Gas Tube Protectors

These devices feature a gas filled arrester that is connected between the two conductors of the coaxial cable. During normal operation the gas arrester is open-circuit and so it does not affect signal transmission. In the case of a surge, the gas arrester fires and becomes a virtual shortcircuit with a small residual voltage. This means that the bulk of the surge is diverted to ground without it reaching and damaging connected equipment.

¼ Wavelength Stub Protectors

The concepts involved with the operation of these devices are direct from standard transmission line theory. A short-circuited stub is connected in parallel with the signal path. Different signals “see” different impedances from the stub depending upon their wavelength relative to the length of the stub.

¼ wavelength stub protectors are accurately manufactured such that their length is exactly one quarter of the wavelength of the intended operating signal. Because of this, the stub appears to be open-circuit to the operating signal and short-circuit to surges. This allows the intended signal to pass straight through the protector, whilst surges are diverted to ground. These devices contain no electronic components whatsoever.