Lines Matching +full:signal +full:- +full:to +full:- +full:noise
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11 <img src="pic/radio2.jpg" alt="jpg" align="left">ICOM R-72 shortwave receiver and Sure audio mixer
13 <!-- #BeginDate format:En2m -->11-Sep-2010 05:55<!-- #EndDate -->
27 …to an audio signal, rather than a serial timecode and communications port or special purpose bus p…
28 <p>All three drivers make ample use of sophisticated digital signal processing
29 algorithms designed to efficiently extract timing signals from noise and interference.
31 and decoding techniques, including maximum-likelihood and soft-decision methods.
32 The documentation page for each driver contains an in-depth discussion on
36 …to groom input signals, suppress spikes and normalize signal levels. An automatic gain control (AG…
37 …to the audio signal as received. This is done by stuffing or slipping samples as required to maint…
38 …to select the input port and to monitor the input signal. The <tt>fudge flag 2</tt> command select…
40 …- speaker or headphone jack - connected to either the microphone or line-in port on the computer. …
41 …signal is the antenna. It need not be long - even 15 feet is enough if it is located outside of a …
42 …an also be used to power the radio. A couple of center-tapped audio transformers will minimize noi…
43 …to the receiver location at any given hour. While both drivers support the ICOM CI-V radio interfa…
44 <p>Shortwave (3-30 MHz) radio propagation phenomena are well known to shortwave enthusiasts. The ph…
48 after sunrise and sunset at the midpoint of the path from transmitter to
50 …<li>Ambient noise (static) on the lower frequencies follows the thunderstorm season, so is higher …
52 …<li>The optimum frequencies are higher at the peak of the 11-year sunspot cycle and lower at the t…
54 <p>The best way to choose a frequency is to listen at various times over the day and determine the …
56 …nt disables the CI-V interface. Since all ICOM select codes are less than 128, the high order bit …
156 …to help hook up the audio signals and monitor the driver operations. The documentation page for ea…
157 <p>Connecting radios and IRIG devices to the computer and verifying correct
158 configuration is somewhat of a black art. The signals have to be connected
159 to the correct ports and the signal level maintained within tolerances. Some
160 radios have recorder outputs which produce a microphone-level signal not affected
161 by the volume control. These signals can be connected to the microphone port
163 headphone or speaker output to the line-in port and adjust the volume control
165 level somewhere in the middle of the range 0-255. IRIG signals are usually
166 much larger than radio outputs, usually in the range to several volts and
167 may even overload the line-in port. In such cases the signal is designed to
168 drive a cable terminated with a 50-ohm resistor, which results in a level
169 the line-in port can handle..</p>
170 <p>It is very easy to underdriven or overdrive the audio codec, in which case
171 the drivers will not synchronize to the signal. The drivers use <tt>fudge
172 flag2</tt> to enable audio monitoring of the input signal. This is useful
173 during setup to confirm the signal is actually reaching the audio
174 codec and generally free of noise and interference. Note that the monitor
176 …to the <tt>clockstats</tt> file each time the clock is set or verified and at other times if verbo…