The EM-7842 Tunable Notch Filter Network is a tunable narrowband rejection filter operating from 15 MHz to 100 MHz. It is used whenever high rejection (attenuation) is required at one select frequency and low attenuation for the other frequencies. The high power rating of the EM-7842 permits its use for measurements on high power transmitters, providing the voltage input level is carefully regulated.

The EM-7842 covers from 15 MHz to 100 MHz in two (2) frequency bands using a variable capacitor and resistor plus two (2) interchangeable fixed inductance tuning coils. The tuning coils are stored in a separate carrying case when not in use. The tuning coil selected is inserted into the internal circuitry of the EM-7842 through the removable top cover of the unit.

The EM-7842 is designed for bench top operation.