Author Topic: Bandpass filters out of metal tubes? (Bird electronics)  (Read 1262 times)

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Offline Phil1977Topic starter

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Bandpass filters out of metal tubes? (Bird electronics)
« on: July 15, 2024, 08:29:44 pm »
Hi,

I was wondering how the bandpass filters shown in this video are working:



I have no need to know it, I´m just curious. I can roughly imagine how a waveguide works, but just have no idea how a set of tubes creates a well defined and mostly flat frequency response.

 

Offline madires

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Re: Bandpass filters out of metal tubes? (Bird electronics)
« Reply #1 on: July 15, 2024, 10:17:28 pm »
They are called stub filters. When the stub is lambda/4 long and reflects the wave you'll get a lambda/2 delay (180° phase shift).
 
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Offline Phil1977Topic starter

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Re: Bandpass filters out of metal tubes? (Bird electronics)
« Reply #2 on: July 16, 2024, 04:45:07 am »
Thank you madires, that wording leads to the right explanations!  :clap:
 


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