[Elecraft] How do you measure filter offset [K3]

[Mike Scott]

>I beg to differ. Based on rather careful measurements, my 400 Hz 
>8-pole filter needs an offset of .045 to center it with the DSP 
>filters.

I don't understand what the filter offset is really doing. My 2.7 KHz filter
for example is -0.87. I assume this means 870 Hz offset from something. What
reference is the offset from? Does this mean that the IF frequency is
actually shifted from some nominal value?

Could someone explain a method of measuring roofing filter offset? I have
spectrum analysis software. Soon [I hope] I will have the second receiver
and I will possibly be setting up a compromise offset for two filters. I
paid a little extra for matching filters but it would be good to do some
measuring.


Mike Scott - AE6WA
Tarzana, CA (DM04 / near LA)
K3-100 #508/ KX1  #1311