VoyForums
[ Show ]
Support VoyForums
[ Shrink ]
VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

[ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 1, 2, 3, 4, 5, 6, [7], 8, 9 ]

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: 12:12:22 04/01/02 Mon
Author: Steve Herschbach
Subject: Re: Specks......
In reply to: Ralph 's message, "Specks......" on 11:23:56 04/01/02 Mon

One thing about the small coils is that it is not just about tiny bits. Small coils can actually get better depth on larger pieces under some conditions.

The chart below (could not get rid of the big gap, so scroll down the page) was put out by Fisher, and is no doubt based on air tests. But it illustrates the point. On nuggets 5 grains and less the small coil get better depth than the larger coils. I also believe that because the small coils "see" less ground, the figures will probably hold up better for the small coils than the large coils, tilting the percentage gain even further in favor of the small coil.

My own tests on a 1 grain nugget in black sand infested soil showed the Gold Bug 2 hit the nugget at 1" with the 10" and 1.5" with the 6.5" coil.

So it is not just about picking up smaller gold, it is also about finding up to 5 grain nuggets at better depths.


Coil Size vs. Depth - Fisher Gold Bug 2






































Nugget Size 6.5" Coil
10" Coil 14" Coil
.5 grain 1.5" .25" on coil
.8 grain 2" 1" .5"
5 grains 4.5" 4" 3.5"
1 pennyweight 5" 6" 6.5"
1 ounce 8" 11" 14"



Finally, do not forget the nook and cranny factor. I have found some nice nuggets down in some little holes that the larger coil should have detected better than the small coil, but passing the big coil over the top of the hole put the coil too far away. Getting the little coil down into the hole several inches closer to the gold can make a difference even on larger nuggets.

Steve Herschbach

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Replies:

[ Contact Forum Admin ]

Forum timezone: GMT-6
VF Version: 3.00b, ConfDB:
Before posting please read our privacy policy.
VoyForums(tm) is a Free Service from Voyager Info-Systems.
Copyright © 1998-2019 Voyager Info-Systems. All Rights Reserved.