When a CATV converter box is required at each television location but does not have unused channels available for modulated ChannelPlus channels, a cable box combiner kit, Model C-BCK is needed. The Model C-BCK Cable Box Combiner Kit allows the CATV box to be tuned to all normal CATV channels; these are viewed when the television is tuned to channel 3. The modulated channels are viewed when the television is tuned to the ChannelPlus modulator channel numbers. The Model C-BCK cable box combiner kit includes a high-pass filter, two 2-way splitter/combiners and two 6-inch coaxial cables.