locked Re: Measuring and matching 10.7 MHz ceramic filters


This is a standard Murata 280 kHz filter swept with 404 points (4 segments). The total span is 600 kHz, centered at 10.7 MHz. Group delay is below. 
I did a right click and adjusted the group delay Y axis amplitude min and max settings. This is helpful to compare different types of filters, which is difficult using the default "autoscale"
Also - there are two plots shown. The first one is in blue, it was taken first, then used "set current as reference". I then removed the 10 pf cap, and did another sweep. 
The darker black line shows the effect of removing the Murata recommended 10pf cap on the output. The group delay actually looks flatter. The response curve shifts slightly to the left when 10pf is removed. 

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