I have an RC, prior to 1986. I received a new cable box today. The cable going from tv (cable in) to cable box (cable out) will not fit properly into the cable out on the cable box (loosely fits). My RCA is not a hdtv. The cable I was given at our local store was Xfinity Cisco RNG 100. I was told by tech (via phone) to get either DUCT 700 or DCT 652 or DCH 3416. I was told at the local store that the Cisco box was all they had available.
You can't have Motorola boxes on a Cisco powered system which is those models you listed. Your only choice is that Cisco RNG100 or a older Scientific Atlanta box.
There is no reason that the RNG100 can't hook up to your RCA TV, you would either be using a yellow / red / white composite video cable, or the older coax cable that twists onto the back of the cable box's threaded output port.
You should either be using ports # 5 and 6 for a composite video cable, or port # 11 for a coax cable that twists on. You might need to get a new coax cable from the box to the TV, which you can get at the Comcast office.
From your reply, it appears that I need a new coax cable running from the tv to the set-up box. Will there be a charge for this cable? Will they know which one I will need or do I need to ask for a specific kind. The one I haven now has the push in ends w/ pin.
Additionalliy. the phone tech told me to get one of the three set-up boxes. I did not know they were for a Motorola. He never asked about my tv brand name. Thank you so much for your quick reply. It is truly appreciated.
I won't have to stand in line long at Comast....beautiful new office...and fast service when I was there yesterday. I'll pick one up at Comcast. I do have the Service Protection Plan but not sure if it would cover a tech coming to house and delivering proper coax cable and setting up my tv, etc., for me.. I do believe I can do it myself after picking up the cable or I can just contact one of you and get the help I need over the phone or online.