Beacon Operation

The RS-UV3A has built-in beacon functionality for transmitting periodic CW identification or messages. This is useful for propagation studies, fox hunting, and repeater ID.

Beacon Types

The RS-UV3A supports two beacon modes:

Type	Command	Description
MCW (Audio CW)	BT	FM carrier with CW-modulated audio tone
True CW	BC	On-off keyed carrier (OOK)

MCW vs True CW

MCW (Modulated CW):

• Transmits on FM frequencies
• Can be received with any FM receiver (HT, mobile radio)
• Must be used in voice portions of the band

True CW:

• Traditional on-off keying
• Requires a CW receiver (SSB/CW mode)
• Can be used in CW/data portions of bands
• Better range due to narrower bandwidth

Setting Up a Beacon

Step 1: Set the Beacon Message

BMWA2EUJ        # Simple callsign
BMWA2EUJ BEACON # Callsign with text
BM?             # Query current message

Maximum message length is 32 characters. Valid characters:

• Letters A–Z
• Numbers 0–9
• Punctuation: period, comma, question mark, slash
• Space

Step 2: Set CW Parameters

CS15            # 15 WPM (words per minute)
CF0800          # 800 Hz tone frequency
CS?             # Query speed
CF?             # Query frequency

Speed range: 5–25 WPM Tone range: 400–1300 Hz

Step 3: Set the Beacon Timer

For MCW beacon:

BT120           # Send beacon every 120 seconds (2 minutes)
BT600           # Every 10 minutes (maximum)
BT060           # Every 60 seconds (minimum)
BT000           # Disable beacon

For true CW beacon:

BC120           # Send CW beacon every 120 seconds
BC000           # Disable beacon

Note

Setting BT automatically disables BC, and vice versa. Only one beacon type can be active.

Advanced Beacon Features

Carrier Insertion (True CW Only)

In true CW mode, you can insert unmodulated carrier segments for DF (direction finding):

BM#10WA2EUJ     # 10 seconds of carrier, then callsign
BMWA2EUJ#05     # Callsign, then 5 seconds carrier
BM#15WA2EUJ#10  # 15s carrier, call, 10s carrier

The #nn syntax inserts nn seconds of unmodulated carrier (1–30 seconds).

Message Repeat

Use & to repeat the message continuously during the beacon:

BMWA2EUJ &      # Repeats "WA2EUJ" until timer expires

Everything after & is sent once at the end.

Multi-Channel Beacons

Send beacons on multiple frequencies by storing different frequencies in memory channels:

# Setup channel 1
FS144275        # 2m frequency
PW1             # High power
ST1             # Save to channel 1

# Setup channel 2
FS222100        # 1.25m frequency
PW1             # High power
ST2             # Save to channel 2

# Setup channel 3
FS432100        # 70cm frequency
PW0             # Low power (different power level example)
ST3             # Save to channel 3

# Enable multi-channel beacon
MC3             # Cycle through channels 1-3
BT120           # Beacon every 2 minutes

The beacon will:

1. Recall channel 1, transmit beacon
2. Wait 2 minutes
3. Recall channel 2, transmit beacon
4. Wait 2 minutes
5. Recall channel 3, transmit beacon
6. Wait 2 minutes
7. Return to channel 1, repeat…

To disable multi-channel mode:

MC0             # Single channel beacon

CW Sidetone

Enable sidetone to hear the CW through the speaker:

SD1             # Sidetone on
SD0             # Sidetone off (default)

The sidetone level follows the DTMF/CW gain setting:

GT08            # Default tone gain
GT12            # Louder tones

Manual CW Transmission

Send CW messages on demand:

CTWA2EUJ        # Send "WA2EUJ" as MCW (audio)
CWWA2EUJ        # Send "WA2EUJ" as true CW

Maximum manual message length is 28 characters.

Fox Hunting Setup

For a hidden transmitter (fox hunt):

FS146565        # Out-of-the-way frequency
BMFOX           # Simple message
BC060           # Beacon every minute
PW0             # Low power for nearby hunting
ST0             # Save settings

For longer-range hunts, use true CW with carrier segments:

BM#30FOX        # 30 seconds carrier + "FOX"
BC120           # Every 2 minutes
PW1             # High power

Propagation Beacon

For propagation studies across multiple bands:

# Store frequencies for each band
FS144280
ST1

FS222100
ST2

FS432400
ST3

# Configure beacon
BMWA2EUJ/B QTH  # Beacon message with locator
CS12            # Slow speed for weak signal copy
MC3             # Three bands
BC300           # Every 5 minutes

Beacon with External Controller

For more sophisticated beacon applications (APRS beacons, GPS-based beacons), connect an Arduino or Raspberry Pi:

1. Connect MCU to JP1 (serial + control)
2. Use CT or CW commands to send messages
3. Use TX1/TX0 for transmitter control
4. MCU handles timing and message generation

This allows:

• GPS-derived position beacons
• Temperature/telemetry beacons
• Conditional beacons (only when conditions met)

Stopping a Beacon

BT000           # Disable MCW beacon
BC000           # Disable CW beacon

Or simply power cycle the RS-UV3A if beacon was not saved with ST0.

Complete Beacon Example

Setting up a 2m MCW beacon for a propagation test:

# Set frequency (beacon sub-band)
FS144280

# Configure CW
CS18            # 18 WPM
CF0750          # 750 Hz tone
SD1             # Enable sidetone to verify

# Set message
BMWA2EUJ/B FN20 # Call + grid square

# Set timing
BT180           # Every 3 minutes

# Set power
PW1             # High power

# Save to channel and as default
ST1             # Save to channel 1
ST0             # Save as power-on default

The RS-UV3A will now beacon every 3 minutes until power is removed or beacon is disabled.