Transmitter Accessories

Follow Avatar Anthony Caplin
Updated : Created :
In this article

Transmitter clamps

The transmitter clamp fits around a pipe or cable and safely applies a signal to a live insulated cable without interrupting or disconnecting the supply. The clamp applies a very discriminating signal to a target line with reduced coupling to other lines. A clamp can sometimes be a more effective method of applying the signal than Direct Connection.

The target line will carry the strongest signal. The other lines will carry the weaker return signal. If the system comprises only two conductors, they may carry equal signals.

warning icon.pngWARNING! Do not clamp around uninsulated live conductors

warning icon.png WARNING! Before applying or removing the clamp around a power cable, ensure that the clamp is connected to the transmitter at all times.

The clamp may buzz or vibrate if it is placed around a power cable that has significant net current flow. This is normal and does not harm the equipment.


Connecting the clamp

transmitter output socket.png

Transmitter output socket

Connecting transmitter clamps

  1. Plug the clamp into the transmitter output socket.
  2. Put the clamp around the pipe or cable and ensure that the jaws are closed. Switch the transmitter on.

Clamp connected icon

The line should be grounded (earthed) on each side of the clamp for the signal to transfer to the line. Ground the line if necessary. An insulated cable may be traced even if it has no actual ground connection, providing a reasonable length is buried either side of the clamp to provide capacitive coupling to ground (earth).

NOTE: It is not necessary to make a ground connection from the transmitter when using the clamp.


Transmitter clamp range

Although transmitter and locator clamps look the same, they have different internal windings. To prevent the wrong clamp being connected, transmitters and locator clamps have plugs of a different orientation.

Standard signal clamps

The standard clamps apply the transmitter signal very selectively and effectively to a target cable up to 130mm (5¼”) in diameter using frequencies from 8kHz to 200kHz.

The standard and small clamps have a double spring action for positive toroidal contact.

Small signal clamp

The small signal clamp is useful for applying signals from 8kHz to 200kHz to a target cable in a pedestal or other place with limited space. The clamp is suitable for cables up to 50mm diameter.

Current Direction (CD) clamp


cd clamp.png

CD clamp

The CD clamp plugged into the accessory socket of the transmitter enables CD signals to be applied to individual cables.

warning icon.pngWARNING! The transmitter must only be connected to live services using the appropriate accessory such as a plug connector or live cable connector.


Transmitter external power supply

The external Mains or vehicle power supplies provides an alternative and convenient method of powering the transmitter.

warning icon.pngWARNING! The mains power supply rating are: 100-240VAC, 1.3A. Always use an adequately rated detachable mains lead.

warning icon.png WARNING! The mains power supply is not IP rated and should not be used in wet locations


transmitter dc input.png

Transmitter DC Input

To use the mains or vehicle power supply units connect them to the DC input socket in the transmitter before connecting them to the mains or vehicle supply socket.

warning icon.pngWARNING! The mains PSU supply cable is the disconnecting method for isolating the unit from the main supply.

warning icon.png WARNING! The battery compartment lid is the disconnecting method for isolating the unit from the battery supply.

warning icon.pngWARNING! Do not position the equipment so it is difficult to disconnect the unit from each supply.

warning icon.png WARNING! Protection will be impaired if used in a manner not specified.