Ferrite antenna: Is the signal pulled in like a magnet?

[Mike(Mont)]

Just a note most people probably already know--keep you hands away from the ferrite rod.

[Mike(Mont)]

I tried to rewire the loop antenna. It was better before I messed with it. Now it gives a wide response instead of a sharp, narrow one. So back to the drawing board. But I am leaning more towards the fat, short ferrite rod again. The loop is just too sensitive and touchy, and somewhat delicate (if the windings get moved out of place).

[Mike(Mont)]

When I get my hand near the unshielded ferrite rod, it starts to squawk and squeal, hiss, crackled, spit and sputter, and a few others. I tried insulating it but that had no effect. From eight inches (20cm) I don't hear any of this and it seems to work fine. Haven't tried to shield this one, but I suspect it might help some as the shielded loop does not exhibit the interference nearly as much. I just wonder with the pistol detectors how much this is a problem because the hand is near to the ferrite rod.

[Mike(Mont)]

That thin ferrite rod is disgustingly fragile. I can't see using that on a pistol detector--just tap the case with your finger and you risk breaking it.

[Mike(Mont)]

What difference does a longer ferrite rod make? Does it change inductance?

[Geo]

No.
If you use it at input of a tuned circuit of a receiver then has the ability to catch smaller signals or to become more directional.

[Mike(Mont)]

Okay, thanks Geo. Looking at those plastic coated rods at Stormwise.com