About CD reset
When you trace a signal on very long target lines, the transmitter signal gradually bleeds into the ground by capacitance. This means the phase angle of the remaining signal gradually changes. A CD Reset can be used to re-establish correct CD operation.
To perform a CD reset, press and hold the
key.
This is referred to as phase-shift and can occur whenever an alternating current signal is flowing in a system of conductors that have a significant capacitance or inductance. The relative phase angle between the two frequencies will alter, but only over extended distances.

CD reset
The illustration above 'CD Reset' represents a buried line with significant capacitance to ground. It illustrates the gradual phase-shift that occurs along the line. The diagram shows a reference point on each waveform. At first, the reference point occurs right on the Peak of a positive half cycle (A). It gradually moves towards the zero crossing point (D) and ends up on the Peak of a negative half cycle (F). The direction has shifted from forwards to backwards. At the intermediate point (D) the current flow cannot be determined. At this point the CD arrows on the RD8200 locator will flash on and off. In the example shown in the illustration, by returning to (C) which is the last point at which a CD reading was achieved, and performing a CD reset, the response at (C) will be equivalent to that of (A).
In most cases the phase angle shift does not occur until many kilometers from the transmitter and in some cases a CD reset may only be required every 20 kilometers (15 miles).
Performing a CD reset
You should perform a CD reset every time you select a CD frequency. CD reset can only be performed when in CD mode.
To perform a CD reset:
While using any CD frequency,
- Press and hold the
key.
Alternatively
- Press the
key to enter the menu.
- Scroll to the CDR menu using the
or
keys.
- Press the
key to enter the CDR menu.
- Select YES.
- Press the
key to reset CD and exit to the main menu.