Well, don't give up just yet. It may seem to be a losing battle, but when you get it all figured out and the sensors to working, things will change. It took me a while and some experimenting with the sensors to get it right.
I think if you put out some corn or other bait and have the hogs coming to that, then you can place the sensors close to the bait to help detect them. If the hogs are just meandering here and there, then the sensors may not work as well. Try to get the hogs where you want them and place the sensors accordingly.
I started out with one sensor, but I had critters like skunks and possums hitting the bait and it not notifying me. I didn't want anything to get through, so I began to add additional sensors, one-by-one. Then, I experimented with height above ground level, and finally began setting them low to the ground, around a foot high. But, that's for small critters and coyotes. Hogs may require them to sit a bit higher.
Also, I noticed that a couple of the sensors seemed to detect from the side more, rather than straight on. One seems to pick up movement / heat better when the target is more left of center. So, I turned it slightly to the right so as to have the detection zone more closely aligned where I wanted it.
I have my sensors set pretty close to the bait site, probably 15 feet or so max. One (the one in the photo above) sits even closer. I also have one sensor higher up on the hillside that is generally the first to detect a coyote coming down the hill to the bait. The prevailing wind blows up hill, so the coyotes approach the bait from the uphill / downwind side. That one sensor generally gets them even before they have a chance to get to the bait site where the other two sensors monitor them from different angles.
As to distance with the Driveway Patrol, I can't say for sure how far mine will work since I've only used it at the 60 yard site. However, DoubleUp on the forums has used his at a 145 yard bait site and it works. But, he modified his (and mine) with external antennas on one transmitter and the receiver, thereby adding range. There is an explanation in the Predator Hunting posts, baiting section, where he explains how to do it. It's probably several pages back, but you may need to ask him if you want to try that. The antenna will most likely give you the added range you may need.
My receiver in the cabin has the antenna, but only one of the three sensors has an antenna. The other two sensors are as they come from the box, with the exceptions of some camo paint, and they work just fine at 60 yards.
All my sensors work on the same frequency, 434 MHz. The paperwork that came with yours should list the frequency. I'm curious what yours operates on.
How far do you need the sensors to work?
Here are some other coyotes that were taken with the Driveway Patrol alert waking me during the night.
This is the sensor DoubleUP modified for me, by adding an antenna and placing it in a sterilite box.
Here's the bait site setup I currently have.