TX Techniques TX FM1 Technical Manual Download Page 6

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TX-FM1/S/R/A Technical Manual                                            www.txtechniques.co.uk

2. Safety Information

2.1 General Safety Information

Use of this device into a radiating antenna requires a valid Wireless and Telegraphy
licence.

Never operate this device without a suitable 50 ohm load connected to the RF
OUTPUT socket, or without a suitable antenna.

Use of this device as part of a transmission system, or combined transmission
system not specified by the manufacturer, may require further testing to ensure that it
remains compliant with the essential requirements and other relevant provisions of
Directive 19999/5/EC. Approval from a 'Notified Body' and clearance from the
Spectrum Management Authority may also be required.

Never allow audio, or audio peaks, in excess of +8dB enter the AUDIO IN LEFT
and/or AUDIO IN RIGHT input sockets, as this may lead to overmodulation of the
carrier. Always use an external audio limiter in cases where audio levels may exceed
+6dBu. FAILURE TO COMPLY MAY INVALIDATE ANY WARRANTIES OR
APPROVALS GIVEN TO THIS PRODUCT.

RISK OF FIRE!  High power RF (Radio Frequency) energy could cause ignition of
combustible surfaces during fault conditions. Installation should be left to qualified
personnel. RF can cause severe burns to skin. Ensure antenna systems and feeder
cables are not situated near – or could fall onto – any combustible surface.

Installation must adhere to safety regulations and the requirements of the relevant
authorities. We recommend that at least two people are present during installation.
Keep a file containing installation instructions and plans, including details of the
transmission system (antennae, feeders, filters, etc) and operating instructions for all
equipment at the transmission site at all times. Display posters detailing first aid
treatment and treatment for electrical shock, along with telephone numbers for
contacting the emergency services in the event of personal injury.

BERYLLIUM OXIDE IS LETHAL. Some components inside this appliance contain the
highly dangerous TOXIC substance Beryllium Oxide. In case of damage contact the
manufacturer or its Agent immediately. Seek advice from the local authority when
discarding this appliance.

To reduce the risk of electrical shock, do not remove the cover, or any screws. NO
user serviceable parts inside; refer servicing to qualified personnel.

To reduce the risk of fire or electrical shock, do not expose this appliance to rain or
moisture.

To reduce the risk of fire, always replace fuses with the same type and rating.

Do not operate this appliance without a suitable 50 ohm dummy load or a suitable,
matched antenna connected to the RF OUTPUT socket on this apparatus. Although
the output devices used in this appliance are intended to be open and short circuit
tolerant, MIS-OPERATION MAY RESULT IN DAMAGE NOT COVERED BY ANY
WARRANTY.

The heatsink at the rear of this appliance may become very warm under normal
operating conditions.

Summary of Contents for TX FM1

Page 1: ...for any direct indirect incidental consequential or other damage or loss alleged in connection with the supply or use of this product The information contained in this document is subject to change wi...

Page 2: ...stments 5 1 Carrier Frequency Setting 10 5 2 Carrier Frequency Fine Tuning 10 5 3 RF Output Power 10 5 4 Audio Processor Input Level 10 5 5 Audio Processor Individual Band Adjustment 10 5 6 Audio Proc...

Page 3: ...CB 16 7 5 FM1 RDS PCB 17 7 6 FM1 PA PCB 17 7 7 FM1 RF PCB 18 7 8 FM1 LCD PCB 18 8 Wiring 8 1 Wiring Diagram 19 9 Circuit Diagrams 9 1 FM1 EXCI PCB 20 9 2 FM1 ALC L PCB 21 9 3 FM1 ALC R PCB 22 9 4 FM1...

Page 4: ...zero ohm links Every connection to every PCB is pluggable allowing fast serving The use of through hole components means components can be replaced easily by engineers using traditional methods The TX...

Page 5: ...level sounds and noise Multiple peak limiting stages provide the control needed to ensure that final clipping circuitry operates with negligible distortion or audible effect across all kinds of progr...

Page 6: ...st adhere to safety regulations and the requirements of the relevant authorities We recommend that at least two people are present during installation Keep a file containing installation instructions...

Page 7: ...n of the rear heatsink which can be impeded if the unit is placed on a flat surface The transmitter should be situated away from heat sources The transmitter should be connected to a power supply only...

Page 8: ...s been spilled into it or The transmitter has been exposed to rain or The transmitter does not appear to operate normally or exhibits a marked change in performance or The transmitter has been dropped...

Page 9: ...electing RF provides monitoring of forward RF FWD and reflected RF REF power measurements AF provides a graphical PPM meter showing the sum of the LEFT and RIGHT audio inputs Please note that this is...

Page 10: ...selected on the internal frequency setting switches the unit will not initialise Instead it will display ALARM SYSTEM ERROR after a short while Disconnect the mains supply select a valid frequency int...

Page 11: ...en if it is not evident when previewed without audio processing Also CD recordings mastered at very high levels often drive many CD players reproduction circuitry into clipping distortion If after ens...

Page 12: ...been activated the RDS OFF tones are not received within 4 minutes the TX FM1 S R A will automatically cancel the TA mode Abuse of this system may incur penalties from the broadcasting Authorities It...

Page 13: ...right audio channel and R32 left audio channel on the FM1 ALC board determines the overall level entering the multiband audio processor Decrease Normal Increase 1K5 min 2K2 4K7 max Use of values othe...

Page 14: ...ting VR4 on the FM1 RDS PCB This setting requires the use of a modulation monitor connected to the front panel AF monitor BNC socket 5 12 MPX Subcarrier Null The DSSC generation of the stereo multiple...

Page 15: ...d and presented to the LCD meter and the DTMF TA controller as a mono source via socket PL5 The audio passes through IC3 A the gain of which is controlled by OR1 in its feedback path The output of IC4...

Page 16: ...has the effect of maintaining a constant modulation level across the entire FM band TR2 and TR3 form a Cascode oscillator which is buffered by TR4 and switched by TR5 This allows the exciter output to...

Page 17: ...and SW2 6 7 RF Amplifier The RF amplifier design uses a Motorola RF MOSFET device C1 L1 C2 and L2 form an input matching circuit ZD1 rectifies the RF forming a bias for TR1 and R1 in conjunction with...

Page 18: ...R SWITCHING ACTIVE START CIRCUIT RECTIFIERS FILTER LIMITING DETECTION CIRCUIT PWM PFC CONTROL O V P O T P O L P 24Vdc 24Vdc 24Vdc 5Vdc 12Vdc VFO PLL uPC BCD FREQUENCY SELECT SWITCHES FILTER AND ERROR...

Page 19: ...CTIFIERS PRECISION RECTIFIERS AF IN AF OUT AF OUT AF IN DTMF DETECTOR FRONT PANEL METER AUDIO RC LOWPASS FILTER COMPRESSOR LIMITER COMPRESSOR LIMITER FINAL CLIPPER 15kHz LOW PASS FILTER COMPRESSOR LIM...

Page 20: ...LF BIAS OUTPUT MATCHING NETWORK MASTER CLOCK SOURCE uPC DIVIDE BY 8 12 24 uPC DATA SINE SYNTHESIS SUPPRESSED CARRIER MODULATOR MATRIX AMPLIFIER SUPPRESSED CARRIER MODULATOR SQUARE WAVE TO SINE WAVE FI...

Page 21: ...hnical Manual www txtechniques co uk 7 7 FM1 RF PCB 7 8 FM1 LCD PCB AUDIO MPX INHIBIT FWD RF INHIBIT SOUNDER REF RDS TP INHIBIT LCD DISPLAY uPC A D CONVERTOR ROTARY ENCODER FWD REF POWER MEASUREMENT R...

Page 22: ...19 TX FM1 S R A Technical Manual www txtechniques co uk 8 Wiring Diagram REF FWD...

Page 23: ...9 Circuit Diagrams 9 1 FM1 EXCI...

Page 24: ...9 2 FM1 ALC Left Audio Channel...

Page 25: ...9 3 FM1 ALC Right Audio Channel...

Page 26: ...9 4 FM1 AP...

Page 27: ...9 5 FM1 RDS...

Page 28: ...9 6 FM1 PA...

Page 29: ...9 7 FM1 RF...

Page 30: ...9 8 FM1 LCD...

Page 31: ...LVD 73 23 EEC EN60215 and amendments where applicable EMC Directive 89 336 EEC EN55022 Class 2 EN61000 4 2 EN61000 4 3 EN61000 4 4 EN61000 4 5 EN61000 4 6 EN61000 4 11 R TTE Conformity was assessed vi...

Page 32: ...tereo Encoder Separation Better than 42dB Subcarrier null Better than 50dB Pilot stability 2Hz typical RDS Encoder Blocks handled 0B 2A Features PI PTY AF PS RadioTEXT TP TA TA remote switching DTMF t...

Page 33: ...techniques co uk 30 We reserve the right to alter specifications without notice TX Techniques Ltd Unit 25 Claro Court Business Centre Claro Road Harrogate HG1 4BA Tel 44 0 1423 565394 Fax 44 0 1423 52...

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