RetiredRA4 · no.1

RA4DIO

Name: RA4DIO
Brand: 3T3R
SKU: RA4 · no.1

The first body of the line. Retired.

The first body. Retired, along with its domain. It is here because it came first, not because you can buy it.

See the catalogRetired · not for sale

RA4 · no.1

// RA4 · no.1 · prototype render · final hardware may varyv0.1

//03The device

Built like a tool. Not like a toy.

Aluminium chassis, mechanical PTT, replaceable 18650 cell, SMA antenna, e-ink status. Designed to outlive the phone in your other pocket.

chassisCNC alucell18650portUSB-Cdisplaytouch

Knurled aluminium grip, macro — knurl · grip

Rugged back plate, macro — back · rugged

USB-C port and replaceable cell hatch, macro — port · USB-C

RA4DIO — three quarter view with antenna extended

SMA antenna mount

PTT — push-to-talk

E-ink status display

USB-C · 18650

exploded · 4 callouts

CYM-H001 · rev A

Top knobs — channel and volume — top · controls

//04On-device AI

A second mind in your pocket. Off the cloud.

A small language model lives inside RA4DIO. It answers, dictates, translates, and journals — without sending a single token to a server. No account. No log file in a data center.

Ask

Hold PTT. Speak. Get an answer — even at altitude with no bars.

Dictate

Voice → text on-device. Stays on the device until you send it.

Translate

Border-grade live translation for short utterances. No SIM required.

Journal

Think out loud. RA4DIO writes it down. Encrypted at rest.

* On-device model is intentionally small. For deep reasoning, use your phone. RA4DIO is for what your phone can't do.

RA4DIO screen running its on-device AI assistant

> where am i▍

on-device · no cloud

//04Specifications

The numbers, honestly.

Radio	Semtech SX1262 · LoRa · 868 / 915 MHz
TX power	+14 dBm ERP (EU) · up to +22 dBm region-limited
Range (LOS)*	~10 km device↔device · ~15 km to elevated node
Range (urban)*	100–800 m · building dependent
Mesh	Self-healing, store-and-forward
Crypto	X25519 · AES-256-GCM · E2E
AI	On-device small language model
Battery	Replaceable 18650 · ~24h mixed use*
Charging	USB-C PD
Chassis	CNC aluminium · IP54 target
Weight	≈ 180 g

* Range and battery numbers are pre-production targets. Final certified figures will be published before the first ship date.

//06Security

Encrypted by default. Yours by design.

Keys generated on the device, never leave it. Every message is end-to-end encrypted with modern primitives. No telemetry, no account, no recovery server that could be subpoenaed.

key exchangeX25519cipherAES-256-GCMidentityon-devicetelemetrynone

//10In the box

Everything to get on air.

01
RA4DIO unit
CNC aluminium chassis · graphite finish · serialised
02
Stock SMA antenna
Tuned for 868 / 915 MHz · region-locked at firmware
03
18650 cell + USB-C cable
Replaceable lithium cell · braided 1m USB-C PD
04
Wrist lanyard
Woven · breakaway clasp
05
Field manual
Printed. Waterproof paper. Setup in under 5 minutes.
06
Founders certificate
Numbered, signed by the 3T3R Engineering team. First 500 only.

//07Compared to

Honestly.

feature	RA4DIO	Phone	Walkie-talkie	Satellite
Works without cell tower	yes	no	yes	yes
Works without internet	yes	no	yes	partial
End-to-end encrypted by default	yes	depends	no	depends
Long-range mesh	yes	no	no	no
On-device AI	yes	no	no	no
Monthly fee	no	yes	no	yes
License required	no	no	often	no

yesnopartial / often (device-dependent)depends (varies by carrier or app)

RA4DIO

Retired

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