Thanks Mike for the detailed reply!
I am currently using the remote antenna in my attic with the C1M1LTEA in order to get a better signal strength. I consistently have 3 bars per the device 7 segment LED. I checked the manual and it looks like the cord is only 18 inches long and it recommends mounting it 5.5 to 7.5 inches away from the primary antenna.
Can I still use a secondary antenna? Do you think this would help?