[GroundUrMast]

The least expensive option and the option that 'jumps off the page' is to buy an Ideal brand #85-133 3-way splitter. (About $5 at Home Depot). Remove the amplified splitter, without power it is an unpredictable attenuator... it's not intend to work without power and it's not intended for wet locations. (Use the splitter port labeled with the lowest loss to drive the longest cable run or weakest tuner.)

Unless you are blocked by dense trees, the CM4220 should do well except for real channels 2 through 13. Another option would be an Antennas Direct CS5, which is intended as a high-VHF antenna, but also does well as a UHF antenna in strong signal conditions as yours. The UHF pattern of the CS5 tends to be somewhat omnidirectional.

Alternately, consider adding an Antennacraft Y5713 with your existing antenna. You can combine the UHF and VHF signals with little loss using a UVSJ (UHF/VHF Signal Joiner) The Antennacraft antenna and UVSJ may be stocked at Radio Shack or you can certainly find them online. The WGTV and WPBA signals should be 'rock solid'. This option may not make the signal from WPXA as solid as the CS5 option but you may be able to experiment with removing the reflector screen from the CM4220 to allow it to receive more signal from the rear.

(You have a lot of strong signals, including FM stations that don't appear on your TVFR. This argues against using an amplifier unless you are going to be feeding a large number of antenna outlets, in which case you would need to use a high-input amplifier spec'd for the application. An overloaded amplifier will leave you with some or all channels less reliable depending on the severity of the overload condition.)