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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 - 9242 2900, Fax 618 - 9242 3900
TA-90
Automatic Antenna Tuner for Vehicle Whip
First Edition
Print date: December 1997
Author: Rod Macduff
Literature Reference Number: TECH04.PUB
Part Number: QM1021
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Summary of Contents for Q-Mac TA-90
- Page 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.
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Page 2: Table Of Contents
TABLE OF CONTENTS Section 1 Introduction ...................... 2 Section 2 Product specification ..................3 Section 3 Mechanical assembly ..................4 Section 4 Functional overview ..................5 Section 5 Block diagram ....................7 Section 6 Circuit description and Schematic Diagrams ........9 Section 7 Fault finding .................... -
Page 3: Introduction
Road visibility is not impaired by the tuner when fitted to a vehicle. The TA-90 is versatile. It can be used on trucks, buses, small vessels and aircraft or helicopters (24volt version). Wire antennas may be used. - Page 4 Tuner with mounting plate:- 242 (L) x 206 (W) x 59 (D) Whip Antenna:- 1.8m (L) Whip antenna with spring and insulator:- 2m (L) Weight:- TA-90 tuner box on plate 2.2kg. Antenna mounting:- 1/2” BSW screw Environment rating:- IP67 (fully waterproof, limited immersion).
- Page 5 All connectors are protected by a heavy duty aluminium plate (stone guard) which has mounting holes for U-clamp fixing to bull-bars. The TA-90 can be mounted in any orientation but is best configured with the connectors to the side and with the antenna feed topmost (see installation guide).
- Page 6 4. FUNCTIONAL OVERVIEW The function of the TA-90 autotuner is to allow maximum power transfer between a Q-MAC HF-90 transceiver and the 1.8m helical whip or a wire antenna. The 1.8m continuously loaded whip when mounted on a vehicle has an equivalent circuit as shown in Figure 1.
- Page 7 On the HF-90 transceiver when the TUNE button is pressed or on the first occasion when PTT is pushed on a new channel, the +12volt auxiliary supply to the TA-90 is interrupted for 400ms. Following this, a CW signal of three seconds duration is produced at approximately 20watt power level.
- Page 8 5. BLOCK DIAGRAM The RF chassis of the TA-90 auto-tuner comprises a selectable 2:1 matching transformer or 47pF series capacitor, a selectable impedance matching receive preamplifier, a series of fifteen binary weighted relay switched toroidal inductors and a current sensing transformer at the antenna output.
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Page 10: Circuit Description And Schematic Diagrams
DIAGRAMS RF Section The RF section of the TA-90 comprises fifteen separate relay switched toroidal inductors. These inductors are approximately binary weighted. This means that up to 2 ↑ 15 inductance combinations are possible with a minimum inductance of 144nH and a maximum inductance of 100µH. - Page 12 Microprocessor Section In the TA-90, tuning is controlled by a microprocessor U1. This microprocessor executes a program stored in EPROM U2 which is addressed via latch U3. Antenna current is monitored via the optical link resulting in a voltage in range 0-5volt on the collector of phototransistor Q1.
- Page 14 MICROPROCESSOR I/0 DEFINITION PORT 0 Address/Data Multiplexed Bus. PORT 1 Inductor Relay Switching Outputs. High = inductor selected. P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 PORT 3 Inductor Relay Switching Outputs. High = inductor selected. Plus A/D comparator Input on MSB. P3.0 P3.1 P3.2...
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Page 15: Fault Finding
Check that RF power is being delivered to PL259 connector in range 10-30watt when TUNE is pressed. Disconnect and reconnect DC power feed to TA-90. Two phases of relay activity should be heard. If this is not heard then proceed to step 6. -
Page 16: Hints And Tips
Earlier versions of the HF-90 prior to Serial Number 1700 had the +12volt switched power to the TA-90 fed via a 2w 1R resistor. This should be replaced with a yellow Polyswitch which has a lower resistance at normal operating current. -
Page 17: Parts List
9. PARTS LIST DESCRIPTION QUANTITY DESIGNATORS 10R 1206 SMD 5% (00100) 33R 1206 SMD 5% (00330) 100R 1206 SMD 5% (00101) 330R 1206 SMD 5% (00331) 1K 1206 SMD 5% (00102) 3K3 1206 SMD 5% (00332) 10K 1206 SMD 5% (00103) 33K 1206 SMD 5% (00333) 100K 1206 SMD 5% (10104) 330K 1206 SMD 5% (00334) - Page 18 DESCRIPTION QUANTITY DESIGNATORS 330N 1206 SMD X7R (10334) 3U3 SMD TANTALUM (10335) 100U SMD ELECTRO (17107) 47P6KV CERAMIC (17470) INPUT MATCHING XFMR (37014) CURRENT TRANSFORMER (37004) 144N TOROID (37012) 256N TOROID (37011) 400N TOROID (37010) 706N TOROID (37009) 1, 1U TOROID (37008) 1, 8U TOROID (37007) 2, 58UH/24T TOROID (37019) 3, 8UH/29T TOROID (37020)
- Page 19 DESCRIPTION QUANTITY DESIGNATORS BPW85 OPTO TRANSISTOR (67021) C236 SCR (61000) SST309 JFET (60200) N80C31 MICRO (76031) 27C64 EPROM (77064) 74HC14D INVERTER (73014) 74HC574DW LATCH (73574) 74HC4040D COUNTER (73040) DAC0800M DAC (78800) ULN2003L DARLINGTON (72003) LM339M COMPARATOR (70339) MC78L05ACD REGULATOR (79805) - 18 -...
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Page 20: Pcb Overlays
10. PCB OVERLAYS - 1 -...