That’s a PFC, or “prepared form card,” which I used when I was DXing LW aerobeacons. I’d send that with a SASE as a QSL when verifying beacons. A directory of LW beacon verification addresses – mostly in the SE USA – is also on this site; check the menu on the right.

Aviation Resources

Codes Worldwide airport codes.
FSDO Flight Standards District Office Locator Home Page

Canadian Resources

Canadian NDB List by Pierre Thomson.
List of Lights, Buoys, and Fog Signals. Newfoundland, Atlantic Coast, Inland Waters and Pacific Coast.
Transport Canada Homepage in English and French.

Clubs and Discussion Groups

LWCA. The Longwave Club of America. They publish a monthly journal relating to the longwave radio hobby.

Other Hobbyist’s Pages

Signals Received in North America. Online database.
The VE7SL Radio Notebook. Photos of NDB’s, loop antenna plans, and more.
Alex Wiecek’s LW Page. Beacon loggings and images.
Beacon’s A Bunch AC6V’s LW links.
DXing.com. DXing.com’s longwave DXing page–includes info on Ken Stryker’s beacon guide.
NDB Beacon Logger. Real-time reports.
Rock’s Ray Rocker’s Beacon Log (hey, is that his real name?)
Tim Noonan Radio/DX Information from Wisconsin–inlcluding NDB info.
Beacon World Alan Gale’s site in the UK (with list of UK NDBs).
World Below 535 kHz. Links and photos from SV1XV.
The Lord Howe Island NDB lots of pictures by William Tidmarsh. [web archive at archive.org]
Long Wave Beacons in Wisconsin With freq and other helpful information.
Using your computer to ambush unsuspecting NDBs… using Spectran.

Software

Bearing1.zip Bearing/distance calculator.

Some Great WWW Resources

AirNav. Search for A Longwave Beacon.
ANARC Glossary. Glossary of radio terms from “All Wave” to “Util.”
Altair’s Lowfer Page – Station YWK. 184.320 kHz.
Definition of a radiobeacon.
Frequencies. Worldwide frequency allocation table.
How Low Can You Go? An introduction to longwave DX from the New Zealand Radio DX League.
Lighthouse Getaway. Detailed info and photos of lighthouses in the USA & Ireland.
Lost at Sea: The Search for Longitude From NOVA Online.
Longwave Home Page. A ton of info, files, an interactive message board, etc. relating to the LW radio hobby.
Navaid History. National Park Service page about historical maritime navigational sites–like lighthouses.
SA. Southern Avionics’ page about navaids (they make NDBs).
Low/Medium Freq Aero Beacon System Of The U.S. Cool page by Kriss Larson w/maps. [archived at archive.org]
1996 Federal Radionavigation Plan PDF file explaining govt’s plan to phase out NDBs.
1999 Federal Radionavigation Plan PDF file (The govt’s “navaid master plan”–produced every 2 years.)
2001 Federal Radionavigation Plan links to PDF.
2005 Federal Radionavigation Plan PDF file.
2008 Federal Radionavigation Plan PDF file.
Lighthouses, Lightships, Tenders & Other Aids to Navigation Subjects USCG.
RN Radio Netherland’s longwave radio links page.
USCG Navigation Center Searchable.
NATON National Aids To Navigation School.
A history of buoys and tenders by Amy K. Marshall.
NASA online VLF receiver Listen on the web to the INSPIRE VLF radio receiver at NASA’s Marshall Space Flight Center in Huntsville, AL.
AMRAD Low Frequency Web Page from the Amateur Radio Research and Development Corporation.
Northern Star Longwave Radio Beacons pictures.