From QRZ.Com, the Icom handout, and Part 97 Of The FCC Rules -
Ham Radio Glossary - An overview of amateur radio terms.

National Radio Quiet Zone
The area in Maryland, Virginia and West Virginia bounded by 39 degrees
15' N on the north, 78 degrees 30' W on the east, 37 degrees 30' N on the
south and 80 degrees 30' W on the west.

NB
Noise Blanker. A function reducing pulse-type noises.

NCO
Net Control Operator. The individual running an amateur radio net,
persuant to FCC Rules, and to "keep control". Also see Net.

NCS
Net Control Station.
See Net Control Operator

Net
From the term "network", it means a gathering of amateur radio operators
on a certain frequency/mode for such things as a roundtable discussion
on a wide variety of topics, for handling message traffic, or emergency communications.

NiCd
Or "Ni-Cad"; "Nickel Cadmium". A type of rechargable battery commonly used
with radio equipment. These tend to have a "battery memory effect"...where
if you fail to discharge these completely before recharging, your usage
time will be considerably less than otherwise noted.

NiMH
"Nickel Metal Hydride"
A type of rechargable battery commonly used with radio equipment. Like the Ni-Cd, these tend to have a "battery memory effect"...where if you fail to discharge these completely before recharging, your usage will be
considerably less than otherwise noted.

N-P Junction
See "P-N Junction".

NOAA Weather Radio
Operated by the National Oceanic And Atmospheric Administration from
162.40 to 162.55 Mhz on the Public Service band, NOAA Weather Radio
transmits weather forecasts, observations, advisories, watches, and
warnings, 24 hours a day, from the area National Weather Service
office. Weather alert radios sound an alarm whenever certain weather
watches or warnings are issued...usually for severe weather.

Notch filter
Sharp and narrow rejection filter for elimination of interfering signals.

Novice
Originally the entry level license for U.S. amateur radio license, this
license has the fewest privileges of any amateur radio class license.
While no longer issued, Novice class licensees may use their license
privleges, and renew them at the appopriate time. They have the same
HF privileges as Technician Class licensees, plus limited privileges
on the 1.25 meters and 33 centimter band.

NPN
See "P-N Junction".

NR
Noise Reduction. DSP feature reduces unwanted signal noise.

NTS
"National Traffic System". Please see http://www.weca.org/nts.html for
more information.
--- SBBSecho 3.20-Win32
* Origin: The Thunderbolt BBS - Little Rock, Arkansas (954:895/7)