Search results
Results From The WOW.Com Content Network
Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by law enforcement and in citizens band (CB) radio transmissions. The police version of ten-codes is officially known as the APCO Project 14 Aural Brevity Code. [1]
The 10-meter band is a portion of the shortwave radio spectrum internationally allocated to amateur radio and amateur satellite use on a primary basis. The band consists of frequencies stretching from 28.000 to 29.700 MHz.
Signal strength and readability report. A signal strength and readability report is a standardized format for reporting the strength of the radio signal and the readability (quality) of the radiotelephone (voice) or radiotelegraph (Morse code) signal transmitted by another station as received at the reporting station's location and by their ...
A plain-language radio check is the means of requesting and giving a signal strength and readability report for radiotelephony (voice) communications, and is the direct equivalent to the QSA and QRK code used to give the same report in radiotelegraph ( Morse code) communications.
A police code is a brevity code, usually numerical or alphanumerical, used to transmit information between law enforcement over police radio systems in the United States. Examples of police codes include " 10 codes " (such as 10-4 for "okay" or "acknowledged"—sometimes written X4 or X-4), signals, incident codes, response codes , or other ...
10-meter beacons. Most high frequency radio propagation beacons are found in the 10-meter band (28 MHz), where they are good indicators of Sporadic E ionospheric propagation. According to IARU bandplans, the following 28 MHz frequencies are allocated to radio propagation beacons: IARU Region. Beacon Sub-bands (MHz)
Acquiring a signal is the process of determining the frequency and code phase (both relative to receiver time) when it was previously unknown. Code phase must be determined within an accuracy that depends on the receiver design (especially the tracking loop); 0.5 times the duration of code chips (approx. 0.489 μs) is a representative value.
Rolling code. A rolling code (or sometimes called a hopping code) is used in keyless entry systems to prevent a simple form of replay attack, where an eavesdropper records the transmission and replays it at a later time to cause the receiver to 'unlock'. Such systems are typical in garage door openers and keyless car entry systems.
The following equation gives the frequency f (Hz) of the n th key on the idealized standard piano with the 49th key tuned to A 4 at 440 Hz: f ( n ) = ( 2 12 ) n − 49 × 440 Hz = 2 n − 49 12 × 440 Hz {\displaystyle f(n)=\left({\sqrt[{12}]{2}}\,\right)^{n-49}\times 440\,{\text{Hz}}\,=2^{\frac {n-49}{12}}\times 440\,{\text{Hz}}\,}
In information theory, a low-density parity-check (LDPC) code is a linear error correcting code, a method of transmitting a message over a noisy transmission channel. [1] [2] An LDPC code is constructed using a sparse Tanner graph (subclass of the bipartite graph ). [3]