FSQ

FSQ

Frequencies	3.58 MHz,7.104 MHz,10.149 MHz
Frequency Range	3.58 MHz - 10.149 MHz
Mode	USB
Modulation	IFK+
ACF	—
Emission Designator	—
Bandwidth	300 Hz
Location	Worldwide
Short Description	Fast Simple QSO (FSQ) is an amateur radio digital modulation mode developed by Con Wassilieff ZL2AFP with Murray Greenman ZL1BPU in 2015.
I/Q Raw Recording	—
Audio Sample

Fast Simple QSO (FSQ) is an amateur radio digital modulation mode developed by Con Wassilieff ZL2AFP with Murray Greenman ZL1BPU in 2015. FSQ is used on HFHigh Frequency (3-30 MHz) on fixed frequency channels. VHFVery High Frequency (30-300 MHz) adaptions of FSQ are also supported using VHFVery High Frequency (30-300 MHz) FMFrequency Modulation. FSQ uses IFK+Offset Incremental Frequency Keying and has efficient alphabet encoding as well as no need for syncing to receive. The FSQ modulation, coding and FSQCall protocol are publicly disclosed and described, and the software is open source.

FSQ is intended for fixed frequency (channelized) operation, with dedicated calling frequencies. It isn't intended as a 'tune around to see what you can find' mode!

Characteristics

FSQ is essentially a speeded-up version of the weak-signal mode WSQ2, introduced in 2013. It also uses 33 tones, in this case spaced 9Hz apart (actually 8.7890625 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., exactly 1.5 x the baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. rate at the highest speed), resulting in a signal bandwidth of 300Hz, including the keying sidebands. The ITU Emission Designator is 300HF1B. The modulation is constant amplitude, phase coherent MFSKMultiple Frequency Shift-Keying, using IFK+Offset Incremental Frequency Keying coding with 32 frequency differences, yielding 32 unique codes. This means that each symbol carries enough information for all lower case letters to be expressed in just one symbol, which greatly enhances the speed.

Some key features of FSQ:

• IFK+Offset Incremental Frequency Keying, providing drift-proof operation and good tolerance of multi-path interference.
• Efficient Alphabet, where most letters and punctuations can be sent in just 1 symbol.
• No synchronization required for decoding, allowing fast acquisition of signal
• Arbitrary transmission speed, allowing transmission and reception of baudrates at any rate between 2-6 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second., without requiring adjustment on the receiver's side.
• Chat operation, behaves like a messaging app.
• Supports selective calling functions,telemetry,image transfer, and file transfer functions.

Frequencies

Region 1

• 80m 3588 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (sunset to sunrise)
• 40m 7044 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (sunrise to sunset)
• 30m 10144 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (local day, DX night)

Region 2

• 80m 3594 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (sunset to sunrise)
• 40m 7104 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (sunrise to sunset)
• 30m 10144 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (local day, DX night)

Region 3

• 80m 3580 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (sunset to sunrise)
• 40m 7105 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (sunrise to sunset)
• 30m 10149 kHzKiloHertz (kHz) 10^3 Hz USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) (local day, DX night)

Decoding Software

Hobby Level Software

• FSQCall
• fldigi

Additional Links

• QSL FSQ Description
• AC4M Digital Modes: FSQ
• FSQ Powerpoint Presentation
• Ionospheric Performance of FSQ

Additional Images

FSQ using FSQCall reception and transmission