Model

TM-281A/TM-481A

Frequency range

136-174MHz/400-430/440-480MHz

Mode

F3E(FM)

Antenna Impedance

50 ohm

Operating Temperature

-25°C---+60°C

Power Voltage

13.8V DC ±15%(11.7-15.8V)

Dimension

160*43*137mm

Weight

1.2Kg

Transmitter

Power output

High 65W

Frequency Stability

±2.5ppm

Spurious Emissions

better than -60dB

FM noise

≤-40dB

Audio distortion

≤3%

Max. Frequency Deviation

≤±5KHz(wide)    ≤±2.5KHz(narrow)

Microphone Impedance

600ohm

Receiver

Frequency Stability

±2.5ppm

Sensitivity

Better than 0.18uV(wide)/0.22uV(narrow)

Modulated bandwidth

≥ ±7KHz(wide)/3.5Khz(narrow)

Adjacent channel selectivity

≥ 60dB

Intermodulation Rejection

≥65dB

Spurious response rejection

≥65dB

Audio output power

2W or Above

Audio output Impedence

8 ohm

Key Features

65 Watt RF Output

Rugged Construction to MIL-STD 810 C/D/E/F/G  Standards

Alpha-tagged Memories

High-Quality Front Mounted Loudspeaker

Built-In CTCSS/DCS Encoder/Decoder

Replaces previous TM-271A model

General Features

Alphanumeric LCD Display

Yes

Antenna Socket

SO-239 (M-Type)

Auto Power Off

Yes

Auto Repeater Offset

Yes

Automatic Simplex Checker

Yes

Beat Shift Function

Yes

Busy Channel Lock-out

Yes

Calling Channel Function

Yes

Channel Display Mode

Yes

CTCSS Encoder/Decoder

Yes, 42 EIA Tones with Tone Scan function

DCS Encoder/Decoder

Yes, 104 Tones with Tone Scan function

Direct Frequency Entry

Yes

DTMF Encoder

Yes

DTMF Memory

Yes, 10 DTMF memories of 16 digits each

High-Quality Front Speaker

Yes

Illuminated Front Panel Keys

Yes

Key Beep On/Off

Yes

Key Lock

Yes

Loudspeaker Socket

3.5 mm

Memory Channel Lock-out

Yes

Memory Channels

201 Channels

Menu System for individual set-up

Yes

Microphone Socket

RJ-45

Monitor Function

Yes

MR-Shift

Yes

Multiple Scan Functions

Yes

PC Programmable Memories

Yes

Power-On Message

Yes

Reverse Repeater Checker

Yes

Time-Out Timer

Yes

Variable LCD Brightness with Automatic Dimmer

Yes

Wide/Narrow Band Deviation Selection

Yes

Specifications

RF Output Power (approx.) - High

65 W

RF Output Power (approx.) - Low

25 W

TX Frequency Coverage - VHF

144 to 148 MHz (136 - 174 MHz optional)

RX Frequency Coverage - VHF

136 - 174 MHz

Transmitter Modulation

Variable-Reactance modulation

Transmitter Modulation Distortion

Less than 3% (300 Hz to 3 kHz)

Transmitter Maximum Frequency Deviation - Wide

± 5 kHz

Antenna Impedance - 50 Ohm

Yes

Audio Output Power

More than 2 W (5% Distortion)

Weight

1.13 kg (approx.)

Current Drain - RX

Less than 1 A

Current Drain - TX

Less than 14 A (Hi-Power), Less than 8 A (Low-Power)

Dimensions

160 mm (W) x 43 mm (H) x 126 mm (D) - excluding projections

Frequency Step Sizes

2.5, 5, 6.25, 10, 12.5, 15, 20, 25, 30, 50 and 100 kHz

Frequency Stability

± 2.5 ppm (-20 °C to +60 °C)

Microphone Impedance

600 Ohms

Modes - F3E FM

Yes

Operating Temperature Range

-20 °C to +60 °C

Power Requirement - 13.8 V DC ± 15%

Yes

Receiver Circuitry

Double Super Heterodyne

Receiver Intermediate Frequency - 1st IF

49.95 MHz

Receiver Intermediate Frequency - 2nd IF

450 kHz

Receiver Selectivity - Narrow

More than 10 kHz at -6 dB, Less than 24 kHz at -60 dB

Receiver Selectivity - Wide

More than 12 kHz at -6 dB, Less than 30 kHz at -60 dB

Receiver Sensitivity - Narrow

Less than 0.22 µV at 12 dB SINAD

Receiver Sensitivity - Wide

Less than 0.18 µV at 12 dB SINAD

Receiver Squelch Sensitivity

Less than 0.1 µV