On The Art of NDB DXing


From early 1987 to the summer of 1989, a now-legendary series of twelve articles by Sheldon Remington (KH6SR) appeared in The LOWDOWN. Conceived as part of a larger work, "On The Art of NDB DXing" educated a generation of DXers in the finer points of longwave monitoring--techniques applicable not only to the search for nondirectional aero and marine navigation beacons, but also LowFERs and other hard-to-hear LF signals.

Now, "On The Art of NDB DXing" returns home, in a manner of speaking... with this, the first authorized Web version. Through the kind cooperation of the author, this series is now available to you with most of its original content intact.

Please note that this is still a work in progress. The entire series could be revived at some point if there is enough interest. Also please note that some additional Terms of Use apply to these documents, beyond those in effect for most of the LWCA site.

1 Introduction
What NDBs are, and where they are used.
2 The Spurious Response Problem
Receiver problems, overload cures, commercial filters, homebrew filters, external rectification, miscellaneous external causes.
3 Man-Made Noise (Part 1)
Offensive Strategy -- TV oscillator interference; broadband power line noise; the politics of RF pollution.
4 Man-Made Noise (Part 2)
Mechanically Steered Nulling -- The directionality of power line noise; tuned loops; untuned loops; other movable antennas.
5 Man-Made Noise (Part 3)
Electrically Steered Nulling -- Phasing by reactance; phasing by rotating coils; nulling procedure; noise bridges.
6 Man-Made Noise (Part 4)
Blankers and RF Wrapup -- Synchronous blankers; natural noise; limiters; further antenna considerations; receiver noise, gain, and preamps.
7 The Frequency Domain (Part 1)
Modulation and Pitch -- Frequency assignments; modulation; pitch.
8 The Frequency Domain (Part 2)
QRM, Frequency Clusters and Selectivity -- Sidebands; cluster spread; IF selectivity; AGC and BFO requirements; bandpass audio filtering; notch filtering.
9 The Frequency Domain (Part 3)
Frequency Measurement and Defects -- Coarsely calibrated receivers; closely calibrated receivers; external frequency-measurement apparatus; beacon defects in the frequency domain, including negative keying.
10 Beacons On The Road
Portable receivers; mobile and temporary receiving antennas; loops and direction finding.
11 Visiting Beacon Sites
How to find them; beacon antenna configurations.
12 The Time Domain (Part 1)
Idents and Formats -- the Morse code; NDB identifiers; ident problems; formats in different countries.

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