de WB2CPN South Central Pennsylvania 2002.04.18 When I was with AT&T, both old and new, high quality shielded pair was used for local baseband video and multiplexed carrier systems. Impedance was 124 Ohms. Frequencies up to approximately 9 MHz were used. Of course, they had plenty of equalizers and amplifiers to make it flat with unity gain. I think RS's cable has less loss... 73 Clete