davepusey said:
Morse code is sent as a tone burst of a specific frequency (usally 1khz but it varies depending on the sender's equipement). Some of the transmissions we receive are rather noisy and therefore if a band pass filter could just allow the morse tone frequency to pass through and remove all the background noise then that would be great!
Well it's taken a long time, but you've finally mentioned what you want!.
It's an extremely common device, used by radio amateurs for that exact purpose - you don't need variable frequency or bandwidth, just a sharply tuned filter at about 1KHz. Morse code is transmitted as CW (carrier wave), the actual tone you hear is generated in the receiver itself (by the beat between the incoming signal and a 'carrier insertion oscillator'). So you tune the radio to match your filter.
Try looking on amateur radio sites, I've seen hundreds of projects in magazines over the years.