01
BRANDMEISTER
Choose a US master and a public talkgroup or private destination. Talk through the phone’s internet connection, use the knob for master volume, and follow calls in Last Heard with cached RadioID names and country flags.
KE5EUA / PURPOSE-BUILT FOR THE CJ1
ONE RADIO.
A WORLD
OF SIGNAL.
From your local repeater to a reflector across the planet. Voice, data, and field tools—under your command.
RF // INTERNET // DATA
ACTUAL APP. ACTUAL RADIO.
YOUR NEXT CONTACT STARTS HERE.HARDWARE FM / DMR ✳ INTERNET VOICE ✳ APRS & PACKET ✳ WINLINK ✳ SSTV ✳ MDC1200 ✳ ONE FIELD STATION
01 / BUILT TO OPERATE
A field station.
Not just a dial.
CJ1 Radio Command brings the CJ1’s hardware radio and a growing collection of amateur-radio tools into one consistent, dark interface. Turn the knob. Choose your channel. Take the station with you.
HARDWARE RF
TAP THE SCREEN TO TAKE A CLOSER LOOK ↗
THE REPEATER. THE SIMPLEX CALL. THE EVERYDAY RADIO.
Real RF.
Right at hand.
Operate the CJ1’s onboard analog radio with the information you need up front: frequency, channel name, transmit tone, power, signal strength, volume, and squelch.
- 01
Channels that follow your hand
The hardware knob selects channels in the current zone. Tap SQL to choose a squelch level, or Volume for a direct 0–15 selection.
- 02
Find the signal
Zone Scan spends 750 ms on each channel and stops on a carrier. F2 starts or stops the scan. CTCSS Scan can identify a received tone, pausing when the carrier disappears.
- 03
Stay with the radio
A foreground service and connection watchdog support background operation. Physical PTT and the optional transmit chirp work with the screen off.
HARDWARE FIRST Built around the CJ1 radio hardware. RF FM and DMR transmit/receive have been operator-tested.
02 / BEYOND THE LOCAL REPEATER
The world is
on the other end.
Open the globe menu and choose your network. A shared layout keeps destination, connection state, volume, and scrolling Last Heard in familiar places.
INTERNET VOICE / RoIP
VOICE TESTED
02
D-STAR
Link to a reflector and module, hear traffic, and transmit with physical PTT. Reflector configuration lives in Settings so the operating page stays focused.
03
YSF / SYSTEM FUSION
Connect to a YSF reflector for DN digital voice. Includes microphone and speaker audio, busy-channel protection, volume control, and its own call history.
04
P25
P25 Phase 1 voice over an internet reflector, with destination talkgroup selection, caller lookup, and Last Heard. This is RoIP voice, not hardware P25 or trunking.
05
M17
Reflector linking and Codec2 voice support, including 3200-bps transmit and compatible 1600-bps reception. Local codec and link checks passed; live voice confirmation is still pending.
06
ECHOLINK
Encrypted account settings, online station search, direct or manual-proxy connections, GSM voice, and Last Heard. Live login and voice testing await account validation; incoming calls and chat are not included yet.
ONE ACTIVE INTERNET MODE AT A TIME.
Leaving a RoIP operating page disconnects its session. Busy-channel lockout and a busy tone help prevent talking over received traffic.
03 / THERE’S MORE THAN VOICE ON THE AIR
Packets. Positions.
Pictures. Possibilities.
Turn the handset into a working data station, with the same controls and field-ready look across every page.
APRS
GPS → RFAutomatic GPS updates every five seconds feed analog APRS position reports. Choose 144.3900 or 145.8250 MHz, both configured for high power, and start or stop Smart Beaconing.
Smart Beaconing can keep running while you use a hardware voice channel: the radio waits for a clear opportunity, visits the APRS frequency, transmits, and restores the voice channel. Received APRS packets can populate a scrolling history with callsign, position, and comment.
ALSO INCLUDED A separate hardware DMR APRS page uses DMR messaging for position reporting.
PACKET RADIO
Connected AX.25 terminal sessions for BBS and node access. Use the ANALOG FM channel’s frequency and configure your callsign/SSID, remote node, and digipeater path under Packet Radio Settings.
RF SESSION VALIDATION CONTINUESWINLINK
A local mailbox and session view for composing and managing radio email. Select hardware packet or internet Telnet transport; account and RMS settings are kept on their own settings page.
Packet receive timing and end-to-end RF exchange remain an area of ongoing testing.
SSTV
Robot36 slow-scan television with automatic image reception, saving received pictures, and selecting an image for transmission. The page shows the frequency in use.
OVER-THE-AIR TEST PENDINGMDC1200
Independent receive and transmit options, a four-digit hexadecimal unit ID, and PTT IDs at the beginning, end, or both ends of a transmission. Decoded IDs and opcode details appear in analog Last Heard.
LOCAL CHECKS PASSED / RF TEST PENDINGDIGITAL, WITHOUT THE SMALL TALK
DMR SMS + CALL ALERT
Send private DMR texts and receive replies. Motorola-format messaging was verified with an AnyTone 878. Send a Call Alert or receive an on-screen notification with an audible alert.
OPERATOR-TESTED04 / INSIDE THE COMMAND CENTER
No mockups.
This is the app.
Actual screenshots captured from the connected CJ1. Select a category, then tap a screen to enlarge it.
ANALOG FM
Frequency, signal, squelch, scanning, and Last Heard.
DMR
Talkgroup, color code, time slot, and monitor control.
BRANDMEISTER
Talkgroups and private calls through your internet link.
PACKET RADIO
A terminal for connected BBS and node sessions.
SSTV
Receive, save, and select pictures for the air.
MEMORIES
Organize zones and import or export your codeplug.
DIAGNOSTICS
See what the radio and handset are actually doing.
MEASURE TWICE. CUT ONCE.
ANTENNA CALCULATOR
Enter a frequency for wavelength, half-wave dipole length, individual leg length, and quarter-wave vertical dimensions in meters and feet. Starting dimensions stay right in your field kit.
READ THE CONDITIONS.
PROPAGATION
Solar indices, HF day/night band guidance, VHF conditions, NOAA D-region absorption maps, and GPS-based local weather. Updates while the page is open and labels cached information with timestamps.
05 / THE DETAILS THAT MAKE IT YOURS
Designed around
the way you operate.
A codeplug that travels
Import and export Field Radio JSON memories. Organize up to 512 zones with 32 channels per zone. A companion single-page JSON editor supports sorting zones alphabetically and talkgroups by ID.
Useful Last Heard
Scrolling call history, timestamps, contact names, and callsigns make it easier to follow a busy channel. DMR and supported internet modes can show cached RadioID details, location, and country flags.
Field-friendly controls
Direct number menus for volume and squelch. Knob channel selection on hardware RF, knob master volume on RoIP, an optional keep-screen-on setting, and 75% foreground brightness.
Know the station
Diagnostics expose radio model, Android version and build, available RAM and storage, firmware, signal, audio activity, and the last delivered button event. Receive and transmit status change the top bar’s color.
06 / BEFORE YOU KEY UP
The operator’s
field guide.
Clear expectations for a project that keeps growing.
What hardware is this built for?+
CJ1 Radio Command is developed around the CJ1 / CJ_1UV Android radio and its onboard RF module. Hardware FM and DMR depend on that integration; this build is not a universal RF-radio app for an ordinary Android phone.
What works without internet?+
Hardware FM and DMR, local memories, and software audio modes such as analog APRS, packet, SSTV, and MDC1200 use the local radio path. GPS needs a fix for position reports. Internet voice networks, Telnet Winlink, and fresh online contact lookups require connectivity; cached contact information is retained.
Can the radio keep working in the background?+
The app uses a foreground service and a five-second connection watchdog. Background physical PTT has been operator-tested with the screen off. Android battery restrictions still matter, so the app includes a shortcut to its background battery settings.
Does APRS Smart Beaconing interrupt voice?+
It shares the same RF hardware rather than providing a second independent receiver. The app waits for an idle opportunity, switches to the configured APRS frequency, sends the beacon, and returns to voice. Active transmission or other busy conditions defer the beacon.
Which features still need live testing?+
M17 live voice confirmation is pending. EchoLink awaits account validation and live login/voice testing. SSTV and MDC1200 have local software checks but still need over-the-air validation. Packet and Winlink RF receive/exchange behavior remain in development. A link or local test is not treated as proof of end-to-end RF operation.
What does P25 or D-STAR support mean here?+
These are internet reflector voice clients under the globe menu. The CJ1 hardware RF modes remain analog FM and DMR. P25 trunking, P25 Phase 2, encrypted voice, and hardware D-STAR are not part of this feature set.
Is this a finished commercial product?+
This is an actively developed amateur-radio project by Michael D. Hopwood Jr, KE5EUA. The available APK is a development build, not a Play Store release. Features and test status reflect version 1.23.1, documented on October 21, 2026.
BUILT BY A HAM. BUILT TO KEEP EXPLORING.
Take command
of your CJ1.
One place for the everyday contact—and the next experiment. Follow the signal, try a new mode, and make the station your own.
DOWNLOAD ANDROID APK ↗v1.23.1 · Development build · CJ1 hardware required for RF
Package: com.ke5eua.cj1radioham