SBS FM10 User manual.
Contents
1. 2 92 2 n d pa 13 wale TA TAL 9782 101 1 031 W3MUd 18 10 3 DLM3 k 19 1999 Issue 1 C18 DLM3 9 9 9 IN R40 R36F _ 21015 9 9 9 R34 oTP1 33 C16 R35 R4 CI 9 T9 RAST R24 R25 R19 2 lt RIT e R2 H U2 9 R26 C8 U4 9 2 28 29 gt 5 R31 R32 C12 9 C7 929 U3 9 9 C19 o o DC1 o 20 H H H H 9 059 R42. Lim Page 21 E U17 9999999 U16 H 9 9 e RIF 00 23722225 C37 1 43 99999999 ROTH 102 12 9999999 7 eR C35 C34 1 6 RIH R58 4589 TRIS FIL2 C Ra x col 2 ez az a 2 v 20 9 e A n m 9999999 18 9 9 9 9 D ua OQ 38 e eee pe a a Page 22 10 5 FM10 PA PUN Vd OWS 669070 BI 82 ib AY89X3108 CAC098SXZB WIZEO9INT 040934 NOISIA3H q 5 vdnod 999 95 diy 83 09 199 9493 oixpo WWOgZ 181228 NS 20 3NIT XY03 END 8v2 1102 21402 sr AYASX3TON NOL You og dozz 72 INIT xv03 INIT XY03 d P 1977 199 9499 01 002 door 2899 12 2 f AYR9X3108 a Oiar AVAZMOI3M Page 23 11 Declaration of
3. sbs FM10 FM EXCITER TRANSMITTER TECHNICAL MANUAL 5 Introduction Safety Electrical hazard Safety Toxic hazard Unpacking Controls and Connectors Installation Alignment Specifications How to contact Eddystone Broadcast Limited Technical Section Contents Declaration of conformity No part of this manual may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying recording or information storage and retrieval systems for any purpose other than the purchaser s personal use without the express written permission of sbs Information in this document is subject to change without notice and does not represent a commitment on the part of Eddystone Broadcast Limited Eddystone Broadcast Limited shall not be liable for any direct indirect consequential or incidental damages as a result of the use or misuse of this equipment handbook or any related materials Page 2 1 Introduction The Eddystone Broadcast Limited FM10 has been designed for groups looking for low power FM transmission equipment It can include a high quality deviation limiter and stereo encoder With the addition of a low cost aerial it is all that is needed to get on air Because of the broadband design of the unit no tuning is required Frequency setting is by means of internal direct reading dial up switches Output is automatically muted during lock up time The stereo version i
4. 6 R47 6 Diod Fa 0201 IF D3o F 040 R38 R37 9 9 99 U6 D US 9 9 R39 FIL2 Io R15 R16 9 9 Page 20 10 4 LimX EIE Lpo 1 Ne ot M s vo E 5 3 E 1 A gt
5. 7 Alignment The FM10 is usually supplied ready aligned and therefore the following steps should not normally be necessary 71 Frequency setting 7 2 Output power level 73 Forward power alarm 74 Modulator input level 75 DLM3 PCB 7 6 LimX PCB When an automatic change over system is in use such as the ACU3 this should be disconnected overridden such that the FM10 operates continuously during the set up procedure 7 1 FREQUENCY SETTING Setting the frequency is a simple operation Direct reading dials are located on the PLL7 PCB For example to set a frequency of 107 30MHz set the 10MHz dial to 0 the 1MHz dial to 7 the 100 2 dial to 3 and the 12 5kHz dial to 0 For 98 35 set 10MHz dial to 9 the 1MHz dial to 8 the 100kHz dial to and the 12 5kHz dial to 4 4 x 12 5kHz 50kHz Whilst the Phase Locked Loop is Locking up the modulator output is muted indicated by the PLL LOCK LED on the PLL7 PCB When the 10 is either powered up or the frequency changed it will normally take about 5 seconds for the PLL to lock up However if the frequency is changed from a high one to one at the bottom of the band with the unit in operation it can take up to 10 seconds for the PLL to attain lock Page 9 7 2 OUTPUT POWER LEVEL A small trimmer tool or precision screwdriver will be required to adjust the output power The control is located on the rear panel The output power should be set using an accurate power meter connected to
6. Name of Manufacturer sbs Product FM10 FM Exciter Declaration The product described above compiles with the requirements of the Low Voltage Directive 73 23 EEC and the protection requirements of the EMC Directive 89 336 EEC issued by the Commission of the European Community Compliance with these directives implies conformity to the following European Standards EN 60065 1998 Safety requirements for mains operated electronic and related apparatus for household and similar general use EN 50081 2 1994 Electromagnetic compatibility Generic emission standard Industrial environment EN 50082 2 1995 Electromagnetic compatibility Generic immunity standard Industrial environment Additionally the product described above complies with all relevant parts of the following standards ETS 300 384 1995 Radio broadcasting systems Very High Frequency VHF frequency modulated sound broadcasting transmitters Signed Date of Issue On file 16 05 2001 for and on behalf Pyers Easton of sbs UK CEO Page 24
7. e injurious to health or even FATAL Extreme care must be exercised when replacing and discarding components which may contain Beryllium Oxide If any such device is physically damaged you should seek expert advice e g by contacting the device s manufacturers All such devices must be disposed of in accordance with local regulations In the UK your local council will have a toxic waste disposal department who will be able to advise you Elsewhere you should contact the responsible authorities NEVER DISPOSE OF A DEVICE CONTAINING BERYLLIUM OXIDE WITH GENERAL WASTE Page 5 4 Unpacking This package should contain 1x FM10 Series broadcast exciter transmitter 1x IEC Mains lead 1x FM10 series manual If any items are missing or damaged please inform your supplier immediately Initial Checks Ensure that the FM10 has been set to the correct mains line voltage for your country The standard version is set to 230V Page 6 5 Controls and Connectors Front Panel POWER LIMIT Rear Panel Audio input EXT MPX Loop Monitor Mains power is applied The audio input level is high enough for the limiter to reduce its level where fitted Unbalanced on female BNC connector without internal limiter or balanced on female XLR connector with optional limiter pin 2 hot 3 cold and 1 ground Multiplex output unbuffered on BNC connector switchable multiplex input on BNC connector If switch is in ON position the mu
8. gnment procedure are available on request from Eddystone Broadcast Page 10 7 5 DLM3 1 FET BIAS Connect an audio input at 400Hz to the Mono input that is below the limit threshold for example 20dBu Turn R33 fully anti clockwise Connect an oscilloscope or level meter to U3 pin 7 Turn R33 slowly clockwise until the level is reduced by 0 1dB The level will vary whilst R33 is turned 2 MODULATOR INPUT LEVEL Connect an audio input at 400Hz to the audio input such that the front panel limit LED is fully ON LINK TP1 on the DLM3 PCB to ground This disables the limiter leaving the clipper active Adjust the AUDIO LEVEL control on the PLL7 PCB to give 75kHz minus your desired Guard band of deviation A typical value would be between 55 and 65 kHz Disconnect the ground link from TP1 3 INPUT LEVEL Connect an audio oscillator to the audio input Set its output to 400Hz and the output level to the desired limit threshold Turn R19 fully anti clockwise Connect an oscilloscope to the MPX OUTPUT connector Turn R19 clockwise and observe that the peak level shown on the oscilloscope increases Stop adjusting R19 at the point where the peak level stops increasing Page 11 7 6 LimX PCB 1 FET BIAS Connect an audio input at 400Hz to the LEFT and RIGHT or mono inputs that is below the limit threshold for example 20dBu Turn R40 and R31 fully anti clockwise Connect an oscilloscope or level meter to U7 pin 7 Turn R31 slowly cl
9. is formed by coil L1 and varicap diodes VD1 and VD2 together with capacitors C17 C20 These components are used as part of a cascode oscillator whose output is then buffered by transistor T3 The RF output from T3 is impedance matched to the base of transistor T5 by RFT1 a 4 to 1 matching transformer The high power output from T5 is impedance matched by coils L2 and L3 and associated capacitors to the 50 ohm output socket CON2 These components also provide harmonic filtering The PLL circuit is primarily IC2 which is a serially programmable PLL chip The microcontroller IC3 reads the dial switches at switch on and outputs a serial code to the PLL chip in a format that determines the output frequency that the PLL will try and lock the transmitter to The PLL chip outputs control pulses to the loop filter built around op amp 4 The loop filter takes the sharp pulses from the PLL chip and converts them into a smoothed signal ready to apply to the frequency determining components varicap diodes VD1 and VD2 IC1 is an analogue switch that shorts out two of the resistors in the loop filter which enables the transmitter to get on frequency faster When the oscillator is on frequency the Analogue switch switches out which greatly improves the audio response of the transmitter The microcontroller IC3 determines when to switch the analogue switch in and out by reading the lock detect signals from the PLL chip The microcontroller can also use this informa
10. isconnect the audio input Switch the pilot on Adjust R86 to give a deviation of 6 75kHz In any of the above cases if an RDS SCA unit is to be connected the output level of it may need re calibration Page 12 8 Specifications Frequency range 87 5 to 108 MHz in 50kHz steps Frequency stability lt 200Hz Power output 1 10W Harmonic amp spurious output lt 76dBc AM noise 50 wrt 100 Nominal input level OdBu or 8dBu adjustable Input Electronically balanced with limiter or unbalanced Input impedance 20 CMRR 54dB typ Pre emphasis 50uS AF response with pre emphasis lt 0 5dB 50 2 15 2 THD lt 0 15 at 75kHz Power supply 230Vac 10 Power consumption lt 40 Dimensions 1Ux260mm Page 13 9 How to contact Eddystone Broadcast Limited For all enquiries write to Eddystone Broadcast Limited 26 Arden Road Arden Forest Industrial Estate Alcester Warwickshire B49 6EP Or telephone 01789 762278 within the UK 44 1789 762278 from outside the UK Or fax 01789 766033 within the UK 44 1789 766033 from outside the UK Or email sales eddystone broadcast com Alternatively visit our web site http www eddystone broadcast com Page 14 10 10 1 10 2 10 3 10 4 10 5 Technical Section Contents PLL7 Modulator PCB PSU15 Power Supply PCB DLM3 Limiter PCB FM10 M only LimX Stereo coder FM10 S only FM10 PA 10W Power amplifier Page 15 10 1 PLL7 The frequency determining element
11. ltiplex is disconnected internally If switch is in OFF position the external multiplex input is disabled and the multiplex signal is connected internally 25 way female D type Pin 1 Power supply OK Pin 2 Forward power OK Pin 4 Mute RF output Pin 5 24 reserved Pin 25 Ground The power supply OK and forward power OK outputs are open collector and are normally low ON in the normal condition The Mute input should be grounded to mute the output This connector is not normally fitted on cable distribution versions O P Monitor RF Out Monitor of RF output approx 40dBc This output should not be used to measure harmonic spurious levels 500 N type female connector Power Multi turn power control Mains Filtered IEC male connector with T1A fuse in pull out drawer Page 7 6 Installation The FM10 is normally supplied ready aligned therefore installation should be straight forward Before installation please read the section of this manual about Electrical safety RF leads should be made from high quality low loss cable and connectors of the correct impedance using the manufacturers recommended termination techniques Since connectors are a source of unreliability in any system the number of terminations in any RF lead should be kept to a minimum All other cables for audio and control signals should be high quality screened types For XLR connectors the screen should be connected to the connector body Page 8
12. ockwise until the level is reduced by 0 1dB The level will vary whilst R31 is turned Connect the oscilloscope level meter to U6 pin 7 Turn R40 slowly clockwise until the level is reduced by 0 1dB The level will vary whilst R40 is turned 2 MODULATOR INPUT LEVEL Connect an audio oscillator level 8dBu at 1kHz to the MPX IN socket and turn the EXT MPX LOOP switch on right position Using a deviation meter adjust the AUDIO LEVEL control on the PLL7 PCB to give 75kHz deviation Return the EXT MPX LOOP switch to the OFF position left 3 LimX OUTPUT LEVEL Connect an audio input at 400Hz to the LEFT and RIGHT audio inputs such that the front panel limit LED is fully ON LINK TP1 on the LimX PCB to ground This disables the limiters leaving the clippers active Switch the pilot off Adjust R1 to give 75kHz minus 6 75kHz minus your desired Guard band deviation A typical value would be between 50 and 60 kHz Disconnect the ground link from TP1 4 INPUT LEVEL Switch the pilot off Connect an audio oscillator to the left and right inputs Set its output to 400Hz and the output level to the desired limit threshold Turn R15 and R3 fully anti clockwise Connect an oscilloscope to the MPX OUTPUT connector Turn R15 clockwise and observe that the peak level shown on the oscilloscope increases Stop adjusting R3 at the point where the peak level stops increasing Now adjust R15 clockwise until the waveform is a pure sine wave 5 PILOT LEVEL D
13. s available with its own high quality deviation limiter and coder This can be offered as an upgrade for the mono FM10 The unit will operate into any SWR without damage with an effective VSWR protection circuit which reduces the output power if necessary to protect the amplifier Page 3 2 Safety Electrical hazard This unit contains high voltages which could fatal YOU MUST ALWAYS ISOLATE THE UNIT FROM THE MAINS SUPPLY BY COMPLETELY DISCONNECTING IT BEFORE ATTEMPTING TO OPEN THE CASE THIS EQUIPMENT MUST BE EARTHED Do not expose this equipment to rain or any other source of moisture In common with all mains operated equipment only suitably trained competent personnel should attempt to adjust modify or repair this equipment or operate it with the cover removed In case of query please contact your local agent or Eddystone Broadcast Limited Any unauthorised adjustment modification or repair of this equipment may invalidate any warranty and or safety approvals that apply Please read all of this manual and familiarise yourself with the controls before attempting to use this equipment To ensure safety it is the responsibility of the user to install and operate this equipment in a manner that is within the manufacturers specifications Page 4 3 Safety hazard This equipment includes devices which contain Beryllium Oxide which is a highly toxic substance Inhalation or ingestion of even tiny particles could b
14. the RF output which in turn should be connected to an adequately rated dummy load Ifa dummy load is not available then the FM10 could be set up connected to the aerial this case the Output Power control should be set to minimum anti clockwise before powering up the FM10 7 3 FORWARD POWER ALARM This setting defines the point at which a forward power fault is indicated at the Control Monitor socket for telemetry and or operation of an automatic change over system This is not adjustable on the FM10 It is pre set to about 3W 7 4 MODULATOR INPUT LEVEL The setting of the modulator AUDIO LEVEL control on the PLL7 PCB will depend on the version supplied For the FM10 M please read the section below headed DLM3 PCB and for the FM10 S please read the section headed LimX PCB An accurate deviation meter will be required which should be connected to the rear panel RF monitor socket or output on the cable distribution version version no limiter or stereo encoder The FM10 is normally supplied with the modulator input level set so that an input level of 8dBu over the range 5Hz to 100kHz without pre emphasis gives a deviation of 75kHz If a different level is required then it will be necessary to reset the AUDIO LEVEL control on the PLL7 board Apply a 400 2 sine wave at the level required for maximum deviation normally 75kHz Adjust the AUDIO LEVEL control to give the required deviation Full details of the ali
15. tion to switch off transistor T3 with open collector configured T4 which mutes the RF output when the transmitter is out of lock LED1 provides visual indication of the PLL locked condition The master clock oscillator OSC1 determines the accuracy of the output frequency It is a high stability temperature compensated crystal oscillator TCXO The frequency can be trimmed if required by adjusting the small trimmer located beneath a hole in the oscillator module Audio is fed into the modulation input connector CON2 From here the signal passes to variable resistor VR2 where modulation levels can be set it is then passed via R29 to the varicap diodes Page 16 H i d w __ 17 10 2 PSU15 amp iba EIS 49ef 6 621 1661 580 158 2 g enss umeug 19 138 ZQ S162 231 921411 ALe ZA 18128 70055 gt ER ng aes N rf ino 20 gt lt 12 2 08129 12 01 gt amp
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