First, as a 'New Member' I / We don't know much about you so, how long have you been metal detecting? What type of hunting / sites do you plan to search the most? What are you mainly looking for? Have you had or used any detectors other than the BH Discovery 3300 or Tracker IV, and if so, what were they?
jpbundy: said:
on a air test the discovery 3300 will do 11 inches on a quarter
however, an air test with a aluminum screw cap will get 12 inches.
problem is with the screw cap i get the low tone only at 5 inches
and less.
And what did the Quarter do at the closer distance? Did it also drop in tone?
Were you holding the Screw Cap in the same orientation to the coil, as if laying flat-to-the-coil, on each test sweep? Were you moving the Screw Cap completely across the coil's width as if being encountered afield, or making a little wiggle type wave of the Screw Cap?
An aluminum Screw Cap is a high-conductive target that should produce a higher-conductive audio response. I would expect it to produce a High-Tone audio, or Mid-Tone, depending on the particular make and model detector and the available audio Tone ID pitches.
jpbundy: said:
if i could get the low tone the whole 12 inches would be really great.
No, it would be really bad because if it is an aluminum Screw Cap, it should be producing an audio Tone based on it's size and conductivity which, most typically, shouldn't be a Low-Tone.
jpbundy: said:
from 5 inches up to 12 inches i get a high tone ,which is bad.
At a distance from the coil to it's maximum detection range it should produce a 'proper' Tone ID based upon it's conductivity, and that means other higher-conductivity targets should also produce a 'proper' Tone ID based upon their conductivity, be it a lower-conductive US 5¢ or higher-conductive 1¢, 10¢, 25¢, etc.
jpbundy: said:
my question is why cant there be a low tone the whole 12 inches?
Because there shouldn't be a Low-Tone for a higher-conductive target at any normal coil-to-target detection distance.
jpbundy: said:
thanks for the reply, i just turned the sensitivity down to 3 bars out of 6
that way it only detects down to 5 inches
Bad move, in my opinion as well as others have started. No, we do not like some of the annoying trash out there, but we have to contend with it. All of the higher-conductive targets, to include Screw Caps, ought to be pinpointed and recovered before we continue on. They have a Target ID read-out in the range of desired targets, and removing them also lets us re-scan the spot to see if they were masking a desirable keeper.
If all was tested correctly, and if the Screw Cap is in fact an all-aluminum object, then you should get a good higher-tone response and it should be recovered. If not, you're going to be missing a lot of very desired targets. If it is such an object and you are not getting a 'proper' higher-tone audio at a closer or shallower depth, there is a glitch with the coil or a definite glitch with the detector that needs to be addressed.
Monte