fluxgate magnetometers

Since I'm still the loose gun that's looking into the HAARP thing from a debunking angle, I decided to look into the infamous magnetometers that are being quoted to show HAARP activity.

Magnetometer Manual

Ok, there's a lot of techno-stuff in there, but what I want to come to is page 3. The specifications! It says here, the thing has a frequency response between DC and 25 Hz. So any variations in the magnetic field that go faster then 25 Hz are likely not to give an accurate reading. Even less so probably they are going to pick up the megahertz regime radiation emitted by HAARP:

Antenna Design and frequency range

Note that radiation in principle can be thought of as travelling waves of mutually orthogonal electric and magnetic field, so yeah, when the fluxgate magnetometer would have a response even in the megahertz regime, sure, you would be able to see HAARP activity. But with this severe mismatch in frequencies I would put out a good bet that you can't see it.

Other point: There are many other devices that emit in the near microwave regime, like cell-phones. Why wouldn't they show up if HAARP can show up with the indicated frequency mismatch???