How committed are you to getting NBC (RCH4,VCH4)?
As GroundUrMast explained, RCH4 is on the low-VHF band at around 69MHz. The lower the frequency the longer the antenna elements need to be. The DB8e is a UHF antenna so its not going to work to pickup RCH4. The rabbit ear antenna may not even extend long enough to get sufficient gain for RCH4. If it has an UHF loop built in as well that tends to make its performance on VHF worse.
My recommendation is to run a test to see if you are wasting your time trying to get RCH4. If you have an extra piece of coax with F-connectors on each end that you can sacrifice, I would build a half-wave dipole antenna following the diagram at the bottom of this page;
http://www.northcountryradio.com/Articles/fmdip.htm You don't need a balun for this test.
According to the math you need a T-length across the top of 6.8 feet. That is 3ft 5" per leg! Clip the connector off one end of the coax cable and get some lamp cord (solid wire might be better but will be harder to work with) from a dead appliance and cut a 3ft 5" length and then split into two wires. Attach it as shown in the diagram. Ideally the connection should be soldered but if can't do that just twist the connections and secure with e-tape. Mount the top of the T along the ceiling of a southern facing wall as high as you can go and still reach the TV input on the other end of the cable. Keep it about 8-10 inches from the top of the ceiling. Re-zero your TV tuner (very important) then plug in this test antenna and rescan. If it comes in okay with this custom tuned antenna then there is hope.