IF selectivity

[ozaiobee]

In a heterodyne receiver, does the 1st IF stage has to be wider than the second stage? Basically in IF selectivity for receivers, are the IF stages require to be designed so that the stages are decreasing in bandwidth? If they don’t please explain why?

 

[IRstuff]

Why do you think otherwise?

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[VEBill]

It wouldn't make much sense to have a wider filter following a narrow filter.

 

[Skogsgurra]

The thinking may come from the staggered tuning that once was used to produce IF stages with steep cut-off but enough BW to let music through in old AM heterodynes.

Long time that I haven't been close to RF/IF - is that technique still used?

Gunnar Englund

http://www.gke.org

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