I just got DirecTV installed and I am using the existing wiring from the DishNetwork install to mirror my new receiver. I keep getting "searching for satellite 771". After some research I found that some diplexers caused this problem. So I removed the diplexer and sure enough all my HD channels came through. Now the issue is that I had the previous receiver mirrored to the TV in the kitchen and now I can't with my current DTV setup. I called tech support to ask for a recommendation for a diplexer. They stated that it is not recommended at all. Also that it has nothing to do with bandwidth for the HD channels. The guy stated that the signal is not strong enough and that I may want to put a multi-switch that is amplified in the place of the diplexer. This does not make sense to me. I had the setup pictured below working for over 2 years on Dishnetwork. How would the signal strength traveling through the RG6 be any different from one receiver to the next? Is there something I am missing?

If anyone can give me better insight as to why this doesn't work or has any experience in ways that it can work I would really appreciate it.

http://www.fileden.com/files/4148/DirecTV%20Diagram%20copy.jpg

It's not the strength of the signal - it's how the frequencies work between the services. You have to run lines directly to the devices with D* and can only split them with a multiswitch. Diplexers don't work properly with the type of system D* uses.

Thanks for the clarification. So do I need to run 2 separate coax cables or will the multi-switch replace the diplexer and combine the signal back into one cable? Also if I run 2 separate lines will I still need a multi-switch or just run line out of the RF modulator into the other TV?

Thanks for the clarification. So do I need to run 2 separate coax cables or will the multi-switch replace the diplexer and combine the signal back into one cable? Also if I run 2 separate lines will I still need a multi-switch or just run line out of the RF modulator into the other TV?
The multiswitch only lessens the number of cables that have to run into your house. You'll still need one direct line from the multiswitch or dish to each box. I believe you still need at least 2 lines running into the multiswitch in order to split the signal with it.

DirecTV does not yet have single line service.

The multiswitch only lessens the number of cables that have to run into your house. You'll still need one direct line from the multiswitch or dish to each box. I believe you still need at least 2 lines running into the multiswitch in order to split the signal with it.

DirecTV does not yet have single line service.

I already have a multi-switch in the garage with a line running to each receiver. There is no receiver in the kitchen and I am using a single receiver running HDMI out to the main TV and the rca out through an RF modulator to send directly to the second tv in the kitchen. So I am only using the multi-switch from the dish to the original receivers. After the receivers I have not touched the multi-switch. DTV recommenced getting a second switch. So would this replace the diplexer or could a diplexer or switch be avoided with a second wire run?

I already have a multi-switch in the garage with a line running to each receiver. There is no receiver in the kitchen and I am using a single receiver running HDMI out to the main TV and the rca out through an RF modulator to send directly to the second tv in the kitchen. So I am only using the multi-switch from the dish to the original receivers. After the receivers I have not touched the multi-switch. DTV recommenced getting a second switch. So would this replace the diplexer or could a diplexer or switch be avoided with a second wire run?
It sounds like the box isn't send both the HDMI and composite signals at the same time. I'd try it on one of the other boxes to see if it's just the box.

It will mirror the receiver to the kitchen when I have it set up like this, I just don't get all my HD channels.

Get rid of the diplexors. You don't need them. Just run the line straight to the receiver, run HDMI to the main TV then use the RCA out to the RF converter and run that to the other TV. You've made it harder than it has to be.