Triplett Fox & Hound 3 – PN: 3397 - Manual (Page 40)

40
Reposition the test wires so that they are inline with each
other, with a small gap between them (1/16" to 1/8"). See
Figure 8. Again, trace along the length of the wire and note
how a null point occurs at the gap. This technique can be
used to find the open fairly precisely, if the spacing of the
wires and the location of the open lends its to this approach.
TRIPLETT
TONE HI
LO
CONTINUITY
TALK
WARBLE
OFF / LINE POLARITY
STRONG
SIGNAL
OPEN
NULL
Figure 8