Moseley PCL-303/C, Instruction Manual

Page 1: ...www SteamPoweredRadio Com INSTRUCTION MANUAL MODEL PCL 303 C STUDIO TRANSMITTER LINK ...

Page 2: ...dio Com I I I I I I INSTRUCTION MANUAL I MODEL PCL 303 C STUDIO TRANSMITTER LINK I I I I I I MOSELEY ASSOCIATES INC I Santa Barbara Research Park 111 Castilian Drive I Goleta California 93017 I Revised I October 1972 I I ...

Page 3: ... Performance Specifications Unpacking and Initial Checkout Installation Antenna Detailed Description of Transmitter A B C Transmitter Operation Transmitter Circuit Description Transmitter Remote Control D Transmitter Adjustments and Alignments Detailed Description of Receiver A Receiver Operation B Receiver Circuit Description C Receiver Adjustments and Alignments Shipping Instructions Final Te st...

Page 4: ...lization of two aural ST L systems to convey the unmatrixed LEFT and RIGHT audio signal This results in an equipment cost savings It should also be noted that a 67 kHz SCA subcarrier can also be applied to the ST L for direct rebroadcast _ by the FM transmitter 2 The stereo generator is located at the studio site where adjustments if required can be made away from the strong RF fields found near l...

Page 5: ...g carrier fall below a given preset value In addition Form C contacts of this relay are terminated on the rear apron for use by external alarm or control circuits The transmitter incorporates a direct FM basic oscillator to achieve flat response and uniformly low distortion over a wide modulation frequency range Provisions are included on the transmitter to multiplex two ubcarriers for remote cont...

Page 6: ...ters employing a direct FM oscillator Further the unit is designed basically to operate with the Moseley Model SCG 3T Stereo Generator However it is possible to apply a signal from other stereo phonic generators meeting th requirements of FCC Rule 73 322 The input level requirements of the PC L 303 C transmitter must be observed to obtain satisfactory results PCL 303 C 3 ...

Page 7: ...quencies Spurious Response Stability Maximum Available Composite Output Signal Metering Operating Temperature Range Dimensions Weight Power Requirement Mounting PCL 303 C 4 890 MHz to 960 MHz crystal controlled Less than 8 0 µvotts for 20 db quieting 50 n Type N female connector 200 kHz 1st I F 72 MHz 2nd I F 10 7 MHz Spurious and image responses attenuated more than 60 db Maintained to within 0 0...

Page 8: ... J load Type N female connector Better than 0 001 0 C to 60 C crystals mounted in temperature controlled oven 12 times basic oscillator frequency Better than 75 db below carrier reference 70 kHz for l 00 modulation More than 60 db below carrier 246F9 255 kHz B W 290F9 300 kHz B W 10 000 J unbalanced approxi mately 3 5 volts peak to peak for 100 modulation Two BNC connectors are pro vided for subca...

Page 9: ...and should not be adjusted unless proper test equipment is available and then only after reading the Tuning and Alignment Procedure outlined elsewhere in this manual If a 10 watt 50 n RF termination capable of operation at 950 MHz is available with or without a calibrated wattmeter the STL transmitter can be bench checked With the RF load connected to the output of the ST L transmitter and the lin...

Page 10: ...se slides should be secured to the rear rails or to the cabinet walls with the brackets provided The external connections which must be made for both units include the 3 wire power cord RF input and out put cables unbalanced shielded composite program line and if used coaxial cables for multiplex subcarriers The transmitter should be installed in such a manner as to allow air to freely circulate a...

Page 11: ... frequency p wer amplifier chain as well as the cooling fan The RF output meter on the front panel provides an indication of carrier radiation This turn on procedure prevents the STL transmitter from radiating an off frequency signal prior to the capture of the basic oscillator by the AFC circuitry V ANTENNA The Type PR 450 Scala Antenna is normally recommended for use with the Model PCL 303 C STL...

Page 12: ...tion up the tower The ICU 1 Isocoupler has less than 0 5 db of insertion loss at 950 MHz and presents less than 10 pf of capacity to the base of the tower The ICU 1 is rated for a peak instantaneous voltage breakdown of 5 000 volts The modulation voltage peaks should be taken into consideration when using the ICU 1 VI DETAILED DESCRIPTION OF TRANSMITTER A Transmitter Operation To place the Model P...

Page 13: ...the main channel program level when a subcarrier is added to the STL B Transmitter Circuit Description The complete schematic of the PCL 303 C transmitter is shown in Drawing 91C 62 42 The composite stereo input signal is first applied to the deviation control R 145 It is then passed through a time constant correction network to the variable capacitance diodes varicaps CR 101 and CR 102 These diod...

Page 14: ... circuit emitter coupled crystal controlled multivibrator The output of this oscillator is applied to level changer Q 2 and applied to IC 10 and divided 4 times Thus the outputs of IC 9 and IC 10 operate at the same frequency The phase of these two output signals is compared in IC 11 to achieve an integrated DC AFC error voltage which is amplified by Q 3 It should be noted that the entire AFC syst...

Page 15: ...will operate relay K 401 applying 26 2 volts DC to the RF power amplifier To indicate the relative power output at the remote position place a 50 µa meter in series with pins A and B of J 403 Connecting another 50 µa meter between pins J and A will provide the remote control point with an indication of the AFC error voltage The Model ECP 1 Extension Control Panel is available to operate the PCL 30...

Page 16: ...basic oscillator is in phase with the reference oscillator and no AFC error voltage is present AFC control of the basic oscillator can be quickly confirmed by switching to the AFC position If the meter follows a slight change of adjust ment in C 104 the AFC is locked In normal operation the I P A DRIVE position is used as an indication of the presence of normal drive to the RF amplifier The amplit...

Page 17: ... reinstalled between the transistor and the heat sink If Q 203 or Q 301 are replaced remove the finned heat sink on the old unit and install it on the replacement VII DETAILED DESCRIPTION OF RECEIVER A Receiver Operation After mounting the receiver connect the power supply cord to a convenient source of 120 240 VAC 50 60 Hz Turn on the power switch on the front panel Attach the antenna connection ...

Page 18: ...connector located on the rear panel type BNC connectors for the composite out put signal and two multiplex outputs In addition relay contacts Form C are also present on the rear chassis to indicate pres ence of a received carrier Quite often the ST L receiver is located in a building containing high RF field energy Under these conditions cross modulation products can be created in a conventional t...

Page 19: ...al controlled oscillator at 61 3 MHz The output of this mixer is then amplified by the 10 7 MHz second I F amplifier Q 303 Q 304 Q 305 and Q 306 This amplifier has a response de signed to obtain maximum phase linearity over the entire stereo phonic spectrum Preservation of phase integrity is paramount to proper stereo performance Q 306 acts as a limiter and drives a conventional ratio detector The...

Page 20: ... equal amplitude may be observed whe_ n aligning the coils of this receiver However single tuned coils adjusted from the top of the chassis should be aligned on the peak observed when the slug is nearest to the top of the coil with the screw protruding the most To align the first oscillator and subsequent multiplier stages the following procedure is used Oscillations are indicated by a re ading of...

Page 21: ... of the 10 7 MHz I F and ratio detector transformer it is not recommended as a field adjustment unless an I F sweep generator and an exact source of 10 7 MHz are available Considerable effort has been expended in the design of the 10 7 MHz I F to achieve a phase linear transfer char acteristic and to eliminate the need for tuning Replacement of Q 302 Q 303 Q 304 Q 305 and Q 306 does not require th...

Page 22: ...n best be done by wedging cardboard between the chassis and the top cover 4 5 6 Check to see that the relays in the receiver and transmitter are firmly in their sockets and that the retaining clamp is in place Replace both top covers Place equipment in shipping cartons Use adequate spacers at all edges to prevent puncture damage if carton is dropped in transit If possible use an inner carton with ...

Page 23: ...EIVER SIGNAL STRENGTH CALIBRATION µV input Sig l Sig 2 Sig 2 No AGC 50 14 6 6 100 20 13 14 300 22 37 49 500 22 40 67 700 22 40 72 1 000 GG 4 U lj 1 500 22 40 82 Measured with 50n R F signal generator Customer KABL Seri al RX 8237 TX 8233 Frequency 948 500 MHz Function 10 Volts 10 Volts RECEIVER 1st Oscillator Mixer Drive 2nd Osei 11 ator Limiter Signal l Signal 2 Discriminator Discriminator COMPOS...

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Page 26: ...00 CR407 IZSIOA 0404 2N30 54 IZS4 3A 260 MA R417 470 SET FOR 28 0VDC 3 SV 3 1V NOM AFC BO 407 12K Cl07 330pf Rl35 68K C304 39pf CRI06 IN41 54 2N4440 OR 2N 337 5 Cll3 150 15 Cl09 IOpf N750 11 LI03 3 9UH Cl42 22 100 IN4154 CB RI08 2 2K CIIO IOpf NPO Cl04 RI09 2200 R 15 3 75K AFC UNLOCKED 100 Cl49 20 l 47 R 112 ft161 CIII 330 pf J403 J REMOTE AFC METERING C4 _ t oo I VP P 1 9 5MHz l 4 _ I P A V cc C3...

Page 27: ... 0 L30S 4 T R330 680 C332 01 R 33 3 C 357 01 I I C220 r 01 C218 C227 C216 JoPF 00 33PF L 20 9 10 UH R 35 IO 0 R342 CR304 51 A5229 R340 CR303 AUD I O C S4 3 OJ R335 6800 R346 100 R359 10 K MTR SIG I M ULTI PLEX 001 24 C22 6 0 1 r Ii C347 0 01 10 K t R229 I f I OV R 3 50 7 I O V JO C348 C353 J 0 1 7 C R306 R352 R354 T 30 1 i 5 R35I 68 1I JN4I5 4 IK __J R360 I O K I I o MTR LI M ITER 001 330pf R35 5 ...

Page 28: ...3 PC L 202 91 C 62 54 91 C G2 3Eo PCL 3O3 C 91 C 624 2 5 NEXT ASSEMBLY 2 1 C 2111 Ii Oif fR tCH Pf t rt AQF Q T 1 A B2 PF OI 1 DC C z LiJ o a LU Qi J 104 1 13 PF j r LIO ZA 1238 2 N 0 1k 0 Ill 3f ELEVATE CR IOI CR 102 CR 103 CRI04 WITH BRASS SLUG 1 MO L V A OCIAT IN C 0 _ SANTA BARBARA RESEARCH PARK GOLETA CALIFORNIA 1 01 7 COMPONENT LAYOUT BASIC osc so PCL 303 202 XMTR 1 2 z TOL FRACT t 1 J2 XX O...

Page 29: ... GD llil 0 0 GD GD ill 1111 GD 0 i 0 CJ c Cl I c 1 z Ill 0 J 2 3J VO SN01St 3tj to 1 oow 41n 19 IM l ci r a N NMWQ3l 3 5 01 _j J 110 N l IM Q JV J OL I 6tf H 1 0 3 f17 1 L I NO c z s ti o o 3 1M L nnio i I 0 f t 0 3 3d oh B01 or Ii o h r 1 0 3 9 Jtt l J 30711 llt a lo_i1 3 L 2 1 03Sll3 3ll 3U M N c 3lllM t1M 8 l O 3 l l l ...

Page 30: ...FARADS 2 6 INDICATES WAVEFORMS SHOWN ON TRANSMITTER SCHEMATIC 3 P C BOARD DWG 51A5103 APPROX IV P P USING 100 MHz SCOPE I _ o of r ct w tJ Ill i 0 UJ A IIOSELEY A88QCIATE8 JN j SANTA BARBARA CALIFORNI A Ir COMPONENT LAYOUT o E STL AFC BO PCL 3036 202 XMTR t l o I0 a 0 xx 030 xxx 0 v Ol 0 Iii w a SCA E FULL a I Ill n O c __ j __ 20A2044 ...

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