SSB plus Video Rick Peterson, WA6NUT

Introduction "SSB plus Video is a sound card-based mode enabling simultaneous audio and video using HF transceivers. "SSB plus Video uses software by Con Wassilieff, ZL2AFP, modified to allow 990 Hz bandwidth for the voice signal. "Live (webcam) video or AVI video clips can be sent at a frame rate of 1 FPS with 36 line resolution. The video clips can be played back at frame rates up to 10 FPS.

The SSB plus Video Signal " SSB plus Video uses an analog frequency division multiplexed (FDM) signal with 49 FM'ed subcarriers, with Hz spacing between the subcarriers. 36 subcarriers are used for luminance information, 13 sub- carriers are used for chroma. The first subcarrier is at 1292 Hz baseband. " The audio is analog, lowpass filtered with a - 3 dB rolloff at 990 Hz baseband.

Software "Two versions of the SSB plus Video software are available, the AFC version (for tracking frequency drift in the transceivers), and the non-AFC version. "Each version includes a TX application (for transmitting "live" video or video clips), an RX Display/Record application, a PTT application, and an RX Playback application (this application is used to play back and display received AVI clips at up to 10 FPS). An.ini file is also included to allow a user-defined text "crawl" at the bottom of the transmitted video.

Hardware "The SSB plus Video signal requires a TX and RX bandwidth of 3.5 kHz for the HF transceiver. A list of suitable HF SSB transceivers is found on NU9N's website. "The received SSB plus Video signal is tuned with a "waterfall" display found in most PSK31 software. A USB sound adapter is used in addition to the PC's sound card. "A sound card interface, used with all sound card modes, is required (with serial port)

Hardware (cont.) "If your PC doesn't have a serial port, you'll need a USB-to-Serial cable for PTT control of your transceiver from the PC's mouse. "A USB webcam (not required for SSTV, or if you'll only send video clips). "The SSB Audio/Video Processor: This is a project you can build. The Processor has lowpass and highpass filters used for the audio and video signal, respectively, plus TX/RX switching circuits.

Building the Processor " The Processor requires the assembly of 4 printed circuit boards (PCB's). Two of the boards use custom PCB's (available online from BatchPCB) and the other 2 boards are simple kits from Velleman. Parts for the 2 custom PCB's are available online as parts kits from Mouser or Digi-Key. The remaining parts are available online from Radio Shack, Jameco and others. The Processor is an advanced project (not for beginners).

Building the Processor (cont.) "The Processor is built in a Radio Shack aluminum project box (some drilling required). "No calibration is required – the only adjustments are setting the gain of the Velleman preamps and setting the Audio/Video mixer control. "A post-build test procedure is available. "A Yahoo! Group has been set up for builders and users of the Processor.

Operating with SSB plus Video " SSB plus Video can be considered "face-to- face" HF amateur radio, with on-air "eyeball QSO's". " Operation is currently on kHz, a frequency shared with digital voice (with digital voice the primary user and SSB plus Video a secondary user, per the bandplans). " You're invited to join us!

How's DX? "ZL2AFP has developed several types of narrow band TV. SSB plus Video uses his "FFT-TV" mode (also known as analog OFDM). FFT-TV provides the fastest frame rate at 1 FPS. ZL2AFP and Murray Greenman, ZL1BPU, have regular skeds on 80M between Wellington and Auckland, NZ, a distance of several hundred kM. "FFT-TV has been used on 20M over the 800 mile path between St. Paul, MN and Buena Vista, CO (ACØX and WA6NUT).

References " Adonis Electronics has marketed a processor similar to the SSB Audio/Video Processor: " A complete information package (a 5.5 MB zip file) can be downloaded from: Read the "SSB plus Video Info" file first. " The most current information is on the Yahoo! Group page at:

References (cont.) " ZL1BPU maintains a website devoted to the various versions of Narrow Band TV (NBTV) developed by Con Wassilieff, ZL2AFP: " NU9N maintains a list of "eSSB-ready" HF transceivers, most of which are suitable for SSB plus Video (3.5 kHz bandwidth), at:

For more information... " Download the "CO49-Voice" zip file from the URL provided. " Contact Rick Peterson, WA6NUT at: arrl.net " Any questions?