How wide is an NDB approach course?

Andrey Serbinenko wrote:
I believe the unsafe aspect of the system is the lack of training in
modern curriculums and our lack of practice with the equipment.

This reminded me of a useful training aid that I've put together
some time ago. It is a known fact that any AM radio station can
serve as a radio beacon that an ADF can be tuned to. AM radio
stations are everywhere, unlike real NDB transmitters, and they are
just as good for practicing NDB work as any NDB. So, I have
downloaded a list of AM-transmitting antenna from FCC, along with
their lat/lon, callsign, and output power, and transformed it into
a google-earth file. Then I zoomed-in on the area of my interest
in google-earth, and printed the map with the stations. Very handy
for NDB practice. Here's a link to the google-earth file containing
all AM-transmitting antenna within 1000km radius of NYC:
http://tinyurl.com/35rdez
If anyone wants such a file for some other part of the US, just let
me know, and I'll generate it and put it online.

The only problem I have with trying to use a MW AM radio station for
navigation is that they don't have consistent power and radiation
patterns. Typically they'll broadcast a reasonably strong signal during
the day. However at night, because the ionospheric absorption goes down
and because the signal can skip, the FCC requires most stations to dial
their power back and change antenna patterns.

This can result in a sudden loss of signal when the sun sets. I would
advise anyone looking for NDB practice to avoid the evening hours, and
not to navigate with AM stations in actual IMC conditions unless you're
very familiar with the radiation pattern and power output of the station
you're using. Remember, AM radio stations no longer report service
outages via NOTAM, so you're pretty much on your own here.

Jake Brodsky