05-25-2008, 09:25 AM
They attempted to 'tune' this bypass arrangement for the most effective bypassing at the IF frequency. Some of the older paper caps showed resonance on other frequencies because of their internal construction and didn't perform well at 455 so the goal was to tune that back down to 455.
Modern caps are not particularly known for this problem so the coil can be omitted. Unless you just want it there for looks but then you theoretically run the possibility of recreating the original problem unless you know the internal inductance of the new cap and can calculate it in accordingly.
-Bill
Modern caps are not particularly known for this problem so the coil can be omitted. Unless you just want it there for looks but then you theoretically run the possibility of recreating the original problem unless you know the internal inductance of the new cap and can calculate it in accordingly.
-Bill
