The DVR goes to a modulator that uses channel 87. This is then fed to a Eagle Aspen 2x1 combiner. The other leg of the combiner has the cable feed. The output of the combiner feeds a small amp then goes to a 1x8 splitter for 8 tvs in the house.
If you unhook the DVR feed at the combiner the Cable feed looks good. If you unhook the Cable feed at the combiner the DVR feed looks good.
Thanks