[DARARepeater] Three leg voltage regulators

[kb8stb]

We were discussing adding a regulator to each of our  display MOSFET boards....
Just saw this message posted to the repeater builder forums and figured it applied to us...
I'm sure some of you already know this and tried to explain it to the rest of us, but sometimes it's easier to understand in print...
My standard practice when using any of those regulators is a 0.1 uF on the input to ground, & 0.33 uF on the output, both directly soldered to the regulator pins, or right next to the device if mounted to a PC board.



BTW some manufacturers specifically caution against using low ESR ceramic capacitors on those regulators.  It seems counterintuitive, but some of those older regulators like the LM340-x & 78xx series were never designed for such low ESR bypass capacitors, & in fact if used with them can break into some nasty oscillations that even 10 uF of milliohm-ESR capacitance can't squelch.  I keep a bin of 0.1 & 0.33 uF tantalum capacitors specifically for this application.



Bob NO6B 



         

          
  
     


  
  
    
 
     
       

Just throwing it out there for consideration..
KB8STB
Steve
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