Ferric rod coil used for pinpointing

[cs6gold]

I have just finished building GS4 and it works great. I got the machine to detect 1.5 grain nugget at about 1/2". On the GS4 and GS5 there is a ferric rod core coil for pin pointing. One switches from main coil to pin pointing coil. On my GS4 I am using a 300uH coil. I like to have the same arrangment with my detector. In years past on this forum Eric and others talked about the PP and what ferric rod coil that would work. I just don't know enough about ferric rods / coils combinations. Does anyone out there know what ferric rod would work with my arrangment? or point me in the right direction to figure out what would?


Rick S

 

[bbsailor]

Use only a soft ferrite like (ICH)ROD7.5/50 in the following web link. http://www.surplussales.com/Inductors/FerRods/FerRods.html

Order a few of these rods to experiment with different numbers of ferrite rods in various configurations such as:
1. Single 2" rod (try this first)
2. Two rods glued end to end to make a 4" long rod
3. Three rods in a triangular bundle
4. Seven rods with one in the center and six more around it to make a fat rod bundle

To minimize noise ground the ferrite rod. You will need to ensure that the damping resistor is optimized for the probe that you are making.

I hope this helps.

bbsailor