To combine 2 dishes and send to 2 receivers, you will need a switch. Diplexers won't work. HD and SD will be combined in the same cable by the switch, but you will need a separate cable for each receiver.
If you use the 6000 receiver for OTA HDTV, you can diplex an antenna into the cable from the dish.
A quad LNB is not necessary if you only have 2 receivers. Or if you are using a large switch to combine two dishes.
A basic setup:
[Link: dishnetwork.com]This message was edited by Spiky on 07/30/02 14:12.47.