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howto:hambasics:b003 [2019/12/17 19:50] – [Transmitters] va7fihowto:hambasics:b003 [2020/02/20 19:04] – [Transmitters] va7fi
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 +|<100% ----- >|
 +|  [[home |Ham Basics]]  |  [[test |About The Test]]  |  [[Reference |References]]  ^  [[sections |Study Sections]]  |
 +
 <WRAP round todo center box 60%> <WRAP round todo center box 60%>
  **Under Construction**: VA7FI is editing this section, please do not edit it until this notice is taken down.  **Under Construction**: VA7FI is editing this section, please do not edit it until this notice is taken down.
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 ===== Block Diagrams ===== ===== Block Diagrams =====
-The next few sections use block diagram to illustrate the construction of various pieces of equipment.  Here's an excellent introduction that should help with what follows:+The next few sections use block diagrams to illustrate the configuration of various pieces of equipment.  Here's an excellent introduction that should help with what follows:
  
 {{ youtube>3VXnhIeeT6c }} {{ youtube>3VXnhIeeT6c }}
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 {{ :howto:hambasics:3_4.png }} {{ :howto:hambasics:3_4.png }}
  
 +  * The **master oscillator** generates a stable sine wave signal at the rest frequency.
 +  * The **driver / buffer** is the first stage in the amplification process.
 +  * The **key** is basically an on/off switch used to let the signal through to the amplifier or block it.
 +  * The **power amplifier** is the last stage of amplification before the signal is released to the antenna.
  
-==== FM Transmitter ==== 
  
 +==== FM Transmitter ====
 {{ :howto:hambasics:3_2.png }} {{ :howto:hambasics:3_2.png }}
  
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 {{ :howto:hambasics:3_6.png }} {{ :howto:hambasics:3_6.png }}
  
 +  * The **microphone** picks up the sound waves carried by the air and converts them into a weak electrical signal that becomes the //baseband//.
 +  * 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 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** only lets one sideband through.
 +  * The **VFO** creates a sine wave frequency that can be varied.
 +  * 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.
 +
 +<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 =====
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   * The **frequency discriminator** extracts the baseband signal.   * The **frequency discriminator** extracts the baseband signal.
   * 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 ==== ==== SSB/CW Receiver ====
 {{ :howto:hambasics:3_5.png }} {{ :howto:hambasics:3_5.png }}
- 
- 
  
 ===== Digital System ===== ===== Digital System =====
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   * B-003-001-001 -> B-003-003-010   * B-003-001-001 -> B-003-003-010
  
-[[sections |{{/back.png }}]] [[waveinterference |{{  /next.png}}]]+[[propagation |{{/back.png }}]] [[section |{{  /next.png}}]]