Amateur Radio Club of the National Electronics Museum | K3NEM

Rol Anders', K3RA, weekly Amateur Radio Operating Course held at the NEM. This week's lesson is on Digital Communication modes.

Preparation for the next class:

Please read the chapter on digital communications this week, and bring in any questions you may have.
An interesting website to go to is http://www.astrosurf.com/luxorion/qsl-audiofiles.htm This has audio recordings of many different ham radio modes and activities.

Besides the information provided in the book, I'll cover the following:

Bit of philosophy and technology behind PSK31--how it works and why it is so popular.

Comparisons of error rate vs. signal to noise ratio for various digital modes. Info based on a QEX article reporting lab simulations of real propagation flutter, Doppler, multipath, and Gaussian white noise.

Some info on:
Olivia

MT63

WSJT

* FSK441, designed for high speed meteor scatter
* JT6M, optimized for meteor and ionospheric scatter on 6 meters
* JT65 for Earth-Moon-Earth (EME) and weak troposcatter
* CW for EME using timed, computer-generated transmissions.
* Experimental JT-2 and JT-4

Pactor - a bit more info the various Pactor I, II, and III

A little more on digital voice, including FDMDV mode.

A little more on MFSK theory than the book provides.

I'll discuss very briefly some of the less common modes like Clover, Contestia and DominoEX

I hope to demo PSK31, and other modes I can find in the evening on 40 and 80. We have a good chance at finding RTTY, and with luck some of the less common modes like Olivia and FeldHell. I hear very little Pactor or Packet anymore on HF. There never was much ASCII mode, and AMTOR is long gone. I don't think Clover and its deriviatives were ever very big.