=====ETA313-03: Theory lesson 2: Electric Circuits=====

[[user:kurser:ham_vt2024|Back to course information]]

**Recommended reading: KonCEPT page 84-144 (chapter 3)**

Draw a superheterodyne TRX on the black board. Including antennas and propagation. 

Explain from TX to RX
  * DAC which stands for Digital to Analog converter. 
    * Audio BW: 300-3000 Hz
  * Pulse shape filter (LP)
    * Show other filter symbols
  * Mixer -> BP filter
  * Oscillator
  * Amplifier
  * Mixer -> BP filter
  * Oscillator + Frequency multiplier
  * Power amplifier (PA)
  * Antenna


  * Antenna
  * Low noise amplifier
  * The rest of the superheterodyne receiver 
  * ADC which stands for Analog to Digital converter

Explain what is heterodyne/homodyne

Direct converting (DDS) radio and direct sampling. 

Mention the SDR lab. Ask if people can bring own SDR or radios. 

https://sk6ag.org/sdr-mottagare/