Look at the entries here — Page 393, Lesson 407

This is the index of the book — the alphabetical listing of every topic and where to find it. I want to walk you through how to read this, because it's a map of the entire syllabus, and it tells you exactly what you'll be tested on. Look at the entries here. You've got TO/FROM at pages 118 and 121 — that's the VOR indicator showing whether you're flying toward or away from a beacon. TONE at page 89, and TONE/VOICE at page 89 — that's the ADF receiver's audio selection, choosing between the Morse identifier tone and the voice broadcast. Tracking Inbound at page 92, and Track Maintenance at page 91 — those are the two core skills of flying a bearing to or from a station. Transmission Power at page 189 — that's about radar or DME output. Transponder at 183, 227, and 247 — the secondary surveillance radar transponder appears in three different contexts. Triple IRS at page 278 — that's three Inertial Reference Systems working together. Tropospheric Propagation Error at page 317 — that's the GNSS error caused by the lower atmosphere bending the signal. TRSB at page 174 — that's Time Reference Scanning Beam, the MLS landing system. Turbulence at 213, TVOR at 116 — that's a Terminal VOR, a low-power VOR for approach use. Twin FMC at 277, Twin IRS at 277 — dual Flight Management Computers and dual Inertial Reference Systems. Twin Pulses at 249 — that's the DME pulse pair. Twin Wire Feeder at 56 — that's the antenna transmission line. Then under U: Ultra High Frequency (UHF) at page 8 — that's the 300 MHz to 3 GHz band. Unique Address at 235 — that's the 24-bit aircraft address for Mode S. Upper Sideband (USB) at 44 — that's the HF voice mode. US DOD at 318 — the US Department of Defense, who run GPS. User Segment at 307 and 311 — that's the receiver part of GNSS. UTC at 307 — Coordinated Universal Time, the time reference for GPS. Under V: Variable Phase at 112 — that's the VOR signal component that rotates. VDF at 75, and VDF Summary at 79 — VHF Direction Finding, the ground station that gives you a bearing. VDOP at 318, and Vertical Dilution of Precision at 318 — that's the satellite geometry factor affecting vertical accuracy. Very High Frequency (VHF) at page 8 — the 30 to 300 MHz band. And VHF Direction Finder — that's the start of the VDF entry, which continues on the next page. Now, here's the key point about this index: it's not just a list. It's your revision checklist. Every one of these terms — TO/FROM, TRSB, VDOP, Twin Pulses — is a topic you must be able to define, explain, and apply. When you see a page number repeated, like Transponder at three pages, that tells you the topic appears in multiple contexts — radar, DME, and GNSS — and you need to understand it in each one. The page numbers also tell you the structure of the book. Radio navigation fundamentals are early — pages 8, 44, 56. VOR and ADF are in the 80s to 120s. Radar and transponder are in the 180s to 250s. And GNSS is at the end, pages 307 to 318. So as you work through the chapters, you can tick these off. That's the index. It's your map. Now, when you're ready, we move into the actual content — the first topic in the book is the radio frequency spectrum, starting with VHF and UHF at page 8.