Re: Variable uBitx IF bandwidth question

richcarter03052 <re.carter@...>
 

As I've posted elsewhere, I built a K2 a few years back.  It has a variable bandwidth IF filter that looks kind of similar to the ladder filter in the uBitx.  Each node has a 100k pull-up resistor and variable capacitor diode (1sv149).  Voltage to the pull-up resistor can be varied under processor control.  I honestly don't know enough about filter design to have an opinion regarding how hard it would be to adapt the uBitx to add this feature.  One would think that instead of using an output pin from the processor, a variable resistor or selector switch with different series resistors might work.  
http://folk.uio.no/sverre/LA3ZA/blog/K2/2005_K2_Schematics.pdf

Rich - KE1EV

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