Late comment on an old video. But that thing is measuring as if there is something really wrong with it. Cavity filters should only have a few DB of insertion loss and have a much lower return loss. My guess is that one of the coupling loops is broken.
Hmm maybe a connector with a bad contact? I have no intuition for insertion loss on cavity filters so didn't notice it might be broken, but I can't see broken loops from the video at least. Maybe I'll take another look inside it someday. Not sure where it's gotten off to, but the insight of a "simple tailor" is appreciated good sir.
Do you know of a good resource that talks about how to design these? Most of the microwave engineering textbooks that I have found contain only a few paragraphs on cavity resonators.
Most likely reason for the mismatch and variation in insertion loss is that the coupling probes don't scale as you tune the cavity.
Late comment on an old video. But that thing is measuring as if there is something really wrong with it. Cavity filters should only have a few DB of insertion loss and have a much lower return loss. My guess is that one of the coupling loops is broken.
Hmm maybe a connector with a bad contact? I have no intuition for insertion loss on cavity filters so didn't notice it might be broken, but I can't see broken loops from the video at least. Maybe I'll take another look inside it someday. Not sure where it's gotten off to, but the insight of a "simple tailor" is appreciated good sir.
Wow 😮 that is so cool! 😃👍
Interesting ..... always wonder how using a transmitting tube like the 2c39 this cavity is put on top of the anode ..... and still works ....
What is the name of the manufacturer and p/n of this filter?
Do you know of a good resource that talks about how to design these? Most of the microwave engineering textbooks that I have found contain only a few paragraphs on cavity resonators.
wonder if you could use this thing for frequency modulation slope detection across this frequency band?