Note
The Alinco DR-235 is a rugged, monoband FM mobile transceiver designed specifically for the 1.25-meter (222 MHz) amateur radio band. Part of Alinco's popular monoband mobile series, it shares its compact chassis, user interface, and layout with its sibling rigs (the 2-meter DR-135 and 70-centimeter DR-435).
There are two versions of the unit:
– DR-235T: The original standard North American market release.
– DR-235MkIII: The updated iteration featuring minor component updates, improved frequency stability, and optimized firmware while retaining the exact same exterior controls and layout.
Features
Memory Channels: 100 fully programmable memory channels, plus 1 call channel and 1 search-pass channel. Memories store frequency, shift direction, offset, tone settings, and alphanumeric channel tags.
CTCSS & DCS: Built-in encoder and decoder for 39 CTCSS tones and 104 DCS digital squelch codes as standard equipment.
Tone Burst: Supports standard European tone-burst frequencies (1750, 2100, 1000, and 1450 Hz) for repeater access.
DTMF Squelch: Features an automatic dialer, Code Squelch, and Paging functions using 3-digit DTMF codes.
Display: A large, backlit LCD panel featuring a 7-digit alphanumeric display for custom naming of channels. It includes an integrated digital S-meter and RF output indicator.
Live Voltage Display: The display features a built-in digital voltmeter that monitors the incoming supply voltage between 7V and 16VDC, flashing an alert if the voltage falls outside operational limits.
Microphone Options: Typically paired with either the EMS-53 standard microphone or the EMS-57 DTMF backlit remote-control microphone, which allows direct frequency entry and VFO/memory manipulation.
Ignition Key On/Off Feature: A specialized low-current DC line can be wired directly to a vehicle's ignition switch, allowing the radio to power up and shut down automatically with the vehicle engine.
Theft Alarm: An innovative security loop feature that triggers an audible alarm and flashes the display if the radio is disconnected from its mounting bracket installation.
Specifications
Specifications
– Frequency Coverage:
Transmit: 222.000 – 224.995 MHz
Receive: 216.000 – 279.995 MHz (includes AM aircraft band and expanded VHF reception)
– Power Output: Three selectable levels:
High: 25 Watts
Mid: 10 Watts
Low: 5 Watts
– Modulation: Variable reactance FM (F3E).
– Power Supply Requirement: 13.8 VDC (±15%) negative ground.
– Receiver Circuit Type: Double-conversion superheterodyne.
– Intermediate Frequencies (IF): 1st IF at 30.85 MHz, 2nd IF at 455 kHz.
– Sensitivity: Better than -12.0 dBu (0.25 uV) at 12 dB SINAD.
– Audio Output: A robust 2.0 Watts minimum into an 8-ohm load at 10% distortion, making it well-suited for high-ambient-noise environments like mobile vehicle cabins.
– Memory Channels: 100 fully alphanumeric channels, plus 1 call channel.
– Modulation: FM (and AM receive capable for certain frequencies).
– Frequency step: 5, 8.33, 10, 12.5, 15, 20, 25, 30, 50 kHz
– Memory channel: 100 channels + 1 call channel
– Antenna impedance: 50 Ω unbalanced
– Frequency stability: ±2.5 ppm
– Operating temperature: -10 °C to +60 °C (+14 °F to +140 °F)
– Modulation system: Variable reactance frequency modulation
– Max. frequency deviation: ±5 kHz
– Spurious emission: -60 dB or less
– Microphone impedance: 2 kΩ
Receive system: Double-conversion superheterodyne
Intermediate frequencies: 1st 30.85 MHz, 2nd 455 kHz
Sensitivity (12dB SINAD): -12.0 dBu (0.25 µV) or better
Squelch sensitivity: -16.0 dBu (0.16 µV) or less
Selectivity: -6 dB: 12 kHz or more, -60 dB: 28 kHz or less
Audio output power: 2.0 W (8 Ω, 10% distortion)
Supply voltage: 13.8 VDC ±15% (11.7-15.8 V)
Current
TX High: 25W, approx. 8.0 A
RX: Squelched approx. 0.4 A
Max audio approx. 0.6 A
Data & Expansion Options
– 9600 bps Packet Ready: Features a dedicated data jack on the rear panel supporting both 1200 bps and 9600 bps packet radio modems.
Internal Slot for Digital Operations: The radio includes a dedicated internal compartment to accept optional accessory boards:
– EJ-41U TNC Board: For internal, hardware-level AX.25 packet operations.
– EJ-47U Digital Voice Board: For legacy digital voice modulation schemes.
