[Premium-Rx] Group delay in the IF

[Terry O'Laughlin]

There a little RF engineering firm, LS Research, in Cedarburg, Wisconsin 
that designed a line of FM receivers for Proton featuring IFs designed for 
minimal group delay.  They were marketed as "Schotz tuners" (after the 
founder, Larry Schotz).  I had one and it was noticeably cleaner and seemed 
less susceptible to multipath when on the move.  But that was FM, where I 
think phase anomalies are a little more critical than AM or SSB.

Terry O'



At 07:33 AM 10/8/2003 +1000, you wrote:
>Interesting that no-one has mentioned the IF filter group delay or PHASE
>RESPONSE!
>
>I think you will find this is responsible for many of the effects described
>qualitatively by others here. For example, the amount of ringing exhibited
>by a filter is a function of its phase response. When a receiver is used for
>data reception, linear phase response (ie. flat group delay) is what it is
>all about.