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IrishrepublicanArmy's definitions

ADF

Automatic Direction Finder
or
Automatic Direction Finding System

a navagation system used by aircraft and sea-going ships. It consists of one or more ground stations that transmit a signal in the 225 to 500 kHz (.225 to .500 MHz) range. Because of the low-frequnecy of these signals, their range is very good and not limited by the line-of-sight range of the VOR system. The recevier in the airplane/boat uses a loop antenna to "home-in" on the station. There is also a long-wire receiving antenna installed on many aircraft. Most ADF receivers can also recieve the AM broadcast band (530 to 1710 kHz) so pilots can also home in on powerful broadcast stations.

ADF signals should not be used in thunderstorms because the high amount of electro-magnetic interferance that lightening causes.

Many pilots can't even use the ADF system, which is a shame, becuase of better systems such as VOR and the GPS systems.
"In most of the third world, the ADF navigation system is the only way to go"
by IrishRepublicanArmy October 21, 2003
mugGet the ADFmug.

PRC-77

the PRC doesn't stand for anything.

the PRC-77 (and the improved PRC-770) are military VHF FM transcievers, that have been used sence 1960, and are slowly being phased out because the US Army likes them.

Frequency Coverage:
30.0000 to 76.0000 MHz
channel spacing:
50 kHz
channels:
920
Power Output:
5 watts
Range:
10 miles on a bad day
5 miles when the VC are shooting at you
30 miles when you get back to base

PRC-77s are used as manpack radios (straped to the back of GIs and used for unit-to-unit communications), if you've ever seen the movie "Platoon", the PRC-77 is the radio that all the Americans are carrying on thier backs.
or they are installed as radios in Humvees and tanks. (i.e. all the antennas on military viecles are connected to PRC-77s.

widly copied by every NATO member, so all the good guys can talk to each other.
"Roger, get the PRC-77 on 41.75 and call HQ"
by IrishRepublicanArmy October 21, 2003
mugGet the PRC-77mug.

PSK31

A digital transmission mode -- Phase Shift keying with 31.25 baud rate
PSK31 is one of the better HF operating digital modes.
by IrishRepublicanArmy January 1, 2004
mugGet the PSK31mug.

lightbulb

Electric lamp consisting of a glass bulb containing a wire filament (usually tungsten) that emits light when heated.
Geek One: What do you do in your free time?

Geek Two: Change lightbulbs!
by IrishRepublicanArmy January 27, 2004
mugGet the lightbulbmug.

NSA

see also Big Brother and 1984.

They listen to every radio transmission/telephone call/ etc. etc.
If it's got an antenna attached to it, the NSA is listening
by IrishRepublicanArmy November 13, 2003
mugGet the NSAmug.

radar mile

The time required for a radar pulse to travel 1 mile (~1.6 km) to an object, i.e., to a target; reflect; and return to the receiver. Note: A radar statute mile is approximately 10.8 ms (microseconds); a radar nautical mile is approximately 12.4 s. The time for any other radar unit distance is readily determined, such as the radar meter or the radar kilometer. NTIA
I listen to propagation mapping radar on the 27 MHz freeband.
by IrishRepublicanArmy January 24, 2004
mugGet the radar milemug.

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