Just in case you missed the EME and EMW sound FX on the info page I've put them on here for you to "point 'n' click" at. I also hope to include some other NDB's from around my local area...
The beacons were recorded at various "quiet" locations using my Sony ICF2001D receiver and an old ITT "Studio 66" 1970's vintage cassette recorder.
Back at base the cassette recordings were transferred onto the PC via the sound card, 11Khz mono sampling rate, then cleaned up and edited with Win98's sound recorder.
I found this excellent FFT program Written by RS Horne, which can be found at http://www.monumental.com/rshorne/gram.html. It can be used to examine recordings of NDB's or other weak signals over a period of time. Here is an example of the EMW sample file being analysed in Spectrogram:
Last Updated 13 September 1999 21:11