is determined by K1, which selects either the mono input from pin M or the stereo signal appearing across R64. The mono signal source is determined by the connection to pin M of either the left channel (L) input or the right channel (R) input. The unit is normally wired to utilize the left channel signal, but conversion in the field to supply the right channel signal for mono transmission may be easily accomplished. Refer to the FIELD MODIFICATIONS section, Mono Source Selection and to fi gures 5 and 7 . To eliminate the possibility of phase-cancellation problems in the interconnecting link between the program source and the transmitter site, only one audio channel at a time is accepted for transmission in the mono mode. For proper channel balance, both the L and R cables must remain connected to their respective terminals . STEAM POWERED RADIO.COM 10 Relay K1 is controlle d by transisto r Q5. This transisto r is part of a latching circuit involving Q5, Q6, Q7 and Q8. This latch may be switched from one mode to the other by operating either the front panel mode switch or by momentary connectio n to ground of the remote control terminals , J101, pin 10 or 12. A transisto r or open-coll ector TTL gate may be used to accomplis h remote control swi tching. Capacitor C60 simulates closing of S101 to the STEREO position so that the latch will set to the STEREO mode upon each applicati on of power. I f it is desired to power up to monaural operation , move C60 to the equivalen t posi tion near Q7. Installin g C60 in the alternate position is described in the FIELD MODIFICATIONS section, Power Up to Monaural. Light- emitting diodes CR10 1 and CR102 indicate the mode status on the front panel. The power supply is of conventio nal design, with a split-prim ary power transform er, full wave rectifica tion, and electroni c regulatio n of critical voltages. STEAM POWERED RADIO.COM 11 FIELD MODIFICATIONS POWER-UP TO MONAURAL The BTS-101A is normally shipped from the factory wired to return to the stereophonic mode of operation at turn-on or following a power failure. Should it be necessary to return to the monaural mode following a power failure, one capacitor must be moved. Locate C60 (10 MF 20 volts) on the components layout drawing, figure 5, and the BTS-101A top view, figure 4, and carefully de-solder it from the printed wiring board. Reinstall the capacitor in the pair of holes immediately to the left of the original location ( as viewed from the front). The unit will now return to monaural operation following a power failure. This change does not affect the stere-mono switching . MONO SOURCE SELECTION The stereo generator is normally shipped to utilize the left channel for monaural transmission. To select the right channel, unsolder the center conductor of the shielded cable (L) from the terminal immediately in front of the monostereo selection relay K1. In its place, solder the center conductor of the companion (R) shielded cable. NOTE: Both Land R cables must remain in place and connected to terminals L and R for proper channel belance . In case of a modification to right channel mono output, insure that the M pin end of the unused cable does not short. REWIRING POWER TRANSFORMER FOR 240 V AC INPUT The BTS-1 01A is normally wired for a primary voltage of 120 V ac . The splitprimary power transformer, T101, can have its windings connected in series for 240 V ac input, as shown on the schematic. The transformer has been designed for either 50 or 60 Hz operation. When the transformer is reconnected for 240 V ac operation, the fuse should be changed to one with a 1/8-ampere rating. ALIGNMENT PROCEDURE The internal adjustments are factory sealed to prevent changes due to vibration during shipment, and should not normally require field adjustment. This alignment procedure is provided in the event that component replacement or other unusual conditions make realignment necessary . TEST EQUIPMENT The test equipment listed in the RECOMMENDED TEST EQUIPMENT l ist in the front of this book is necessary for the alignment of the BTS-101A Stereo Generator. It is very important that the test equipment be checked periodically for accuracy of calibration . STEAM POWERED RADIO.COM 12 POWER SUPPLY CHECK 1. Apply power to the stereo generator and check the de voltages at TP6 (gray) and TP7 (white). Refer to figure 4. The voltages should be plus and minus 24 volts, _:!:10% respectively. 2. Check the voltage regulators by testing the following points ( see figure 12): A. B. C. The de voltage at U1 pin 7 should be 12 volts +5% . The de voltage at U1 pin 4 should be -12 volts-+5%. The de voltage at U15 pin 14 should be 5 volts +5%. AUDIO STAGE ALIGNMENT 1. Connect the left and right audio inputs in parallel and in phase and apply a 2.45 volt rms audio signal at 2122 Hz (equivalent to an L=R signal of +10 dBm). 2. Check that stereo generator is in STEREO mode (S101 to STEREO), and set the PILOT LEVEL control to off (R46 fully counterclockwise). 3. Set the audio amplifiers flat by switching out pre-emphasis networks (switches S1 through S4 to left) and audio filters out (switches S5 and S6 up). 4. Set LEFT GAIN control (R7) for an output level of O dBV (0 . 775 V rms) at TP3 (green). 5. Set right channel 150 Hz linear crosstalk control (R28) for a O dBV level at TP4 (blue). 6. Reduce oscillator level until output at TP3 equals -3 dBV (0. 548 V rms) . Switch to left channel pre-emphasis networks (switches S1 and S2 to right) and adjust LEFT PRE-EMPHASIS control ( R15) until output at TP3 equals 0 dBV. Switch out left pre-emphasis (switches S1 and S2 to left) and return oscillator to original level. 7. Switch in left channel 15 kHz audio lowpass filter FL 1 (rear filter, switch S5 down). Set oscillator to 19 kHz. While monitoring TP3 with an oscilloscope; A. B. C. D. 8. Adjust inductor L4 for a null. See fig ure 9. Adjust L6 for a null at 22 kHz . Adjust L2 for a null at 30 kl-lz. Recheck 19 and 22 kHz adjustments . Switch left channel filter out of the circuit (switch S5 up). Move the scope to TP4 and switch in the right 15 kHz lowpass filter FL2 (front filter, switch S6 down) . Set the oscillator to 19 kHz and; A. B. Adjust inductor L4 for a null. Adjust L6 for a null at 22 kHz, STEAM POWERED RADIO.COM f 13 C. D. 9. Adjust L2 for a null at 30 kHz. Recheck 19 and 22 kHz adjustments. out of the circuit (switch S6 up). Switch the right 15 kHz filter Disconnect the audio oscillator from the generator inputs and connect a sweep generator in its place. A. Set the scope for external horizontal input and drive this input with the control voltage output of the sweep generator. Set the sweep width of the generator to cover the range of 200 Hz to 16 kHz, and set the sweep rate to approximately 5 sweeps per second. B. This step requires the use of a precision differential amplifier having a common mode rejection ratio of approximately 80 dB. Such an amplifier may be constructed as shown in figure 14. Connect the inputs of the precision unity gain differential amplifier to TP3 and TP4 and connect the differential amplifier output to the vertical input of the oscilloscope. C. Set the scope to 1 V/cm sensitivity; feed a left only reference signal to the sweep generator, and adjust the output level of the sweep generator to yield a 2 volts peak-to-peak signal on the scope. Feed an L=R signal to the stereo generator and set the scope sensitivity to 5 mV/cm. The scope now displays amplitude and phase errors (between the two audio channels) on the vertical axis against frequency on the horizontal axis. Adjustments will now be made which will reduce these errors to 5 mV peak-topeak ( 1 cm peak-to-peak) which is 52 dB below the reference level. It may be necessary to decrease the scope sensitivity at the beginning of an adjustment but the displayed error should ultimately be below 5 mV peak-topeak (1 cm peak-to-peak on 5 mV/cm setting). Confirm that both pre-emphasis networks are switched out through S4 to the left). (switches S1 10 . Adjust right channel 150 Hz linear crosstalk control (R28) for minimum amplitude on the scope during the mid and low-frequency portion of the sweep. Adjust 15 kHz linear crosstalk (FLAT) capacitor C24 for minimum amplitude at the higher frequencies. 11. This step requries that the sweep generator signal be de-emphasized. Insert a suitable de-emphasis network, such as the one shown in figure 15, between the sweep generator and stereo generator. Note that the deemphasis network shown is designed to work into the 300 ohm impedance presented by the parallel connection of the left and right inputs of the stereo generator. Whenever this network is used to feed a single 600 ohm input, that input should be paralleled with a 600 ohm resistor so that the de-emphasis network always operates into a 300 ohm load. Switch in the pre-emphasis networks of both audio channels ( switches S 1 through S4 to the right). Adjust right channel 1500 Hz linear crosstalk control (R37) for minimum amplitude at the mid-frequencies. Adjust right channel 15 kHz linear crosstalk control (R35) for minimum amplitude at the high frequencies . STEAM POWERED RADIO.COM 14 12. Repeat steps 10 and 11 (de-emp hasis and pre-emp hasis out for step 10). AUDIO FILTER ALIGNMENT During this phase of alignme nt, the permiss ible error magnitud e will be relaxed to . 01 volts peak-to- peak (2 cm peak-to- peak on 5 mV/cm setting ), which is 46 dB below the referenc e level. The differe ntial amplifi er, sweep oscilla tor, and oscillos cope should remain in the same configu ration as utilized in the previous steps. Again, it may be necessa ry to vary the scope vertica l sensitiv ity at the beginnin g of this adjustm ent, but the error should utimate ly be .01 volts peak-to- peak, or less, for frequen cies below 15 kHz. 1. Switch in both left and right channel audio lowpass filters (switche s .S5 and S6 down) and carefull y adjust each inducto r slug on FL 1 and FL2 for m1n1mum error. This alignme nt should be accomplished by a number of small systema tic adjustm ents working from inducto r to inducto r in a repetiti ve cycle. No single adjustm ent will obtain the desired results , but rather, a balance of a number of correct adjustm ents is necessa ry. The criterio n for a correct single adjustm ent is to reduce the error single amplitud e as much as possible while simultan eously reducing amplitud e variatio ns (ripple) in the error signal. Both criteria ,;ire equally importa nt and reductio n of error amplitud e at the expense of increasi ng error ripple is to be avoided . When this point is found, it is time to move on to another inductor for further adjusme nt. When the audio filters are properly adjusted , the differentia l amplifie r should yield a moniton ically rising error signal with increasi ng frequenc y. The end result should look trumpet shaped, with the error signal not exceedin g .01 volts peak-to- peak at 15 kHz and below. 2. Switch the left and right channel pre-emp hasis network s out (switche s S1 through S4 to left) and remove sweep de-emph asis. Confirm that the filters meet specific ation in this configu ration. 3. Disconn ect the differe ntial amplifie r and sweep oscilla tor. Re-conn ect the audio oscillat or to the left input at +10 dBm. While monitor ing TP3 with an audio voltmet er, confirm that the frequenc y response is down not more than 0.5 dB at 10 kHz, and not more than 1 dB at 15 kHz. Also, check that the stopband response is down 40 dB or better at and above 19 kHz. 4. Repeat step 3 for right channel at TP4. SEPARATION ADJUSTMENT 1. Insert the de-emph asis network and switch in the stereo generat or's left and right channel pre-emp hasis network s (switche s S1 through S4 to right). 2. Set the front-pa nel SEPARATION LEFT and SEPARATION RIGHT control s of the stereo generato r to mid-pos ition. Also, set the variable capacito r (C6) on the 53 kHz lowpass filter (FL-3) to half mesh. 3. Set the audio oscillat or to 500 Hz at +10 dBm, feeding left channel only. 4. Set the stereo generato r in MONO mode and monitor the composi te output at J102 on a scope. Externa lly synchro nize the scope sweep with the audio STEAM POWERED RADIO.COM 15 oscillator. Adjust the front-panel OUTPUT LEVEL control on the stereo generator until the output signal measures 3. 5 volts peak-to-peak on the scope. 5. Set the stereo generator in STEREO mode and adjust the STEREO GAIN control (R61) for an output of 3.5 volts peak-to-peak at J102. 6. If scope performance has previously been verified, skip this step. Check oscilloscope phase shift and overload characteristics by moni taring the signal at pin 2 of the electronic switch U9. Set the scope vertical amplifier sensitivity to 5 mV/cm, de. Ideally, a flat baseline should be observed because the actual separation at this point is well in excess of 60 dB. A scope which displays a baseline whose variation is 2.5 mV peak-topeak or less is acceptable for the remainder of these adjustments. This amount of variation limits the accuracy of further separation adjustments to 58 dB. If the scope displays more than 2.5 mV peak-to-peak baseline variation, which is not caused by poor overload characteristics, it may be possible to correct this by properly adjusting the high-frequency compensation circuits in the scope's vertical amplifiers. 7. Once the performance of the scope has been verified, keep it set at 5 mV/cm de and monitor the stereo generator output at J 102. Adjust the LEFT SEPARATION control for a flat baseline at 500 Hz. See figure 3, photo 1. 8. Set the oscillator to 14 kHz, and adjust the variable capacitor (C6) on the 53 kHz lowpass filter (FL3) for a flat baseline. NOTE: In case of failure of a component in FL3, the entire filter assembly must be replaced. 9. Repeat Steps 7 and 8 until the baseline is flat at both 500 Hz and 14 kHz. 10. With the oscillator at 500 Hz, feed a right only signal and adjust the RIGHT SEPARATION control for a flat baseline. 11. While observing the baseline amplitude, manually sweep the oscillator from 500 Hz to 15 kHz for both left only and right only input conditions. Verify that the worst case baseline amplitude is no greater than 15 mV peak-to-peak (3 cm peak-to-peak). This corresponds to a separation figure of 47 dB and usually occurs around 8 kHz. PILOT ADJUSTMENT 1. Feed signal to both inputs in phase (L+R signal). Set oscillator to 500 Hz at 2.45 volts rms and switch stereo generator to MONO mode. 2. Verify that the stereo generator output at J 102 is 3. 5 V peak-to-peak . Adjust front-panel OUTPUT LEVEL control, if necessary. 3. Connect the output (J102) of the stereo generator through a 5000 ohm pot to the baseband input of a BW-85A (BW-185) stereo monitor. Set the monitor's function switch to TOTAL and the range switch to MOD. Adjust the pot until the monitor reads 100% modulation. STEAM POWERED RADIO.COM 16 Composite Stereo Waveform 2 3 (L -R} Subcarrier with Pilot {l+R) Main Channel with Pilot 4 6 Composite Stereo Waveform, Insufficient (L - R) Composite Stereo 1,aveform, Excess (L -R) Composite Stereo Waveform, Phase Error Between (L+R) and (L-R) 1 8 (L-R) Subcarrier with Pilot, Pilot in Phase (L-R) Subcarrier with Pilot , Figure 3, Pilot Phase Incorrect 11<247 Oscilloscope Waveforms 4. Switch the stereo generator to STEREO mode and adjust STEREO GAIN control (R61) until the monitor indicates 91% modulation. 5. Switch stereo monitor function switch to generator's PILOT LEVEL control (R46). 6. Using a plastic tuning tool, adjust PILOT PHASE control (L 1) for maximum pilot level. PILOT, and center the stereo 7, Adjust PILOT LEVEL control (R46) for a pilot amplitude of 9% on the stereo monitor . STEAM POWERED RADIO.COM 17 8. While watching the Hz deviation meter on the stereo monitor, adjust PILOT FREQUENCY control (C54). Make sure that pilot frequency can be adjusted to either side of 19 kHz, and then set it 0.5 Hz high. 9. Reverse the signal leads to the right input (L-R signal) and monitor the stereo generator output (J102) with a scope. Using a plastic tuning tool, adjust PILOT PHASE control (L1) for correct pilot phase as reflected by the scope "bow tie" pattern. See figure 3, photos 7 and 8. 10. Check that pilot amplitude is still 9%. (R46), if necessary. Adjust the PILOT LEVEL control REMOTE FUNCTIONS 1. Verify that the metering samples (J101 pins 7 and 9) are approximately 0.8 volts rms . Pin 7 is the left sample and pin 9 is the right sample. 2. Check external mode lines for proper operation. Short pin 12 of J101 to ground for mono mode and short pin 10 of J101 for stereo mode of operation . FINAL CONSIDERATIONS The stereo generator, as it now stands, is optimally aligned in all regards. Separation and crosstalk from all causes for frequencies between 50 Hz and 15 kHz will be in excess of 45 dB. Therefore, no further adjustments should be performed on the stereo generator. During the final performance verification, the BW-85A (BW-185) FM monitor will be used to secure the majority of readings included on the final test data sheet. If, during final test, the monitor produces unfavorable readings avoid any temptation to adjust the stereo generator. Rather, recalibrate the monitor in accordance with instructions supplied with it. STEAM POWERED RADIO.COM 18 PARTS ORDERING INFORMATION REPLACEME NT PARTS Repl acement parts bearing a Stock Num ber should be ordered by Item, Description, and Stock Number from RCA, Distributor and Special Products Division, Deptford, New Jersey 08096. Items listed under a Master Item (Ml) Number should be ordered from RCA, Commercial Commun icati ans Systems Division, Camden, NJ 08102. ing modification of the customer's design. In some cases, parts and/or instructions for adapting the substitute parts will be supplied. In no way will the substitute parts impair the operation or performance of the equipment. For information regarding the use of any parts received, write RCA, Tech Alert, Bldg. 2-8, Camden, NJ 08102, or call (609) 338-3434. EMERGENCY PART SERVICE Because of possible products modifications and/or the unavailability of parts," the item which will be supplied aga inst an order for a replacement part may not be an exact duplicate of the original part. As a result, some of the replacement parts received may require a mount· LOCATION Continental United States, including Alaska and Hawaii For emergency part service during working hours, contact RCA Distributor and Special Products Division, telephone (609) 848-5900 or (609) 541-3636 extension 2234 or 2235. After working hours (Eastern time) telephone (609) 853-0560. ORDERING INSTRUCTION S I IPnlacement Parts bearing a STOCK NUMBER should ue ordered from RCA Distributor and Special Products Division - 2000 Clements Bridge Road - Deptford, NJ 08096. Replacement Parts bearing a MASTER ITEM (Ml) NUMBER should be ordered from RCA, Commercial Communcation s Systems Division - Camden, NJ 08102 or your nearest RCA Regional Office. Replacement Parts with NO STOCK or MASTER ITEM (Ml) NUMBER are standard components. They are not stocked by RCA and should be obtained from your local electronics d istributor. Dominion of Canada Order from you r local RCA Sales Representative or his office or from : RCA Victor Limited, 1001 Leno ir Street, Montreal, Quebec. Outside of Continental United States, Alaska, Hawaii, and the Do• minion of Canada Order from your local RCA Sales Representative o r from: RCA International Division, Clark, New Jersey - U.S.A. - Wire: RADIOINTER STEAM POWERED RADIO.COM Emergency: Cable RADIOPARTS , DEPTFORD, NJ 19 REPLACEMENT PARTS S ymbol Stock N o. Description Drawing No. BTS-101A STEREO GENERATOR Ml-561061A MAIN FRAME Cl Ol THRU Cl05 241490 410PF 20¾ 560V FEED•THR.U CRlOl CRl02 44lb35 441b35 LED~ AMB~R , STEREO LED ,. AMAF.R, MCNO FlOl FlOl 427383 98t05 FUSE ,. 1/4 AMP 250 V ( 120 \TAC I NPUT) FUSE• 1/8 AMP 250 V (2~0 VAC INPUT) FL101 THRU FL106 427389 JlOl J102 444316 223973 Ll01 THRU Ll05 425969 3000PF 500V FEED-THRU CONNECTOR - INP UT CONNECTnR ~ OUTPUT INDUCTOR lOIJH RlOl IHOZ Rl03 444324 444324 444324 1000 OHM VAR (SEPARATION LEFT) 1000 MHM VAR (SEPARATION RIGHT ) 1000 OHM VAR (OUTPUT LEVEL ) s101 444333 SWITCH TlOl Tl02 Tl03 44t.32T 42b792 426792 TRANSFORMER• POWER TRANSFORMER• AUDIO TRANSFOR MER• AUDIO u101 u102 4Z9929 444326 I,C, ~ TVPE LM309K l,C, ,. TVPE UA7812~C XFlOl 429892 HOLDER, FUSE XUlOl XU102 248368 248368 SOCKET~ KIT, FOR UlOl SOCKET " KIT, FOR Ul02 r- Tn5GLE, STEREO/MONO MODE STEREO PW BOARD Cl 230245 CZ 4Z3708 C3 C4 C5 Cb C1 cs C9 ClO Cll Cl2 Cl3 Cl4 Cl5 Cl6 Cl7 Cl B Cl9 C20 STEAM POWERED RADIO.COM 423708 213496 228720 420561 435312 io23708 435312 423708 433046 230048 215380 426858 446680 42602'1 423708 424800 424800 423708 150 PF 5% 500V MICA 100000P~ 20n 25V CER lOOOOOPF 20, 25V CER 47PF Z% 500V MICA Z40PF 1% 500V MICA ,47 UF 3% 100V FlLM 10 UF 10• 26V TANT lOOOOOPF 20~ 25V CtR 10 UF 10% 26V TANT lO OOOOPF 201 25V CcR 5PF •••'PF 500V MICA 9lOPF 51 5oriV MICA 1800 PF 5t ,oov MICA lllOPF 2% 500V MICA 100000 PF 20% 50V GLASS lOOOOPF 20¾ 50V CER lOOOOOPF 20~ 25V C£R 220Uf 20% 1 0 V TANT 220UF 20¾ lOV TANT lOOOOOPF ZOt 25V CER 20 Symbol C21 en C23 C24 C25 C26 (27 c2a C29 C30 C3l (32 C33 C34 C35 C36 C37 C38 C39 C40 C41 C42 C43 C44 C45 C46 C47 C48 C49 cso C51 C5 2 Stock No. 4237.)8 228718 230245 440047 432015 1t237U8 228720 4237 0 8 420561 423708 423708 4330(16 230048 2153BQ 426858 423708 426027 423708 1,24 800 4248 00 ',26033 423708 426027 42370 8 435312 423708 426027 435312 423708 424275 426027 435312 238220 440047 C53 C54 C55 C56 4237 0 8 C57 426027 435178 C58 C59 435312 C60 435312 Col 242964 C62 242964 1,23664 (63 420492 C64 C65 '·'1:''l.U 423664 C67 CRl 'i',fRU CR4 234552 CR5 242220 CR6 242220 CR7 2 34552 Drawing No. Description lOOOOOPF 20% 25V r: ER 75PF 5% soov MICA 150 PF 5¾ 500V MIC:A l5PF - 60PF VARIABL E, 15 KHZ FLAT lOPF +~,5PF 500V MICA l OOOOOPF 20¾ 25V CER 240Pf 1¾ 500V MICA lOOOOOPF 20¾ 25V CER ,47 UF 3¾ lOOV FIi M lOOOOOPF 20% 25V t.ER lOOOOOPF 20% 25V CER 5PF +- . 5PF 500V MICA 910PF 5¾ 500V MI CA lBOOPF 5¾ 500V MICA lllOPF 2% 500V MICA l OOOOOPF 20% 25V CER l OOOOPF 20% SOV CFR lOOOOOPF 20 ¾ 25V C:ER 220UF 20% lOV TANT 220UF 20% lOV TANT 2PF 10¾ 500V MICA lOOOOOPF 20% 25V CER lOOOOPF 20% 50V CFR lOOOOOPF 20% 25V CER 10 UF 10% 20V TAN T lOOOOOPF 20% 25V CER lOOOOPF 20¾ 50V CFR 10 UF 10% 20V TANT lOOOOOPF 20¾ 25V CER 3PF 5% 500V MICA lOOOOPF 20¾ 50V CFR 10 UF 10¾ 20V TANT 470 PF 5% 500V MI<'.A 15PF - 60PF VARIAR LE, PILOT FREQUENCY TRiM VALUE (OPTIONAL) lOOOOOPF 20% 25V CER lOOOOPF 20% 50V CER 3300PF 10% lOOV MTCA 10 UF 10% znv TANT 10 UF 10% 20V TANT 500 UF 75V ELECT 500 UF 75V ELECT lUF 10¾ 35V TANT 2,2UF 10¾ 35V TANT lUF 10¾ 35V TA·NT DIODE• DIODE ., DIODE• DIODE • TYPE TYPE TYPE TYPE 1002 1N4154 lN4154 1002 Kl 1 ,44311 RELAY L1 4466137 COIL 15•40 MH PILOT 01 02 420558 241778 2N3053 2N4037 TRANS I STDR TRANSISTOR TRANSISTOR TRANSISTOR 08 2N3053 TRANSISTOR - TYPE 2N3053 RS 435554 440074 t,46684 446678 108865 440074 825 OHM l¾ l/8W FILM 475 OHM l¾ 1/BW FILM 1000 OHM VARIABLE, LEFT GAIN 1020 OHM 1% 1/BW FILM 1000 OHM 5% 1/4\./ COMP 475 OHM l¾ l/8W FILM 03 04 - TYPE TYPE TYl'E TYPE PHASE 2N3819 2N3563 2N30 53 2N4037 05 THRU R6 R7 RA R9 RIO STEAM POWERED RADIO.COM ~ 21 Stock No. Symbol 428519 RI l Rl2 436330 1146679 Rl3 108865 Rl4 1136791 R15 1+36310 R!6 Rl7 1088':>l RlB 4376l!2 Rl9 230605 R20 4 376 '!2 R?l 108861 R26 4355'i4 R?7 440074 1+466'l4 R?8 R29 '146678 108865 R30 R31 '+400 74 R32 428519 R33 43t33o 44t679 R34 4268'.;;J R35 108864 R16 436791 R37 R38 436330 R39 108861 ,,376 tJ2 R40 2306 0 5 R'+l 1, 3768? R42 108861 R43 R44 436331 R45 232289 431:7 9 5 R46 R47 1i:'m 10886<; R50 108866 R5l 2 J875R R52 108861 R53 4350'>6 R54 R~5 1088'>5 1088 1>1 R~6 446678 R57 4334 •11 R58 R59 l1363Jl R60 108867 436791 R6l 1088b l Ro2 113768? R63 R64 43763? 1144542 R65 R66 427566 427566 R67 44454? R68 113524 R69 4416g4 R70 R71 512147 218499 R72 R73 426213 R74 108866 R75 2184'19 2 18499 R76 R77 426213 R78 T:-:'RU 218499 R80 RAl 108866 '.>12147 RAZ R83 4 262 33 426233 R64 Drawing No. Description 4750 OHM 1% 1/lOW FILM 22100 OHM 1% l/8W FILM 34000 OHM 1% 1/RW FILM 1000 OHM 5% l/4W r.OMP 10000 OHM LINEAR VARIABLE, LEFT PRE - EMPHASIS 22100 OHM 1% l/8W FILM 100 OHM 5% l/4W cnMP 4990 OHM 1% 1/BW FILM 27 OH~ 5% l/4W COMP 4990 OHM 1% 1/RW FILM 100 OHM 5% l/4W COMP 825 OIIM l% 1/8W FILM 475 OHM l ¾ l /8W FILM 1000 rl HH VAPIABLE, 150 HZ 1070 • HM 1% 1/AW FILM 1000 nHM 5% l/4W COMP 475 OIIM 1% J /8W FI LH 4750 UHM 1% 1/!CW FILM 22100 OHM 1% 1/AW FILM 34000 OHH 1% 1/BW FILM 1000 OHM LINEAR V6RIABLE, 15 KHZ 470 OIIM 5 % 1 / 11W U lMP 10000 OHM LINEAR VARIABLE, 1500 HZ 22100 OHM 1% l/8W FILM 100 OHM 5% 1/4W COMP· 4990 OHM 1% !/AW FILM 27 OHM 5% l/4W COMP 4990 UHM 1% 1/AW FILM 100 OIIM 5% l /4W cnMP 47500 OHM 1% 1/AW FIL M 470000 OHM 5% l/4W CO MP 100000 OHM L INEAR VARIABLE, PI LOT LEVEL 1000 • HM 5% l/4W r.OMP 2200 nHM 5% l/4W COMP 220 OHM 5 % I/4W COMP 100 OHM 5% l/4W cnMP 1000000 OHM 1% 1/4 FILM 1000 OHM 5% l/4W COMP 100 OHM 5% l/4W cnMP 1020 flHM 1% 1/AW FILM 5620 nHM 1% l /8W FILM 47500 OHM 1% l/8W FILM 6800 OHM 5% l/4W r.OMP 10000 OHM LINEAR VAR IABLE, STEREO GkIN 100 OHM 5% l/4W cnMP 4990 • HH 1% l/8W FILM 4990 flHM 1% 1/8W FILM !BO OHM 5% l/4W cnMP 68000 OHM 5% l/4W COMP 68000 OHM 5% l/4W COMP 180 OIIM 5% 1 / 11W cnMP 2700 • HM 5% l/4W COMP 820 OHM 5% l/4W cnMP 470 OHM 5% l W cnMP 10000 OHM 5% l/4W COMP 4700 OHM 5% l/4W r.OMP 2200 UHM 5% l/4W COMP 10000 OHM 5% l/4W COMP 10000 OHM 5% l/4W COMP 4700 • HM 5% l/4W COMP 10000 OHM 5% l/4W COMP 2200 OHM 5% l/4W COMP 470 OHM 5% lW COMP 22 OHM 5% l/4W COMP 2 2 OHM 5% l/4W COM P 51 TIErn S6 432426 STEAM POWERED RADIO.COM SWITCH - SLIDE DPDT 22 Symbol Stock No. TPl TP2 TP3 TP4 TP5 TP6 TP7 Ul 'rHRU U6 U7 us U9 UlO U11 Ul2 Ul3 Ul4 Ul5 U16 Drawing No. Description 425993 42599;:, 425994 425990 4259'l9 425988 4z59g7 JAC:K JACK JAC:K JACK JACK• JACK JACK - ORANGE YELLOW GREEN BLUE VIOLn GREY WHITE lt355 1)4 423797 1,23797 446683 4355 0 4 435504 425796 422417 425797 433814 438486 I , C, I,C . I , C. I , C, I , C. I , C. I , C, I , C, I , C• I,c. I , C• TYPE TYPE TYPE TYPE TYPE TYPE TYPE TYPE TYPE TYPE TYPE - LM318N UA741r.P UA74lCP Hl.:.201- 5 LM318N LM318N SN7404N SN7490AN SN7493N SN7474J UA7917.UC XO! 'I'HRU X08 446686 SOCKET - TRANSISTOR XUl 'I'llRU XU8 XU9 XlJ l O XUll SOCKET • SOCKET SOCKET ~ SOCKET • XU12 44433;> 446685 1,443·)2 444332 I,C. I , C. I • C. I • C, SPIN )6PJN SPI N BPIN THRU Xlll 5 444315 SOCKET - I • C. i4PJN XYl 444314 CONNECTOR Yl '• 4'1312 CRYSTAL - 3,04MHZ - (XTALl - TWO REQUIRED DUAL INPUT PADS Rt 'T'HRU R4 426234 Ri'2 'I'HRU R25 426234 820 OHM 10¾ l/4W 820 OHM 10¾ l/4W (.• MP, r. • HP. 53 kHz LOW PASS FILTER FL3 446681 53 KHZ LPF FLl , FL2 CI C7. C3 C4 cs 15kHz LOW PASS FILTER Ml-561O64 441639 l2 7692 441641 441642 441640 STEAM POWERED RADIO.COM 1930 360 2530 1815 2200 PF 2¾ 500V MICA PF 5¾ soov MYCA PF 2¾ 500V MIU. PF 2¾ 500V MICA PF u 500V MT CA 23 Symbol Cb Stock No. Drawing No. Description C7 444303 444303 1300 PF 5¾ 500V MTCA 1300 PF 5¾ 500V MYCA L2 L4 L6 444306 444305 114430 4 INDUCTOR, VARIABLE INDUCTOR, VAR I ABLE IND UCTOR, V'.HI"BLZ INTERCONNECT CABLE FOR BTE-115 STEREO SYSTEM Ml-561067 3729869-506 REV 1 5Pl 5P3 5P4 5P5 5P6 5P7 THRU 5Pl2 446036 445153 445 155 445152 445152 3729870-0011 3729870-0008 3'729870-0010 3'729870-0006 3'729870-0006 CONNECTOR, 24 CONTACT MALE CONNECTOR, 6 r. • NTACT FEMALE CONNECTOR, 12 r. • NTACT Ff;MALE CONNECTOR, 8 r.nNTACT HMAl,E CONNECTOR, 8 ('.ONT ACT FEMALE 431554 444754 993150-0061 3729870-0012 CONNECTOR, BNC CONNECTOR, 24 CONTACT FEMALE STEAM POWERED RADIO.COM 24 SUGGESTED STATION SPARES Stock No. Quantity Domestic Foreign Descrieti on Symbo l Crystal, 3.04 MHz Yl 444312 1 1 Fuse, MDL, 1/4A ( 120V Input) FlOl 427383 5 5 Fuse, MDL, 1/8A (240V Input) FlOl 098105 5 5 Transisto r, 2N3819 Ql 420558 1 1 Transisto r, 2N3563 Q2 421778 1 1 Transisto r, 2N3053 Q3, 05 thru 08 2N3053 2 2 Transisto r, 2N4037 Q4 2N4037 1 1 Potentiom eter, lK 10-turn trimmer R35 426851 1 1 Integrated Circuit, LM318 Ul thru U6, UlO, Ull 435504 3 3 Integrate d Circuit, Hl-201-5 U9 446683 1 1 Integrate d Circuit, UA741CP U7, U8 423797 1 1 Integrate d Circuit, 7404N Ul2 425796 1 1 Integrate d Circuit, 7490AN Ul3 422417 1 1 Integrate d Circuit, 7493N U14 425797 1 1 Integrate d Circuit, 7474J U15 433814 1 1 Integrate d Ci re ui t, LM309K regulator UlOl 429929 1 1 Integrate d Circuit, 7812 regulator U102 444326 1 1 Integrate d Circuit, 7912 regulator U16 438486 1 1 STEAM POWERED RADIO.COM 25 N 0 0 I- oo ___ - LL. "-x ....... L:C I- 31: U) >- Q. U) (.) a:: I-(!) 0 • ic, .J 0 &&. N .J • .J U) ..J N .J ~/- IO 0 I- "' 0 .., -(!) Q. N a:: 1-0 ., ' Figure 4. STEAM POWERED RADIO.COM ..J LL. BTS-101A Top View 26 - OUT + • S5 LPF R7 LEFT GAIN IN 0~50 LI C54 PILOT FREQUENCY PILOT PHASE C60 © 3K049 C24 15kHz (FLAT) R35 15kHz R28 150Hz OUT +ss R37 l500Hz tLPF R61 STEREO GAIN R46 PILOT LEVEL * NOTES:!. DENOTES OPTIONAL OR TRIM COMPONENT. 2. FOR COMPONENT LAYOUT, SEE FIGURE 12. - IN Figure 5. PW Board Switches and Adjustment 20A2642 Figure 6. IK213 Dual Input Pad Components STEAM POWERED RADIO.COM - 27/28 ' I Ti03 CIOI ,.l_;70PF LIOI IOuH JIOI -, RI 820 6 I 1o2 LI02 i I I I I '- 47PFl1----- ACTIVE RII RIO 475 + + 12V 1501 PF 1K 1% -12V 470PF-1-B-f''l--{30 ,--;v\,--. R43 100 -12V _ _J S4 240 VAC FILTER +12v + 24V TP6 GRY BLK C61 500 75 + C63 1/35 CR4 IOD2 C62 500 75 + I. R46 IOOK t--- -----1• +5V + C65 l l PILOT LEVEL C51 DRIVER 1/35 , l -0 1 B E U102 R55 IK - - _J - C66 1/35 3,04 MHr 30A0043 3 U 16 7912UC 2 +5V C67 l/ 35 f"-------4~---<• -12 V 01 2N38 19 C56 } RSI 2200 4 3 5 6 12 II 5 14 II 7490 Ul2B 14 3 6 9 7 10 2 3 u1sl 7474 3 ( -;-2) (74) (-;-10) 7404 2 Ul4 7493 10 14 :(-'-2) 13 10 4 R50 R52 220 AMllt:R 7 I I Q7 2N3053 R73 R77 4700 4700 R79 IOK I I I I I I 12 I I I I 20 5101 MONO STEREO MODE .,, ---~:;~~-----1~>--- ... 12 10 JIOI I PILOT FREOUENCV 9 8 Ul3 2 R53 100 12 5 l' 14 7 C5 3 r470PF C64 2.2/35 IK DIVIDERS YI + i I R49 R48 +sv ~ _ _ _ _ _ _J IK 02 2N3563 +5v I I I _J UNLESS OTHERWISE SPECIFIED ,o 20 Ul2A 7404 +5V BUFFERS 2200 u L.[.0. HP50824557 I R72 IOK +sv C58 3300 PF +12v 7 7812 R47 IK IK +sv - TP7 WHT -24V NOTES : IOK ~ - ----,2,C 7404 ~1----+--<-19_K_H_z_ _,__~ R56 100 CR3 1002 BLK / WH RBO C60 06 2N3053 C 57 .QI OSCILLATOR E L 8LK / RED FLI04 T +5V -12V C I CRI 1002 UIOI 309 B 5 WHT R79 IOK R76 IOK R75 IOK A, PILOT PHASE L RII + 5V 7 I I (USE . 125 AIIP FUSE) WH IMONO +12v 5010-50 i GRN I LATCH tl2V l9KHr 4701< PRE-EMPHASIS WIRING FOR CR2 IOD2 MODE AMBER R45 REGULATORS .25A S. B. 19 _J CRIOZ L.E .O. HP50824557 1 TIOI PR IMART 120 VAC ~J r ,, + T + ! 2V LI [ 7 I TP4 8LU R84 6 ' : f - - - - - - - { ! F ~ L ~ l ~ O ! Z } - - - - - - - - - - - - - - - - - - - ( 3 1 > - - - - - - - - - - - - - ~ - - - - - - - - -- - - - - - - --'v'\/',,--------,---=-<:._ 22 u0 741 FIOI CRIOI IW R74 2200 9 8LK ,1 STEREO 1% '-; $WITCHES TIO I 3-1067 I R44 47.5K 16 , ,., r I I Rl2 470 PF2%J OHH122 5 S3 C40 220/10 >-6_ _ _ _ _.__+~~-------~29 1% R37 IOK C34 1800 U6 318 FL 2 AUDIO LPF 20A2633 R38 22.1 I( t +12v R7I 470 38KHr C39 220/ 10 1% R36 470 s 910PF D------'f R42 4990 R35 ~ C33 06 +12v S6 .:' J 15 KHz _J R ~ + 12v R40 4990 U4 1% 34K ~ R4I 27 R39 100 6 1% 1% -- -- - 7 3 2 us 318 4 R29 1020 R25 820 ' R28 IK 150 Hz t¾ 22.1 K TP2 YEL 1 240PF '8KHr 1110 PF 2 °/,i;, C30 C27 6 5 R23 820 7 ti 1% T 102 SAT-109 R22 820 470PF t12V C26 C35 tl2V tlD71J• ltlY A 3K051 L RESISTOR VALUES ARE IN OHM$ , l/4W, 10% . CAPACITOR 2. STEAM POWERED RADIO.COM VALUES ARE IN MICROFARADS. * OPTIONAL Figure 7. BTS-101A Stereo Generator Schematic Diagram 29 - L4 L2 3-4005 L6 3-4006 3-4007 A B C2 360 C6 1300 C4 1815 I Tc1 IC3 IC5 '.93025302200 IC7 ~ 300 --------------------Qc NOTES I. UNLESS OTHERWISE SPECIFIED CAPACITOR VALUES ARE IN 9IA7081 PICOFARADS. IK214 - Figure 8. Audio Lowpass Filter Schematic L6 L4 L2 3- 4007 3- 4006 3- 4005 NOTES: I. UNLESS OTHERWISE SPECIFIED CAPACITOR VALUES ARE IN PICOFARADS. STEAM POWERED RADIO.COM 2042655 IK21!5 Figure 9. Audio Lowpass Filter Components Location 30 - C6 5- 6 0 p F L 2 LI 3- 4001 3-4000 C2 I 10 3-4003 C4 L4 200 PF PF C3 Cl L3 C5 3-4002 C7 0 9IA7064 Figure 10. 53 kHz Filter Schematic 20A2632 Figure 11. STEAM POWERED RADIO.COM IK216 53 kHz Filter Components Location IK217 - 31/32 - 20B2723 REV II NOTES; I. UNLESS OTHERWISE SPECIFIED RESISTOR VALUES ARE IN OHMS, l/4W, DENOTES OPTIONAL OR TRIM COMPONENT. 2. * - 10%, a 3KOISO CAPACITOR VALUES ARE IN MICROFARA S. Figure 12. BTS-101A Stereo Generator Components Location STEAM POWERED RADIO.COM 33/34 I s,.;1 OFF FRE(l 5PZI BLK ~ f--t---------------'-Rc::E:.::D:...__ _--i--<; .~-o---W~~----+~ 5 6 I IL.a ~I_ _ _ _G_R_N _ _ ___.-< li'/1014TE n ! (-:-+---------1LJ z { TO EXCITER CONTROL PLUG SWTMJYN 6 I ~----'-=------1/0 SKI TO TRI/NSMITTER //FC z BR//SS 5<13 1 5XKI om I 5<12 BRl1SS WHT/BLK , ~---+--------'---'..c.,_;::_::c___~ r--'-< 1/LVER ' m I (GREEN /IVHT 5 llC POWER S01/RCE 717 INTERF/lCE/R/10//1TE P/1NEL Ml-56107/ -f; ·f) fl/1010 INPUT l1C 0IITLETS FOR POWER C0R£!.S ON EXCITER UNITS ,.;j .L< SILVER m I ----------------ft-< 7} TO EXCITER 9 --+.:}---' -f,---fi RF OUTPUT TO Ml-561067 INTERCONNECT rJ TRl1NSM/TTER Cl1BLE OUTPUT ,/l1CI( fx1:?1::R 5P4 - LEFT /11/0/0 IN 5PI I 2 { _ ' 'I I : ! (-(-,'-, 6 3 ~z 3~ 4 RIGHT 1/(/0/0 { IN : 1 I ;4 I __,_'T_,._'-----+T+---1(/ I , 5 INPUTS TO STEREO GENERl1TOR STEREO ON l6E-+---1:.C,,-----,h-, ----« /0 1 1 MONO ON 17 : T T 1./Z 1 COM l 8 ~ '-----KIi 0 5P3 I 7 ,_,,_...,-_,_,_ _ _......,__ _;.._, 3 METERING 8 OUTPUTS S., r FROM 8STEREO 7 ~_~ _,">----e+= 1----J IYIOEB/1NO MONO{l ,-, , , 1 7 /ll/010 8 (-(-+---+f::1----------------1,-IT-+-<,. 9 11UO/0 IN IN 9 ~ 6 1 {/,'O i'. "_ J SC/1#/ /11/0/0 II IN 12 +--1 I _ SP5 } 5 , f - - - +: , 6 I SC/1#/0N /9 1 SC/1#/0FF 20 ' , COMZI~ 1 : i i ·I 1 , - {2 OUTPUTS FROM SC.4#/ 3 4 7 8 i 1 INPUTS TO SC/1#/ I I 1 1 >+---------i=+-+--< 2 METERING ;i__r ~>-'5.'--P_9-A----~t""5."-P.-'-<1/0 SC/1 5 6 P s} sc11H2{13 1111010 14~(-''.---+'+r'_ _ _ _..,·,_'- - ' 6 IN /5 L________!, 4 INPUTS TO 1 1 r-,' SC.4#2 SC/1 112 ON 22f-l---<-=.--------<,'-',~--K, 7 SC/1"2 OFF 23. : 'T' 8 COM 2 4 ~ ,.,'-..,--+----+-+--__.__, 4 !WETER/NG 01/TPUTS 3 ~ FROM SP/I 5PIZ SC/1 # Z ~>---A----~tA----< SCII {2 STEAM POWERED RADIO.COM INTERCONNECT Cl1BLE /ISSEAIBLY Ml-561067-2, -3,-4,-5 OR -6 Figure 13. Interconnecting Cable Schematic /NP/ITS TO M/1/N EXCITER. UNIT 35/36 iil2V +12v p .I..AJF p 4.7K .l,uF 5.IK 5pF 5.IK* B INPUT 4.7K 100.1\. A-B OUTPUT p 4.7K* .I..AJF -12V +12V +l2V 4.7K p IK .lpF 200Hz NULL TRIM IOpF 5pF 860.J'\.* 5 . IK* 20kHz NULL TRIM NO E: A INPUT * 4.7K p . lpF DERIVED FROM 91B737 -12V STEAM POWERED RADIO.COM DENOTES METAL FILM RESISTOR 200Hz NULL TRIM POT SHOULD BE CERMET . 11<248 -12V Figure 14. Precision Differential Test Generator Schematic 37/38 • - ISOLATION TRANSFORMER H.P. AC-60 OR RCA MI-ll713A = TO 50.r\. SWEEP GENERATOR 8 .2.r\. ~ MANUAL 180.r\.lSWEEP ~ 600.r\. 600.r\. 45mH 150.r\. DE-EMPHASIS 600.r\. 600 f\. 300.r\. BALANCED OUTPUT INDUCTOR UTC, HVC-4 ADJUST FOR CORRECT 75)Js RESPONSE. SHIELD 0.125)JF 150.r\. IK24!5 Figure 15. STEAM POWERED RADIO.COM De-emphasis Network Schematic 300.J"I. BALANCED OUTPUT ,. - RCII C>mrrPrcialCorr-rnu'lca•orsSystems'J1v1s1c, Prir•ed 111 LS A STEAM POWERED RADIO.COM - Comme cial Communications Systems Division f-ro1tandCoopu' r t C 1d n !\iv USA 1)810 / -
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.5 Linearized : Yes Author : RCA Create Date : 2018:04:21 13:25:56-07:00 Keywords : RCA BTS-101A Stereo Generator Manual, RCA BTS-101A, BTS-101A, BTS101, RCA Stereo Generator Modify Date : 2018:04:21 14:11:00-07:00 Has XFA : No XMP Toolkit : Adobe XMP Core 5.6-c015 84.159810, 2016/09/10-02:41:30 Producer : Adobe Acrobat Pro DC 18 Paper Capture Plug-in Format : application/pdf Title : RCA BTS-101A Stereo Generator Manual Description : RCA BTS-101A Stereo Generator Manual Creator : RCA Subject : RCA BTS-101A Stereo Generator Manual, RCA BTS-101A, BTS-101A, BTS101, RCA Stereo Generator Metadata Date : 2018:04:21 14:11-07:00 Document ID : uuid:1a14730c-b23f-4f41-8840-c1649549ab63 Instance ID : uuid:e42b70eb-3a2b-4441-ac82-c45e7e56e472 Page Count : 41EXIF Metadata provided by EXIF.tools