Editing Automatic direction finder (section)

==Typical service ranges of non-directional beacons (NDBs)==
Non-directional beacons in North America are classified by power output: "low" power rating is less than 50 watts; "medium" from 50 W to 2,000 W; and "high" at more than 2,000 W.<ref>{{cite web | title=ADF (Automatic Direction Finder) | url=http://www.allstar.fiu.edu/aero/ADF.htm | work=Navigation Systems – Level 3 | publisher=ALLSTAR Network | date=May 4, 2008 | access-date=17 October 2010 | archive-date=28 December 2010 | archive-url=https://web.archive.org/web/20101228212435/http://www.allstar.fiu.edu/aero/ADF.htm | url-status=dead }}</ref>

{| class="wikitable"
|-
! [[Non-directional beacon #Types of NDBs|Class]] of NDB, by&nbsp;power&nbsp;rating
! Transmission power output, [[watt]]s&nbsp;(W)
! Effective range, nautical&nbsp;miles&nbsp;([[nautical mile|nmi]])
|-
| Locator beacon
| 0–25
| 15
|-
| Low
| 0–50
| 25
|-
| Medium
| 50–2,000
| 50
|-
| High
| 2,000+
| 75
|}