|TERK AM Advantage Magnetic Loop|
|Modified with a Ferrite Loopstick Pickup|
|This is one of my TERK loop AM antennas. There is nothing magic about the TERK, except that it is well made, has a very smooth tuning capacitor, is of a convenient size for tabletop use, and is cosmetically suitable enough to leave out on the desk or table.
The two photos above show the loopstick in various positions. It can be raised or lowered vertically, inserted or withdrawn from the loop's opening, and skewed left or right.
Below is a closeup of the double joint, which allows the various positions of articulation. A compound joint would also allow for rotational positioning.
Note that the actual ferrite stick and coils are encased in a plastic housing -- good idea for the sake of protection and appearance. This one has been liberated from the back of an old stereo receiver
|The range of positioning adjustments allows for the TERK to be oriented for best signal capture and least noise. Then, the loopstick can be adjusted for maximum signal transfer or lowest local noise pickup. This becomes a passive means of "noise bucking" or "phase cancellation."
The pickup coil is fed to the low impedance input of my receivers. If you want to add another variable to the tuning process, you can feed the TERK's input jack from an end-fed antenna and good earth ground. Then, the TERK can be used to buck noise that the outdoor antenna is receiving (not terribly effective, since there are no level adjustments to balance the system, but it does sometimes work). But the big bonus is that the TERK becomes a preselector, of sorts. Try it. Play with all the permutations. Try bucking out a local AM station that bleeds over into the next channel. Try using it as a preselector. Etc, etc.
I'll add to this page as things develop.