philips dvdr985

I need to know if I can use the RF in and out to record from my cable box and send the recorded content back to my analog tv again using the RE out. This is what was done before the advent of the cable box. If not do I need to use the box's a/v out to the units a/v in? And then a/v out to a modulators a/v in and the mods RF out to the tv? I have 4 dvd recorder/vcr combo units. 2 allow the RF connections. 2 require a modulator. The RF are only pass throughs, not active. The manual shows the RF connections but do not mention whether they are active or passive. No mention is made of modulators. I do not know if this unit is designed any differently than my previous unit. Cannot tell from the listing. Any advice welcome.