Tuesday 22 February 2011

HAM BAND VFO

 

Variable frequency oscillator uses two numbers of BC548. For 40 meter band VFO oscillates form 2.567 MHz to 2.667 MHz which on mixing with 4.43 MHz generates 7.0 MHz to 7.1 MHz. If you have a frequency meter it is easy to calibrate the VFO, otherwise connect a 2J gang condenser in parallel with VFO coil and adjust it to receive ham stations. VFO is fixed inside a small aluminum box.

VFO - Variable frequency oscillator

1 comment:

  1. What are the values of two caps connected to the base of 1st transister?

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