Qmac_HF-90_serv.pdf

- 1 - No part of this manual may be copied, transcribed, translated or reproduced in any manner or form whatsoever, for commercial purposes, without obtaining prior written permission from Q-MAC Electronics Pty Ltd. However, limited copying is permitted for private use providing authorship is acknowledged. Copyright Q-MAC Electronics Pty Ltd, 2003. 142 Hasler Road Osborne Park, WA 6017 PO Box 1334 Osborne Park Business Centre, WA 6916 AUSTRALIA Australia: Phone 08 - 9242 2900, Fax 08 - 9242 3900 International: Phone +618 - 92242 2900, Fax +618 - 9242 3900 First Edition Print date: August 1996 Second Edition Print date: February 1997 Third Edition Print date: October 2000 Author: Rod Macduff Literature Reference Number: TECH02C.PUB Part Number: QM1021 Additional Technical Support: Note that additional technical support is available to Q-MAC Dealers under the “Dealer Support” section of the Q-MAC website: . This site incorporates Technical Bulletins issued by Q-MAC, plus Technical Notes and Instructions in relation to specific products. - 2 - TABLE OF CONTENTS Section 1 Warnings & advice.4 Section 2 Introduction. 5 Section 3 Product specification. 6 Section 4 Mechanical assembly.7 Section 5 Functional overview.8 Section 6 Block diagrams Front panel.10 Microprocessor.11 Receiver/exciter.12 Synthesizers.13 Power amp & switching P.S.U.14 Section 7 Circuit description 7.1 Front panel PCB .15 7.2 RXMP PCB .16 7.3 PASW PCB .21 Section 8 Tables & diagrams Table 1. HF-90 micro port allocations.24 Diagram 1. Serial link chain .25 Table 2. Diagram 2. Superhet. mixing scheme.26 Diagram 3. HF-90 Rx gain distribution.26 Table 3. HF-90 Tx low pass filters.27 Table 4. HF-90 connector pinouts.28 Diagram 4. Connector positions.30 Section 9 Maintenance 9.1 Disassembly & assembly.31 9.2 Replacement of Microprocessor.32 9.3 Radio alignment.33 Section 10 Fault finding 10.1 No tools fault finding.36 Section 11 Diagnostic test sequence 11.1 Receiver test sequence.39 11.2 Transmitter test sequence .43 - 3 - Section 12 Test point overlays 12.1 RXMP test point voltages.45 HF-90 P.A. board alignment - position reference.46 Section 13 Software overview 13.1 Program description.47 13.2 Routine description (not frequency hopping).48 13.3 Software releases.50 Section 14 Hints & tips 14.1 Device removal.51 14.2 Servicing warnings.52 14.3 Servicing case histories.53 Section 15 Parts List 15.1 Front panel PCB parts list (ISSUE N).60 15.2 RXMP PCB parts list (ISSUE V).61 15.3 PASW PCB parts list (ISSUE Q) .67 Section 16 PCB overlays Front panel top overlay - issue N (designators).72 Front panel top overlay - issue N (component values).73 RXMP top overlay - issue V (designators).74 RXMP top overlay - issue V (component values).75 PASW top overlay - issue Q (designators).76 PASW top overlay - issue Q (component values).77 Section 17 Schematic diagrams HF-90 display (90000).79 HF-90 I.F. strip, micro section & synth (90003).80 HF-90 P.A. & power supply (90002).81 Section 18 External connectors.82 Section 19 Device pinouts & codes Device pinouts.84 19.1 SMD capacitor codes.85 - 4 - 1. On no account should the unit be connected directly to 110volt or 240volt AC mains power. Serious damage or personal injury may result. 2. An approved 12volt or 24volt power supply or battery should be used. The supply should be capable of sourcing peak currents up to 10ampere. Failure to comply with this rating will result in severe distortion on transmissions. Please note that some power supplies labeled as 10ampere peak are not adequate as the voltage collapses towards the peaks. 3. Use only the approved power cable for installation. Use of thinner conductors or extensions will result in severe distortion on transmissions. 4. The system performance is generally only as good as the antenna and ground system will allow. If unbalanced antennas are being used eg. whips, end-fed broadbands etc, then it is vital to obtain a good low impedance ground connection either to a vehicle body, a moist patch of ground or a metal fence with rust removed at the point of connection. 5. The HF-90 is extremely small. When transmitting, the heatsink and extrusion may get very hot. Under some circumstances it may be possible to get burned by touching the heatsink. The radio has been designed and tested to cope with elevated temperatures. However the user should endeavour to allow free circulation of air around the radio. 6. In order to achieve the high output power, an internal power convertor is used to supply +55volt to the final amplifier on transmit. The energy stored by this supply is quite high (2.2joules) and it is wise to WAIT FOR A FULL MINUTE after transmitting prior to doing any service work on the PASW printed circuit board. 7. Radio Frequency Field Exposure: The HF-90 Packages generate high radio frequency fields. Their antennas are marked with a safe working distance in accordance with required Standards. This should be observed. 8. This device complies with Part 90 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. 1. WARNINGS & ADVICE ! ! - 5 - 2. INTRODUCTION The HF-90 Compact Transceiver breaks new ground in the following areas: Size: The volume of the transceiver is approximately one litre. This is less than a tenth of comparable products. On initial inspection it is often mistaken for a VHF/UHF set. Weight: At 1 kilogram, the HF-90 is a quarter of the weight of products with a similar specification. Ease of use: The HF-90 has quite deliberately been kept simple so that persons unfamiliar with HF communications may immediately pick it up and use it. Low cost: The transceiver has been designed using state of the art SMD technology. Components from cellular telephony, satellite television, and personal computers have been used wherever possible to keep the cost at a minimum. Also, wherever possible, functionality has been implemented in software rather than hardware. Ruggedness: Use of a heavily ribbed aluminium extrusion confers great strength to the HF-90. Stainless steel handles protect all front panel controls. A ribbed rear heatsink protects the rear connectors. Reliability: Use of SMD technology and the delegation of functionality to software has led to simplicity of design which translates to high reliability. Unreliable parts such as potentiometers and wiring looms are avoided. All internal connectors have gold to gold mating surfaces. Serviceability: The HF-90 was designed with serviceability as a top priority. The radio consists of three PCBs, all of which plug together. Only four screws need be removed to access the main PCBs. These PCBs plug together as a sandwich with all the essential components and nodes easily probeable while the radio is operating, without the use of extenders. All power transistors are easily accessed and use single screw fixing. Minimised inventory: The design of the HF-90 was implemented with the minimum number of different types of components. Thus spares inventory is reduced. Versatility: The high performance and small size allows the HF-90 to be used in portable, mobile or fixed configurations. The wide power supply range (12 to 24volt) makes it particularly attractive in multi-role applications. Receiver performance: Excellent receive sensitivity is combined with a large dynamic range through the use of four GaAs FETs in the front end mixer. Transmitter performance: A very high power to weight ratio and extreme RF ruggedness is obtained through the use of 500volt MOS FETs in the power amplifier. Selcall performance: A sophisticated digital signal processing algorithm is capable of extracting very weak calls in the presence of noise. Successful decodes at down to -132dBm have been observed. - 6 - 3. PRODUCT SPECIFICATION Specifications are subject to change without notice General Frequency range: 2 ! 30MHz Modes of operation: USB, LSB (J3E) CW (optional) Hopping (optional) AM (Rx only), FSK Number of channels: 255 Channel resolution: 100Hz Supply voltage: 12 ! 24V DC nominal Power consumption: - Transmit: 2A! 10A (subject to pre-set power output) - Receive: 310mA Frequency stability: 1.5ppm Antenna impedance: 50 Antenna connector: BNC Handsets: Speaker microphone DTMF microphone & telephone handset Selcall system: Based on CCIR 493-4 (Australian Standard) Programming: IBM PC 4800,8,1,N BITE: Micro, Rx, Tx tests Environmental Operating temperature: -30C ! 60C Storage temperature: -30C ! 80C Humidity: 95% non-condensing Environmental rating: IP54 Physical characteristics Dimensions (mm): 112(W) x 47(H) x 220(D) Weight: 1kg (HF-90 only) Construction: All metal extruded sleeve with front panel and heatsink Finish: Black anodized aluminium Transmitter Power output: 50Watt PEP Duty cycle: Normal speech or data (with fan option) Unwanted sideband: Better than -45dB Carrier suppression: Better than -50dB Harmonic suppression: Better than 60dB Spurious emissions: Better than 60dB Noise suppression: Better than -35dB Distortion: Less than 5% 70% PEP Audio response: 270Hz ! 2800Hz Microphone: Electret insert Tune: 20W radiated +1000Hz Load protection: ALC Receiver Sensitivity: 0.25V for 10dB S+N/N Selectivity: 2.3 kHz -6dB 6kHz -60dB Image rejection: Better than -50dB Intermodulation: Better than -70dB 3rd order intercept: +20dBm (GaAs FET mixer) Blocking: Better than -70dB Spurious response: Better than -60dB IF rejection: Better than -60dB Intermediate freqs: 83.16MHz, 455kHz AGC: Less than 3dB from 3V ! 1V Clarifier range: 250Hz Audio response: 270Hz ! 2800Hz Audio output: 2Watt Audio load impedance: 8 Audio distortion: Less than 5% 1W - 7 - Radio construction The radio shell comprises a 2.5mm aluminium front plate complete with black stainless steel handles, a 160mm long key-ribbed sleeve extrusion and a 10-fin extruded rear heatsink. This provides a simple and strong housing for the radio. Four M3x12 screws are used to secure both front and rear panels. The display PCB is secured to the metal front-plate by the fixing nuts of three front panel parts. This allows for simple removal. The two main PCBs pug into each other as a sandwich, and the whole assembly slides into the extruded sleeve on keyways. The rear heatsink is part of the PASW board assembly. Rubber gaskets on the front and rear mating surfaces give some water resistance. Front panel The front panel allows manual control of all the radio functions. This is achieved by six elastomer keys, an incremental shaft encoder (volume) and a toggle switch for power activation. A high efficiency 6-digit 7-segment LED display indicates the channel number on receive and frequency on transmit. An 8-pole microphone socket provides all the external interface requirements for microphones, headphones, DTMF keypad, and computer interface. The front