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--- howto:hambasics:sections:practice [2020/10/24 16:59] – va7fi
+++ howto:hambasics:sections:practice [2020/12/30 09:08] (current) – va7fi
@@ Line 51: / Line 51: @@
   * A filter that lets high frequencies through but blocks low frequencies is called a //high pass// filter.
   * A filter that lets low frequencies through but blocks high frequencies is called a //low pass// filter.
-  * Combining a high pass and low pass filter we get a //band pass// filter, which lets audio between two frequencies.
+  * Combining a high pass and low pass filter we get a //band pass// filter, which lets audio between two frequencies.  The narrower the bandwidth of the mode we use, the narrower the band pass filter we can use to clean up the audio.  For example:
+    * An SSB voice signal can use a 2.4 kHz filter where as
+    * A CW signal can use a much narrower 250 Hz filter.
   * The "inverse" of a band pass filter is called a //notch// filter.  It blocks a narrow band of frequencies in the middle of the audio spectrum.  Here's an example:
@@ Line 70: / Line 72: @@
 ===== Stability =====
+This is the ability of a receiver to stay on the right frequency and not //drift//.
 ====== Transmitters ======
@@ Line 76: / Line 78: @@
-======= Questions =======
+====== Questions ======
   * B-003-010-001 -> B-003-011-001
-[[stationassembly |{{/back.png }}]] [[..:section|{{  /next.png}}]]
+[[stationassembly |{{/back.png }}]] [[electronics|{{  /next.png}}]]