Thank you to everyone who responded.
Yes, using a Yagi antenna helped, but in case anyone else is interested in monitoring this huge complex
which provides for some interesting listening, here is the another part of the solution...
After you program your SDS200 or SDS100 with the system from the RR database, ( and you cannot do it
through Sentinal, I used ProScan), you MUST go into the radio and run the LCN finder function. Be prepared to leave the scanner running this mode, maybe for a day or more. After the scanner finds ALL of the LCN channels codes, in my case it was 9 out of 12 for American Dream system, hit FUNCTION, then SYSTEM the the "E" for yes so you can SAVE the LCN channel data. Your radio will then monitor the system.
I found this info here on RR in another section dealing with DMR issues.
Enjoy!