I need either a 45MHz or 455kHz filter with 2.8/3kHz bandwidth for purposes of improving SSB selectivity. Less than or equal to 1db ripple, insertion loss less than or equal to 4db. Kindly help me arrange any filter with these specifications. I will order in bulk amount and for many years.
We do not have any filters which meet all of your specifications. It looks like as one comes close to meeting one spec, the others tend to get further away. Therefore, you may have to compromise one or more specs to get something functional.
Here are the ones that come closest:
Note that the 45MHz filters have bandwidths of 10kHz to 30kHz, which, considering that their center frequency is 100x higher, is far better than the bandwidth you specify for the 455kHz filters.