New to f75..coil pinpointing question

[brassos]

Hello all,
Picked up an F75 today and went out with it and my DFX. My question is simple, where is the "center" of the F75 coil?
I could pinpoint with the DFX, with a round coil, but couldn't quite match the same location with the Fisher. I swept as normal and used pinpoint mode as described in the manual.
Probably a simple answer to a dumb question. And i know it will hit me after a day or so of sweeping.
Thanks in advance.

 

[brassos]

did a google on DD coils and looked real close at the coil itself. There is a small circle on the center vertical axis just above the arm attachment. I higlighted it with a bright paint pen so i see it better. Will test again to see if it is actually the "center".
also found this article:
http://geotech.thunting.com/pages/metdet/info/coils.pdf

 

[AndyNM]

The sensitive area under a DD coil is blade shaped, so by making an X pattern over the target, it is possible to pinpoint a target using the DD to a fairly tight area. Don't forget that the target can be shrinked by pulling the trigger right over the target. That is called detuning.

Andy,NM

 

[Tagamet]

there is a small circle right where the second pair of fins meet the center spine. That seems to be the sweet spot when pinpointing on my F75.
Hope this helps,
Tagamet

 

[rebelbrass]

brassos

One little trick I have found to pinpoint with the DD coil is to watch the spot on the ground where you receive the signal as the center line of the coil passes over the target as you swing. Keep a mental position of this spot, then move the coil forward or backward as you swing over the target location. When the front or rear of the center section of the coil clears the target, you will loose the audio sound of the target. As you move front or rear edge of the coil back over the mental location of the target the target audio responce will return. You can pinpoint very accurately this way without having to activate the VCO pinpoint unless you want to get a accurate depth reading on the visual readout. Hope this is helpful, and not confusing. It works great when you get used to it! Dave HH