[Elecraft] Question - for Educational Purposes

[Lyle Johnson]

> I've been doing some reading on the new firmware.  I would like someone to explain (like I am a 3rd Grader) the different between IIR Filtering and FIR Filtering.  Thanks.

Essentially, IIR filters have feedback, so they can ring and in extreme 
cases oscillate.  Think of an op-amp based audio filter, for example -- 
or a regenerative receiver.

FIR filters have no feedback, so they cannot ring or oscillate.  These 
filters are generally impractical to implement outside of DSP.

For a clear, readable explanation see Experimental Methods in RF Design 
(EMRFD).  If you have only one technical book in your library, it should 
be EMRFD in my opinion.  Available from many places, including Elecraft :-)

For more details and links while your copy of EMRFD arrives in the mail, 
see < URL:http://en.wikipedia.org/wiki/IIR >

73,

Lyle KK7P