Single Sideband (SSB): How does it do that? (036)

Video Description

Single Sideband (SSB) is the standard mode of voice communication for HF operation in Amateur Radio across the globe. It was used for Intercontinental Telephone communication long before it found its way into Amateur Radio (1923). In this video I will help you understand the How and Why of Single Sideband communication both on the Transmit side and the Receive side. I start with its foundation in the world of Amplitude Modulated Phone and how it evolved into modern Single Sideband. When you look at the spectral content of the AM and the DSB Suppressed Carrier signals, you will notice that there are multiple sideband pips at 1xModulating Frequency, Fm, 2xFm, 3xFm, etc. away from the carrier. It turns out that the pips at 2xFm and above are due to distortion of the audio, not the "ideal" signal. I discovered this through the mathematical investigation into the "ideal" AM signal which only contains the carrier, Fc, and one sideband pip at Fm away from the carrier on either side of the Fc, carrier. Furthermore, the real world mixer is not necessarily linear. This fact also adds to the additional sideband pips (and the F1 +/- (F2*n) reality). If you are interested in playing with this, I've provided the link to my GNU Octave file, below. I have provided a link to a very interesting video on the history of Single Sideband in the promised links, below. It is 47 minutes long, but contains a lot of cool information. The presenter is Ed Gable (no relation of mine). Promised Links: AM, LSB and USB Spectral Content Compared (IC-7610 experiment) Spreadsheet https://drive.google.com/file/d/1eNx9kYhcokmrtD3wYco1Z4nT0EYcaZDr/view?usp=sharing GNU Octave Simulation & Frequency Content of an Ideal AM Signal https://drive.google.com/file/d/1gKzNpNxZHEbXFszUnJihXwgevb5M-Aul/view?usp=sharing The History of Single Sideband (Antique Wireless Museum) https://www.youtube.com/watch?v=BBRntPJTr5Y Time Markers for Your Convenience ---------------------------- 00:05 Introductory Comments 01:10 Amplitude Modulation, S.S.B.'s foundation 01:29 Definition of Terms 01:38 Modulation 02:03 Carrier 02:49 What is Amplitude Modulation? 02:57 Amplitude 03:25 A.M. Demo-Introduction 03:59 Time Domain 04:37 Frequency Domain 05:48 Double Sideband, Suppressed Carrier: Introduction 06:56 Generating the Signal 09:27 DEMO: The Tour of the Hardware 10:14 Time Domain 10:50 Frequency Domain 11:44 Single Sideband: Introduction 12:19 A Little Amazing History 13:07 How do we generate the signal? 14:28 Receiving SSB: Introduction 15:07 How do we do that? 15:10 Carrier Injection 15:58 The Product Detector 17:07 Final Comments and Toodle-Oots -----------------------------