HF Digital Modes
•Download as PPTX, PDF•
0 likes•286 views
A light introduction to HF digital communication modes used in amateur radio. Presented to the HacDC amateur radio club.
Recommended
More Related Content
Similar to HF Digital Modes
Similar to HF Digital Modes (20)
Recently uploaded
Recently uploaded (20)
HF Digital Modes
- 1. HF Digital Modes Andrew Beard AB3U
- 4. Radio • Must be able to do Upper Sideband (USB) • The less signal processing, the better • Just because we’re doing digital doesn’t mean it has to be new
- 7. Keying PTT
- 9. WSPR • One-way position beacon • Spotters report received beacons via the Internet • 6 Hz of bandwidth! • 111 seconds to transmit, 9 seconds off • Callsign, TX power, grid square. That’s it
- 10. JT-65 • Very structured two-way mode • 48 seconds of transmit, 12 seconds of idle • Max of 13 freeform characters per message • Very good error correction; it’s right or you don’t get it
- 12. PSK31 • “Keyboard” digital mode • Common for contesting, ragchewing, or anything in between • Very little error correction • A lot of CW shorthand
- 14. Things to consider • ALC is not your friend (in most cases) • Turn off audio equalization • Cut max TX power in half of rated max for phone • Shielded cables (especially if TX gets stuck) • Don’t use more power than what you need
- 15. Who is drifting? You Them
Editor's Notes
- Ham shack, front door, most of living room Tiny Bedroom
- For SDRs, Virtual Audio Cable For tablets and phones can use a TRRS splitter and use built in audio Same is true for PCs, but keep audio quality in mind. Not all created equal.
- Usually software, but not always True modem, modulate and demodulate
- VOX, especially if built into the radio. External (like signalink) available Simple, serial as GPIO Newer radios, serial commands (possibly USB)
- No text. No replies
- Great low-stress beginner mode Time sync is critical! Use NTP, etc
- Lack of error correction – reading drunk texts CW shorthand (end in k, kn, sk) WA0IDK de AB3U
- You: Everybody shifts. Them, take a look at the guy at 1700 or so. Everyone else is straight