Spule oder Drossel

摘要

The coil has a low Q factor at low frequencies and a high one at high frequencies. It is intended for an amplifier circuit using semiconductor components or electron tubes. The individual coil turns consist of a ferromagnetic wire which is coated with a thin metal film of high conductivity. Preferably a hollow conductor is used for the turns, such as silver, the tubular conductor having very thin walls. The coil former may be of ferromagnetic material and also coated with a film of high conductivity. When used in a series connection with a second coil, a cancelling circuit effective at high frequencies may be incorporated. Alternatively the second coil may have itself the same effect.