> I have 2 C-Series bandpass cavities, with individual I.L. set
> at 1.0 db each. When I couple them together and measure, I
> get a total I.L. of 2.9 db. I should see something like 2.1
> or 2.2. I have measured the coupling cable and see < .1 db,
> so the cable is good. Anyone have an idea why the loss is so
> high when coupled?
Most likely they aren't tuned correctly for maximum return loss, and when
you cascade them, the resonant frequency is no longer where you thought it
was (i.e. a "detuning" effect). Have you measured the return loss of the
cavities individually?
--- Jeff WN3A
