IF amplifier design

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froten

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Hello All,

I'm trying to build a multistage (3 stages) 455KHz IF amplifier. The circuit is a common emitter with primary tuned transformer on the collector. I can not get IF transformers so I have to build them by my self. I have a big problem to design the transformer as follows:
1) What L & C should I use for the primary side for 455KHz?
2) What L should I use for the secandary side?if the next stage input impedance is 3.3K for example.
3) What is the turns ratio should I use? if the next stage input impedance is 3.3K for example.

I realy have seriose problem with selection of L&C and N. Any help is greatly appreciated.
 
Consider using ceramic filters instead. (Murata and Toko)

Typical input and output terminations for ceramic filters is 1.5k to 2k ohms. You can pretty much make the collector load resistor 1.5k ohms for filter input termination. You can set the current in the input stage to create the proper ceramic filter load termination.

No coil to deal with.
 

Here is a useful reference:
if amplifier transformers
 
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