Transko Monolithic Crystal Filter (MCF) UM-5 case

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This is a model of an Transko Monolithic Crystal Filter (MCF) with a UM-5 thru-hole PCB case type.Monolithic Crystal Filters are typically used after the first RF mixer to filter out the Intermediate Frequency (IF) down-converting to standard frequencies such as 21.4 MHz and 45 MHz. [NOTE : for 10.7 MHz, see UM-1 or HC-49/U case sizes]However there are lesser known Crystal Filter frequencies supported as well.The filter selectivity is based upon the bandwidth and can be as loose as 16 KHz or as tight as 3.75 KHz. This is important for meeting frequency channel spacing requirements.There are also options for the number of poles which determine how much noise if filtered out of the crystal filter. Generally the more poles, the more noise is removed for a better Signal to Noise ratio (S/N).