1. INTRODUCTION
The TA-90 Automatic Tuning Antenna System is designed specifically for use with the Q-
MAC HF-90 Transceiver allowing it to deliver maximum power to a range of short whip or
wire antennas. It is optimised for electrically short antennas and is normally used in vehicle
installations with the Q-MAC QM7131 continuously loaded 1.8 metre whip.
The HF-90 is significantly different from other Autotune Antenna Systems in the following
respects.
1
The TA-90 allows a variety of mounting configurations as the antenna and tuner are
separate. On a vehicle the tuner can be mounted behind the bull-bar affording
considerable protection.
2
The system is more economic to repair in the event of a vehicle rollover or antenna
decapitation as the whip is relatively inexpensive and readily available.
3
Road visibility is not impaired by the tuner when fitted to a vehicle.
4
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.
5
Efficiency is comparatively good when operating into short whips on low frequencies.
Other autotuners are either unable to tune for these conditions or achieve poor
efficiency. Improved efficiency is due to the special low-capacitance switching
design.
6
Antenna current and power transfer to the antenna are maximised. This ensures the
best radiation efficiency when compared to VSWR based tuning systems.
7
The design uses Surface Mount Technology on a single PCB with toroidal inductors.
This ensures maximum reliability in a compact unit. It also minimises cost.
8
The TA-90 autotuner box mounted on the stoneguard plate weighs only 2.2 kg.
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