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howto:hambasics:b003

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howto:hambasics:b003 [2020/02/01 18:54] – [Transmitters] va7fihowto:hambasics:b003 [2020/02/20 19:04] – [Transmitters] va7fi
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   * The **speech amplifier** increases the strength of the baseband signal before it can modulate the carrier.    * The **speech amplifier** increases the strength of the baseband signal before it can modulate the carrier. 
   * The **RF oscillator** generates a stable sine wave signal at the rest frequency. Note that the oscillator frequency can be much lower than the final transmitted frequency.    * The **RF oscillator** generates a stable sine wave signal at the rest frequency. Note that the oscillator frequency can be much lower than the final transmitted frequency. 
-  * The outputs of the speech amplifier and the RF oscillator are mixed together in the **balanced modulator**. This produces different modulated frequencies, only one of which is kept. +  * The outputs of the speech amplifier and the RF oscillator are mixed together in the **balanced modulator**. This produces a signal with two side bands, only one of which we want to keep. 
-  * The **filter** blocks the extra frequencies produced by the modulator and lets only the one we want through. +  * The **filter** only lets one sideband through. 
-  * The **VFO** +  * The **VFO** creates a sine wave frequency that can be varied. 
-  * The **mixer**+  * The **mixer** uses the output from the filter and the VFO to generate a higher frequency signal.
   * The **linear amplifier** increases the power of the signal to be transmitted by the antenna.   * The **linear amplifier** increases the power of the signal to be transmitted by the antenna.
 +
 +<WRAP important center round 80%>
 +Note that a [[wp>Frequency_mixer |Frequency Mixer]] //multiplies// two signals together, which usually results in a total of four (or more) frequencies.  This is not to be confused with an [[wp>Mixing_console |Audio Mixer]], which //adds// different signals together.  See the optional [[wavemodulationmath#mixer | Wave Modulation Math page]] for more details.
 +</WRAP>
  
 ===== Receivers ===== ===== Receivers =====
- 
-==== SSB/CW Receiver ==== 
-{{ :howto:hambasics:3_5.png }} 
- 
  
 ==== FM Receiver ==== ==== FM Receiver ====
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   * The **audio amplifier** increases the strength of the baseband signal before passing it to the speaker.   * The **audio amplifier** increases the strength of the baseband signal before passing it to the speaker.
  
 +
 +
 +==== SSB/CW Receiver ====
 +{{ :howto:hambasics:3_5.png }}
  
 ===== Digital System ===== ===== Digital System =====