DTMF & CW Commands

DD – DTMF Duration

Sets the duration of DTMF tones.

Syntax

DDnnnn
DD?

Parameters

Parameter	Range	Description
nnnn	0050–2000	Duration in milliseconds

Default

0500 (500 ms)

Examples

DD0500          # 500 ms (default)
DD0100          # 100 ms (fast)
DD1000          # 1 second
DD?             # Query current setting

Notes

• All 4 digits required
• Includes both tone and inter-digit pause
• Longer durations improve decode reliability
• Shorter durations allow faster dialing

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DR – DTMF Detector

Enables or disables the DTMF tone detector.

Syntax

DRn
DR?

Parameters

Value	Description
0	DTMF detection OFF
1	DTMF detection ON

Default

0 (OFF)

Examples

DR1             # Enable DTMF detection
DR0             # Disable DTMF detection
DR?             # Query current state

Output

When enabled and a DTMF tone is detected, the hex value is sent via serial:

• Tones 0–9 → 30–39 (ASCII ‘0’–‘9’)
• Tone A → 41
• Tone B → 42
• Tone C → 43
• Tone D → 44
• Tone * → 2A
• Tone # → 23

Notes

• DTMF detection works best with VU around 10–15
• Used for remote control applications
• Can trigger Arduino DOUT pin (see AO2)

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DS – Send DTMF

Sends a string of DTMF tones.

Syntax

DS<string>

Parameters

Character	Description
0–9	Numeric tones
A–D	Letter tones
*	Star
#	Pound
other	Pause (inter-digit gap)

Examples

DS123           # Send "1", "2", "3"
DS*123#         # Send "*123#"
DSA1B2C3D4      # Send "A1B2C3D4"
DS1 2 3         # Send "1", pause, "2", pause, "3"

Notes

• Maximum 28 characters
• Automatically keys TX if not already transmitting
• Duration per tone set by DD command
• Non-DTMF characters create pauses

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CT – Send MCW

Sends text as modulated CW (FM audio tones).

Syntax

CT<text>

Examples

CTCQ CQ CQ      # Send "CQ CQ CQ" as audio CW
CTWA2EUJ        # Send callsign
CT73 DE WA2EUJ  # Send message

Notes

• MCW = Morse code as audio tones on FM carrier
• Can be received with any FM receiver
• Speed set by CS command
• Tone frequency set by CF command
• Maximum 28 characters
• Automatically keys TX

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CW – Send CW

Sends text as true CW (on-off keyed carrier).

Syntax

CW<text>

Examples

CWCQ CQ CQ      # Send "CQ CQ CQ" as true CW
CWWA2EUJ        # Send callsign

Notes

• True CW = carrier keyed on/off
• Requires CW/SSB receiver to decode
• Can use CW portions of bands
• Speed set by CS command
• Maximum 28 characters
• Automatically keys TX

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CF – CW Frequency

Sets the audio tone frequency for MCW and sidetone.

Syntax

CFnnnn
CF?

Parameters

Parameter	Range	Description
nnnn	0400–1300	Frequency in Hz

Default

0650 (650 Hz)

Examples

CF0650          # 650 Hz (default)
CF0800          # 800 Hz
CF1000          # 1000 Hz
CF?             # Query current frequency

Notes

• All 4 digits required
• Affects MCW transmission and sidetone
• True CW (CW command) uses carrier, not this tone
• Choose frequency that’s comfortable to listen to

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CS – CW Speed

Sets the Morse code sending speed.

Syntax

CSnn
CS?

Parameters

Parameter	Range	Description
nn	05–25	Speed in words per minute

Default

22 WPM

Examples

CS15            # 15 WPM
CS22            # 22 WPM (default)
CS12            # 12 WPM (slow)
CS?             # Query current speed

Notes

• Both digits required (CS15 not CS1)
• Affects CT, CW, ID, and beacon messages
• Standard word is “PARIS” (50 elements)

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CL – Callsign

Sets the callsign for CW identification.

Syntax

CL<text>
CL?

Parameters

Parameter	Description
<text>	Callsign, up to 15 characters

Default

‘RS-UV3’

Examples

CLWA2EUJ        # Set callsign
CLWA2EUJ/R      # Callsign with suffix
CL?             # Query current callsign

Notes

• Used by ID command and IT timer
• Maximum 15 characters
• Typically your amateur radio callsign

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ID – Send ID

Sends the stored callsign as CW.

Syntax

ID

Examples

ID              # Send callsign in MCW

Notes

• Sends callsign set by CL command
• Automatically keys TX
• Uses speed and frequency from CS/CF
• No parameters required

Related Commands

• CL — Set callsign
• IT — Automatic ID timer

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SD – Sidetone

Enables or disables CW/DTMF sidetone through the speaker.

Syntax

SDn
SD?

Parameters

Value	Description
0	Sidetone OFF
1	Sidetone ON

Default

0 (OFF)

Examples

SD1             # Enable sidetone
SD0             # Disable sidetone
SD?             # Query current state

Notes

• Allows monitoring CW and DTMF transmissions
• Sidetone level controlled by GT command
• Frequency controlled by CF command (for CW)