Toa WTU-870, WTU-871 Instruction Manual

Instruction Manual

WIRELESS TUNER MODULE

WTU-870
WTU-871

GENERAL DESCRIPTION

The WTU-870 (WTU-871) is a wireless tuner module for TOA's VHF high band diversity
tuner model WT-870. To ensure its reliability, it employs a compressor/expander system

noise reduction circuit to minimize the influence of high-frequency noise generated from
digital equipment such as personal computers and word processors, as well as a
combined noise/tone squelch circuit.

SPECIFICATIONS

Power supply : 10V DC
Current consumption : 130 mA (max.)
Receiving frequency : 169.445 MHz-171.905 MHz (FCC Part 90/USA)

174.250 MHz-215.250 MHz (FCC Part 74AJSA, DOC/CANADA)

173.8 MHz-175.0 MHz (MPT 1345/UK)

202.1 MHz-203.7 MHz (DOC 60/AUSTRALIA)

Receiving circuit: Single superheterodyne circuit
Antenna input impedance : 75 ohms, unbalanced

Receiving sensitivity : Under 20 dBµV (S/N : 75 dB/Deviation : 15 kHz)

(S/N : 80 dB/Deviation : 40 kHz)

Squelch sensitivity : 14 dBuV

Maximum deviation : 15 kHz (FCC Part 90/USA, DOC/CANADA, DOC 60/AUSTRALIA)

40 kHz (FCC Part 74/USA, MPT 1345/UK)

Dynamic range (SNR): Better than 90 dB (102 dB: A-weight)(60 dBµV, 15 kHz Deviation)

: Better than 95 dB (102 dB : A-weight)(60 dBµV, 40 kHz Deviation)

Residual noise: Less than 30 µ V (8 µV: A-weight)
Output level: 0 dBV (Maximum deviation, 2.2k ohms load)
Distortion : Less than 1 %
Temperature range : -10 °C~50 °C (14 °F~122 °F)
Dimensions : 60 x 25 x 139 mm (2.36" x 0.98" x 5.47")

Weight: 155g (0.34 Ib.)

Standard accessory

Frequency label: 1

* Specifications are subject to change without notice.

TOA Corporation

Function of card edge pins

No.1 : RF input B

No.2: Ground

No.3: AF output

No.4: Ground

No.5 : Squelch output B

No.6 : Squelch output A

No.7: Ground

No.8: +B power input (10V)

No.9: Ground

No.10: RF input A

Note: (1) Refer to the diversity tuner's operating instructions for installation and operation

of the tuner module.

(2) Be sure to refer the module installation to authorized service personnel.

TOA Corporation

KOBE, JAPAN

133-07-069-90