Greetings JNEW,
I understand your disappointment in minimal improvement in reception. If I were installing your setup, the HBU22 might be a little too weak for my tastes, especially going after the single digit db strength NYC stations.
Your plot has many 2 edge signals. This makes reception trickier and requires a strong antenna to offset the quirky things 2 edge signals can do. Two-edge signals are terrain blocked from your location. This means you have no line of sight and signals have to bend to get to you. This causes unpredictability as they bounce around. As such, antennas with wide surface areas and good amounts of gain such as a DB8, DB8e, U8000 and CM4228 are often good choices in these situations.
The trade off is these larger UHF aerials are more directional. That will make you have to point specifically at Philadelphia or NYC. It sounds like you are wanting NYC so orientating to magnetic 21 will be where you'd want to go.
Remember, TV signals are in 3 bands: low-VHF (channels 2-6), high-VHF (channels 7-13 and UHF (channels 14 and above).
For NYC, you'll need high-VHF and UHF support.
If I were spending freely to give myself the best chance at reception, I'd purchase a two antenna set up starting with a
Antennas Direct DB8e for UHF reception.
http://www.solidsignal.com/pview.asp?p=db8e. The DB8e is attractive in this situation due to the ability to adjust each side of the antenna should you have signals bouncing off path from the TVfool heading. Generally though, with this design it's gain is strongest in the given direction when you keep both panels facing the same heading. Further, I'd suggest a
Antennacraft Y10-7-13 for high-VHF.
http://www.solidsignal.com/search.asp?q=Y10-7-13. This will give you the strongest high-vhf only beam on the market to focus on WPIX, WABC and WNET.
Mount both antennas on tripod on your roof. Use 10' pole. Mount DB8e on top of pole and Y10-7-13 4' below. Tripod supplies are here:
http://www.solidsignal.com/search.asp?q=tripods. Recommend heading of magnetic 21 on Both antennas.
Connect DB8e coax jumper to UHF input on already owned RCA TVPRAMPR1 preamp. Connect Y10-7-13 coax to VHF preamp input. Run single coax drop into home. Make sure to have coax switch on preamp on "separate." (its under the funny rubber plug by the inputs)
After you do all that, connect one TV to the coax coming into the home. Perform scan after aiming. See what you get. You ought to be able to see the majority of the NYC signals down to WNBC and WXPN. After that you are getting into the signals that are so weak atmospheric variances can knock them below reception threshold.
RE: Coax run. Can you estimate how long each of your splits from splitter to TVs are in total? How long is your drop coming down off the antenna?
It's a lot of work no doubt. You are in a somewhat challenging situation. It calls for a robust set up with higher gain equipment to help you offset those fickle 2-edge conditions.
I hate to blow up your HBU22, but I've done exactly that.
In my amateur opinion, go big and go strong especially for NYC. I've given you a set up that should get you well on your way.
Let us know how it pans out.
Regards.
