Re: How to design crystal filter using NANOVNA #nano #filters

iz oos
 

A few months ago I tested a nice 10.7 Mhz crystal filter I bought years ago. Most likely I did damage it with a 7dbm dds, but I cannot remember exactly. Testing using an attenuator and Antuino in SNA mode it was clear there was something wrong in the shape and insertion loss. I dismantled it, it contained a tuned coil at the input and one on the output. I tested each of the 4 crystals inside, three looked absolutely fine but one was clearly jeopardising the whole filter. You can also start practicing testing each crystal, then see what changes adding similar crystals in series or in parallel and then matching the input and the output with a small transformer or a LC circuit. Learning on books is fine, but practicing in your own way is even better. That's my two cents.


Il 05/apr/2020 23:26, <ashok.das81@...> ha scritto:
Hi all,
Can anyone guide me how to use VNA to design crystal filter. I am completely new to this VNA. Many forums mention this abt VNA and crystal filter but i cannot find any proper guide how to design crystal filter using VNA. I will use NANO VNA

Regards
Ashok 

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