SSTV: Difference between revisions
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Slow scan television! | Slow scan television! | ||
Software | SSTV is a method for transmitting images that was pioneered by ham radio operators. It transmits images using a very narrow bandwidth, approximately the same as a single sideband (SSB) voice signal - 3 kHz. It is essentially a translation of image data into audio tones that can be transmitted over the radio, and then back into images. | ||
Why is this a big deal? First, because normal, moving television images require signals with a bandwidth 2,000 times larger (6 MHz). This saves a huge amount of spectrum space, making this mode usable on lower frequencies (HF/VHF) and not just restricted to higher frequencies. SSTV is also cheaper - you aren't operating microwave transmitters and drawing thousands of watts to transmit your signal. You can use existing equipment and radio transceivers designed for SSB voice signals at a bandwidth of 3 kHz. This makes it easy to receive an SSTV signal with a VHF radio and pipe it over to a sound card for slow scan TV software to take over. | |||
The technology dates back to 1968, when amateurs were first granted spectrum space to do slow scan TV. Slow scan TV was also utilized during the Apollo lunar missions. | |||
You can find a sample of what slow scan TV signals sound like here: [[File:JupiterSSTV.wav]] | |||
==Software== | |||
[[Qsstv]] | |||
Revision as of 20:39, 11 August 2016
Slow scan television!
SSTV is a method for transmitting images that was pioneered by ham radio operators. It transmits images using a very narrow bandwidth, approximately the same as a single sideband (SSB) voice signal - 3 kHz. It is essentially a translation of image data into audio tones that can be transmitted over the radio, and then back into images.
Why is this a big deal? First, because normal, moving television images require signals with a bandwidth 2,000 times larger (6 MHz). This saves a huge amount of spectrum space, making this mode usable on lower frequencies (HF/VHF) and not just restricted to higher frequencies. SSTV is also cheaper - you aren't operating microwave transmitters and drawing thousands of watts to transmit your signal. You can use existing equipment and radio transceivers designed for SSB voice signals at a bandwidth of 3 kHz. This makes it easy to receive an SSTV signal with a VHF radio and pipe it over to a sound card for slow scan TV software to take over.
The technology dates back to 1968, when amateurs were first granted spectrum space to do slow scan TV. Slow scan TV was also utilized during the Apollo lunar missions.
You can find a sample of what slow scan TV signals sound like here: File:JupiterSSTV.wav
Software
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SSTV (slow scan television) a method for sending television and static images using 1,000 times less bandwidth than a television signal.
Slow scan television: SSTV
Category:Radio · Category:SSTV · Category:Ham Radio Flags · Template:SSTVFlag · e |
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radio all things radio.
Ham Radio: Notes on General class license: General · Mnemonics/General Class License Digital modes: Radio/Digital Modes
Ham Radio Hardware (Radios): Kenwood TS 440S: Radio/Kenwood/TS440S Kenwood TS 570S: Radio/Kenwood/TS570S Yaesu VX-6: Radio/Yaesu/VX-6 Digital Modes on Raspberry Pi: RaspberryPi/Digital Modes Digital Modes on Arduino: Arduino/Digital Modes DVB-T USB SDR Dongle: DVB-T USB SDR
Ham Radio Software: Software defined radio: SDR Comprehensive list of ham software: Andys Ham Radio Linux Direwolf (soundcard TNC/APRS modem): Direwolf Echolink (internet repeater system): Echolink Qsstv (Slow scan television): Qsstv Fldigi (fast light digital modes): Fldigi Xastir (APRS/AX25/TNC): Xastir RadioHead (packet library for microcontrollers): RadioHead
Category:Radio · Category:Kenwood · Category:Yaesu Flags · Template:RadioFlag · e |