The 20m Problem - The Truth - Long Haul DX and Take-Off Angles скачать в хорошем качестве

The 20m Problem - The Truth - Long Haul DX and Take-Off Angles

In this video I dive into 20-metre band (and above) and why it behaves so differently to 40m. We recap the D-layer “sponge,” explore how the F-layer splits into F1 and F2 under sunlight, and talk about take-off angles, hop lengths and long-haul DX. With graphs, a few invented words like “jigglification,” and plenty of plain English, this is a look into how 20 m propagation really works — and why it can be both magical and maddening at the same time! (Warning: contains maths, PDFs, and raw data files. Proceed only if heavily caffeinated.) 📚 ARRL Antenna Book – Supplemental Files (23rd Edition) https://www.arrl.org/files/file/Anten... 📄 Installation Summary (PDF) – explains where the HFTA statistical elevation-angle files live https://www.arrl.org/files/file/Anten... 📊 HFTA Documentation (PDF) – dense but explains how to interpret the elevation-angle distributions https://www.arrl.org/files/file/Anten... 🌐 VOACAP Online (Point-to-Point Propagation) – generate your own AoA tables and predictions http://www.voacap.com/p2p/ 📚 VOACAP Technical Docs – everything you never wanted to know http://www.voacap.com/documents.html 📰 QEX (Siwiak, May–Jun 2011) – statistical elevation angles across HF; 50% below 6°, 90% below 16° https://www.arrl.org/files/file/QEX_N... 00:00 Intro 00:20 Recap on D Layer 00:40 The F Layer 02:06 Take-Off Angles 03:07 Long Haul DX 06:39 Take-Off Angle Chart 09:03 What happens at night? 10:26 WSPR 11:49 Why Oceans Assist 12:19 Long Path to VK / ZL 13:31 When F1 and F2 Combine 15:23 Wrap-Up Conclusion