This message is for anyone who is "in the Philadelphia area" and who has no source of television except over-the-air.
I finally succeeded tonight in pulling in WPVI channel 6.1 from Philadelphia I am 26 miles northeast of the transmitters, which I read online are in Roxborough area.
I bought two RCA powered amplified digital tv antennae from Best Buy and a Sharp Roku TV digital tv (my first digital tv). In everything that follows, I have extended the 2 "rabbit ears" of the antenna fully, about 3 feet long.
If I put the RCA antenna on top of my cradenza in my livingroom, about 3 feet above the floor, next to the Sharp TV, and if I sort of face the black surface southwest of me, I pick up NBC (WCAU 10) but not ABC (WPVI 6).
If I put the same antenna on top of a 3-foot-tall black speaker, on top of the cradenza, adding an additional 3 feet I pick up ABC (WPVI 6) but not NBC (WCAU 10).
The RCA antenna in my bedroom windowsill is connected to Hauppauge digital tv tuner which is connected to my Lenovo computer. I view tv on my computer through the WinTV software that came with the Hauppauge unit. Since I have nothing tall to put the antenna on in my bedroom to make it higher, I pick up NBC but not ABC on my computer.
As I learned on some tech-section of reddit, WPVI in Philadelphia is NOTORIOUSLY difficult to pick up over the air, because WPVI ABC stuck with the older low-frequency system. Most stations converted to or use a higher frequency.
Anyway, I get thrilled when any new piece of expensive tech works. I watch extremely little tv. My satisfaction is mainly knowing I can perform the simplest tasks by myself (I have severe rheumatoid arthritis, including in my hands, making even turning a screw a major challenge).
Just wanted to share the news that, finally, I proved one CAN pull in WPVI ABC from Philly by putting the indoor antenna about 6 feet above the floor.