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Steve Herschbach

Fisher Gold Bug Versus Gold Bug Pro And Teknetics G2

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Fisher Research originally released the 19 kHz Gold Bug model about 1987. It was a real breakthrough design at the time with a compact control box, S-rod, and elliptical coils. The detector is a good unit but is strictly all metal (no discrimination). It has no LCD readout and looks much like the current Gold Bug 2 but has a white lower rod and a black control panel face. Some people are confusing this old model with the new so be aware of this when looking at used detectors. The 19 kHz coils for the old Gold Bug will not work on newer versions of the Gold Bug below.

Around 2010 a number of new Gold Bug models were released by Fisher. First came the Gold Bug in 2009. Then came the Gold Bug SE (Special Edition) which added manual ground balance at a bargain introductory price. The SE with minor tweaks later became the Gold Bug Pro at a higher price. So now we have two basic versions, the Gold Bug and the Gold Bug Pro. They differ from the old 1987 model by having an LCD readout. The standard version of either detector comes with a 5" round coil. There is a Gold Bug DP (Deep Penetrating) which is nothing more than a Gold Bug Pro with an 11" x 7" DD elliptical coil instead of a 5" round DD coil.

The only difference listed by Fisher between the Gold Bug and the Gold Bug Pro is that the Gold Bug Pro has a manual adjustment option for the ground balance and also offers "higher sensitivity".

Both models use a "Ground Grab" button as a simple ground balance method that is quite effective. The Gold Bug Pro allows you to also manually adjust the ground balance setting up or down. The manual adjustment can be used in conjunction with or separately from the Ground Grab button.

The big question is the "higher sensitivity" claim. There are two possibilities here. First, that the Gold Bug Pro actually allows for higher gain or sensitivity levels. However, I was in marketing too long and have a more jaded thought. Manual ground balance allows for a higher degree of control that if used properly can get you more sensitivity. There is a very distinct possibility the higher sensitivity claim follows directly from the ability to manually ground balance the Gold Bug Pro. This could be tested with both units set side by side with identical ground balance settings and max gain. If the Gold Bug Pro is inherently more sensitive an air test should show it. I have not had the chance to do this my self but if somebody wants to there you go.

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My opinion? I believe the Gold Bug and the Gold Bug Pro if outfitted with the same coil are basically the same detector. The only real difference is the manual ground balance option on the Gold Bug Pro. Do you need it? Not really, and especially when you consider that for $499 vs $649 that is probably all you are getting. The Ground Grab function is remarkably effective and would suit most people just fine.

I personally do like manual ground balance and so for me spending the extra money to get it is a non-issue. I do as a rule tell people that if cost is not an issue get the Gold Bug Pro. It is far more popular and would be easier to resell. But in all honesty I think the Basic Gold Bug is the real bang-for-the-buck unit. There is nothing else close to it at the $499 price point that offers full LCD readout target discrimination while in full power all metal prospect mode.

I should note that First Texas owns both Fisher and Teknetics. The Fisher Gold Bug DP (Gold Bug Pro with 11" coil) is marketed by Teknetics as the G2. The Fisher Gold Bug DP goes for $699 and the Teknetics G2 is $749. The $50 extra gets you a pistol grip rod instead of the Gold Bug S-rod and an arm strap. Nice gray paint scheme also. Really boils down to pistol grip vs S-rod, purely a personal preference thing.

I use the 5" x 10" elliptical myself and consider it to be the best all around coil for the Gold Bug. However, right now you have to get it as an accessory or as part of a two coil package. Fisher would be doing us a service to release the Gold Bug with this coil as standard on the unit.

My Gold Bug 2 is slightly better on the tiniest of gold but the Gold Bug Pro easily outperforms the Gold Bug 2 on larger nuggets at depth. For all around nugget detecting the Gold Bug or Gold Bug Pro (and G2) have a better balance of both small gold and large gold capability than the Gold Bug 2.

Fisher Gold Bug Pro & Teknetics G2 Detailed Comparison

To recap first came the original 1987 era Gold Bug with knobs and switches:

1987 era analog Fisher Gold Bug

Then in 2009 we got the new Gold Bug:

Fisher digital Gold Bug

Followed quickly and briefly by the Gold Bug SE. Note how the plus and minus buttons now have dual functions, both Disc and Ground Balance, compared to the basic Gold Bug above:

Fisher Gold Bug SE

The Gold Bug SE was basically the prototype for the Gold Bug Pro, which got a new faceplate decal and a higher price:

Fisher Gold Bug Pro

And finally, the Gold Bug Pro was also marketed under the Teknetics line as the G2 with a different rod/handle assembly:

Teknetics G2

Gold Bug Pro DP compared to Teknetics G2:


Click on images below for larger versions.....




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So just to get this straight in my mind. The GB Pro and the GB DP are exactly the same except for the included coils?

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Yes, the Gold Bug DP is a Gold Bug Pro, same control box, same faceplate decal. They should have called it the Gold Bug Pro DP.

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Excellent article Steve , cuts through the confusion regarding differences between these detectors .  :)


Thank You

Jack .

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Hi Keith,

According to the manual:

"Ground Grab (GG) - This feature is not available in Discrimination mode. Your best results will be achieved by first performing the GG procedure in All-Metal mode. The ground balance setting achieved using GG will carry over into this mode."

I assumed it did but never put it to the test. So I did just now with my Gold Bug Pro (version 3). I have three rocks; one GBs at 89, one at 63, and one at 43. Bottom line is by balancing these rocks and going to disc mode and testing them, along with GB set at 0 and at 999, I proved ground balance does indeed carry over to disc mode. The 89 rock in particular screeched in disc mode when GB manually set very low. However, the rocks would almost never give a target id in disc mode, just audio reports, and not very good ones.

However, the disc mode is very forgiving and it really took huge unrealistic GB offsets to see this in action. I can see why you would not think it is doing anything because with normal adjustments there is no obvious effect in air tests. I suspect with in ground tests in very bad ground it would be more obvious.

Something I discovered by accident also. Set GB at 999 and go the full gain disc. I have EMI static simulating a threshold. Now set GB at zero and go to high gain disc. My EMI totally goes away. GB at 50 minimal EMI. In my location at least, the lower the GB setting in all metal, the less EMI in disc mode. Could software be boosting gain in disc mode as the ground balance setting increases? Hmmm.

Just a quickie test but informative. Thanks for asking!

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Glad your answered with  your observations Steve.

I cant never get anyone to talk about it...

What i notice happens on the G2/GB/Omega is when ground balancing if you get real low like in the Salt range or get real high you will notice some differences in disc mode..

But for say 10-90 range it does not seem to effect the disc mode..

but theres a Ground bal pot inside the machine that is facotry set and if you move that one you will see it effect the disc mode inside that 10-90 range...get it to low and it will fasle like crazy on the soil as it should..

I think maybe for proper I.D. to work they use the preset but when the preset wont cover it by the ground bal manual or grab setting it uses that new setting..

I know what you mean about running  the GB to 999 and the threshold comes in..and lower it and it wil go away in disc mode.....

Ive seen this on a few machine's..I think the freq of the machine is adjusted as you move the ground bal....

I know on machine's that have freq Adjust I can ground bal crudely with it like say a classic 3 or a 1236..

So ground bal effects freq somewhat and vice versa in certain designs anyway..

Glad you posted this Steve i have noticed the same thing yet in the middle ranges the machine seems to use a preset...

I wonder if the internal preset is like a starting point for the manual ground bal...

They may work in unison...

Remember the first GB's that came out and I found they would not hit big silver and reported it to Mike Scott..

They had a recall on them...I was told they had to reset the internal pot to accept the big silver...But at the sime time it seemed it was still weak on big silver...they said the technicians at the asembley line had preset the internal pot to the Omega specs not knowing it required a change..

Those were the 2.9 machines...after that a software tweak was done to help on the high conductors and low conductor's it so seems now..

My 4.0 is very strong on high conductors for freq... the 2.9 even after alignment, it was still weak on silver.. but the 4.0 will hear a silver dollar very well at great distance form the coil..


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I think the GB/G2 units are far more sophisticated under the hood than the simple control set implies. We know, for instance, that the detector is constantly tracking ground conditions. I see things in the field nugget detecting that the detector may be using that tracking information to modify some software parameters even though we are told the ground balance is fixed wherever it is set. Hot rocks bang on a first pass and mellow immediately when returned to and it seems like more than just the autotune is involved.

The GBP has reeducated me into the dangers of discrimination. I run in all metal but since the meter still operates in disc mode check the id before digging. Yet in most cases I am digging everything regardless. The number of small non-ferrous items or larger non-ferrous items at depth that read ferrous in bad ground is truly frightening.

Most detectors I am either in all metal mode so just digging everything. Or in disc mode with bare iron reject set, digging all non-ferrous. So I do not see precisely what I am missing in disc mode. The GBP makes it painfully obvious I have walked away from vast numbers of good targets over the years, even using the most minimal iron disc settings possible. The flip side positive lesson is that huge numbers of good items remain for those of use willing to dig it all. Forget depth, accurate ferrous versus non-ferrous discrimination is the magic bullet we need and are still waiting for.

Or maybe not. Maybe it is better people use disc and leave me stuff to find. The perfect detector would clean areas out rapidly so we best be careful what we wish for.

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Thats one thing I like about the newer machine's with tone break option..

I like to hear it all even in disc mode..

and those tone signals can speak volumes if we listen..

I like to hear a faint tight low tone...I know theres a chance its a good target at depth reading iron...that otherwise would go unoticed in a disc mode..

but yes being a relic hunter first and formost Steve I can attest to all the good targets that are called iron..


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