In general, in one aspect, the disclosure describes a resonance restricting material in communication with a bypass line of a cable television tap. The bypass line generates resonances at a defined frequency in response to RF parameters in the tap and the resonances increase insertion losses at the defined frequency and precludes bandwidth of the tap being increased above the defined frequency. The resonance restricting material may attenuate the resonances generated by the bypass line at the defined frequency (e.g., approximately 1.2 GHz) and reduce insertion losses at the defined frequency and enable the bandwidth of the tap to be increased (e.g., from 1.0 GHz to 1.5 GHz).