We were required to deliver 0 dBmv at the end of 100 feet of RG-59 or RG-6 for two sets per the franchise. The system was designed at +10 dBmv at the tap to allow for three or four TVs at the 100 foot range. That was on a 36 channel system with RCA modulators & HST. It was done for two reasons. To have a little extra signal available when the system was built, and for conversion for a 300 MHz plant to a 450 MHz plant without respacing the trunk amplifiers.
I build a headend & interface to tie two incompatible community loops together. Ours was a sub split loop, and the other CATV company used mid split. We used 2 & 12 for pilots, so we fed them Channel 2 into their return, and down converted their feed to T-9 for our return. That headend had two RCA HSP and a combiner. The interface was another HSP in a large stainless steel NEMA box mounted to a power pole at the boundary of the two systems. A pair of two way splitters were used to route the signals between the systems, as well as into and out of the HSP. The other company wanted us to install a modulator and a demodulator at the boundary to give us audio & video, and another pair from our side so the interface would be baseband. Their design was over $15,000 in hardware alone. My design was under $3000 for all the hardware & labor to install. I had system designers from both sides telling me it wouldn't work, but it did the job with no problems. :)