That one is out of stock at ScannerMaster. However, it is in stock at
Universal Radio and
Amazon. The Amazon seller is Police Scanner Outlet, which is the name
Bearcat Warehouse uses on Amazon.
Actually, you would need to use the SMA to BNC adapter with either of these antenbnas. Your HP-2 has an SMA connecror to the antenna, whereas both of these antennas need a BNC connector. To use the second antenna on your HP-2, you'd have to use the SMA to BNC adapter that came with the scanner, plus a 90 degree elbow (BNC on both ends) so that you could position the antenna vertically. However, there s combination
adapter that has an SMA male to connect to your HP-2, and the other end of the elbow has the BNC female adapter to connect to the antenna.
Since the HP-2 does not hear the system in your house, but does work in your vehicle, then something in the house may be affecting the signal strength. If your house has aluminum siding, and/or foil backed insulation in the walls, either of those would reduce the signal you can hear inside the house.