Also the Freq of the 1270 is 8.2 and the 1266 is 4.8, and I think the 1265 was also 4.8, and the 1260 was different, don't remember what the 1260 was, but was told the the 1260 coils would not work on the 1265 & 1266, and the coils on the 1266 & 1265 would interchange.
I hunt with a father that uses the 1260 and his son uses the 1265 and have made many good finds over the years.
Below is a copy and paste from the 1270 manual, many like the 1266 better than the 1270...
NORMAL DISC MODE
When rejection of a full range of other non-ferrous trash is desired,
the NORMAL DISC mode will be necessary. Make sure the ALL METAL
GROUND ADJUST is OFF; that is, fully counterclockwise until it “clicks” into
the “0” position. The IRON toggle switch must also be OFF. Adjust the
NORMAL DISC knob to reject the unwanted “trash” targets (see figure 2).
When the NORMAL DISC is set at “0”, all metals will be detected. As you
turn the NORMAL DISC knob clockwise, certain metals will be rejected.
At the full setting of “10”, most iron, foil, and aluminum will be rejected,
while copper and silver will still yield a good signal. Adjust your sensitiv-
ity clockwise to the desired level (preferably until a slight threshold tone
is heard, at about “8” or greater). Reduce the sensitivity slightly if you
prefer silent search. In high trash areas, turning the SILENCER toggle ON
will reduce, and in most cases, eliminate the “clicks and pops” that result
from some rejected targets. Remember that the NORMAL DISC mode is
a MOTION mode. Slight movement of the coil is required to detect an
object. When NORMAL DISC is the primary operating mode, pushing
the MODE TRIGGER forward switches the 1270 into the IRON DISC mode.
IRON DISC MODE (SEE PRIMARY & SECONDARY OPERATING MODES PG 7).
IRON DISC MODE
Searching in IRON DISC may be preferred when small iron objects are
to be rejected. In fact, this mode greatly improves the detectors abil-
ity to “see through” iron trash to the good non-ferrous targets often
sought after. Make sure the ALL METAL GROUND ADJUST is OFF; that is,
fully counterclockwise until it “clicks” into the “0” position. Flip the IRON
toggle switch up into the ON position. Adjust your sensitivity clockwise
to the desired level (preferably until a slight threshold tone is heard, at
about “8” or greater). Reduce the sensitivity slightly if you prefer silent
search. In the IRON DISC mode, you have two features that enhance
the performance of the 1270: the SILENCER and the IRON DISC adjust
knob. The IRON DISC knob gives you the ability to “fine tune” the amount
of iron you wish to reject. Turning the IRON DISC knob clockwise causes
larger pieces of iron to be rejected. You may hear some normal “clicks
and pops” when the coil passes over these targets. In high trash areas,
turning the SILENCER toggle ON will reduce, and in most cases, eliminate
the “clicks and pops”. Remember that the IRON DISC mode is a MOTION
mode. Slight movement of the coil is required to detect an object. When
IRON DISC is the primary operating mode, pushing the MODE TRIGGER
forward switches the 1270 into the NORMAL DISC mode. (SEE PRIMARY
& SECONDARY OPERATING MODES PG. 7)
