Isaac seemed convinced that the drones became visible in 2007 as a result of experimentation with a device that manipulates some type of field which interferes with the drone technology. This makes sense and also raises a few more questions. If such a device were activated, it appears that it's effects are localized since all of the drone photographs are within the same geographical vicinity. All but the Lake Tahoe photos are within 20 miles of the San Jose/Sunnyvale area, Lake Tahoe being approximately 100 miles from that area. It appears a facility (PACL?) was/is operating near the epicenter of those photos where the device was being used.
Possibly the device is adjustable in power. If the device was activated in the Sunnyvale area on a low power setting in could be responsible for the sightings close by. Perhaps a higher power setting allowed it to disrupt drone activity as far away as Lake Tahoe. If that is the case, then we could expect potentially more sightings at the time the Lake Tahoe photo was made. (Do we know the date of those photos?) Another possibility is that there is a different facility closer to Lake Tahoe, and of course near Montgomery Alabama. Who knows, the effects of such a device could reach across the country or even around the world. Or, perhaps the device was traveling. Maybe it was on tour for some reason and activated periodically to locate rouge drones. Perhaps another drone type craft was traveling at the time equipped with this interrupting field capability.
So how many drones are there right above our heads that remain hidden from view? Are there more in certain areas, or are they more evenly distributed? Some evidence suggests that they are more prevalent around forested areas.
If the photos are real, and a facility nearby was responsible for making the drones briefly visible, and this whole matter is some sort of controlled disclosure, it could be that the locations of the Chad and Rajman reports were deliberately misidentified to throw off attempts at locating the facility based on a radius of effect from such a device. Since we now know absolutely where most of these photos were made, it could be possible to find an epicenter for this field effect and get close to locating the actual facility.
The device responsible for this field effect is likely the device referred to in the Q4-86 Research Report as S1. In that report, all of the blacked out material seems to be related to S1. Since this report appears to focus on 4 artifacts. The first 3 are A1, A2, and A3, those shown in the photos. The 4th being S1. My assumption is that A stands for artifact, and S must be the first letter of some categorical identification for the S1 device. So what does S stand for?