add a third dvr

Need to know what equipment you currently have ....

• DVR models?
• Receiver models?
• Type of dish (does it have one or four coax cables connected to it?)

Easiest course is to call DirecTV.  They'll send someone to hook it up for you for ~$50, including the price of any new or additional equipment needed. 

I have

1-hr20-100,1-hr22-100 and haven"t gotten the third one yet.

My dish has 4 coax comming out of it

two of them go to each of the dvr

Thanks.  Then you'll need to add a Zinwell WB68 multiswitch to expand the dish's four outputs to eight.  All four dish outputs will connect to the Zinwell's four SAT IN connectors.  The existing two DVRs will use four of the Zinwell's OUT connectors.  Two new RG6 coax cables will run from the Zinwell to your new DVR.  And that new DVR will need B-Band Converter (BBC) modules, unless it's an HR23 model.  

Again, DirecTV can take care of all of this for you for ~$50, less than it would cost to buy all that stuff yourself. 

That is what I needed thanks for your help.