F75 and Micro Jewelry Settings Question

[lloyd0161]

I have been comparing my F75 to my new G2 for micro jewelry. Some time spent on the picnic table with my wife's jewelry box has produced some mixed results. I have noticed the following while trying a very small gold stud earring:

1. F75 in Discriminate Mode: Small gold earring not detected unless it is literally touching the coil.
2. F75 in Motion All Metal: Small gold earring comes through loud and clear to about 5 inches from the coil.
3. G2 in Discriminate Mode: Small gold earring comes through loud and clear to about 4 inches from the coil.
4. G2 in All Metal: Small gold earring is detected out to around 6 inches or so from the coil.

I guess the question is; does the F75 need to be in all metal when hunting for small gold jewelry or gold nuggets? If not, is there something wrong with the detector?

 

[lloyd0161]

Problem solved. I did not know this but the very small gold objects register in the iron range on this detector. Hence why the all metal was working and the disc not. My wife's smallest gold earrings register in the 9 through 11 range which is also iron on this detector.

 

[Smudge]

The metal content of the earring stud can also affect the result.

 

[ElginTim]

Have had something of a similar experiences with my F70, the studs come in right easily in the '20s with the small 5" DD coil on it but with the 11" DD coil no dice. But my disc is up at 21. Good to know in the totlot and sand world, insane to chase in the turf world unless you know you're looking for one for someone who lost it.

 

[WV62]

Below is some info on gold testing compared to each coil that I have.

Ron in WV


Detector model F75 Ltd
2= positive response
1= weak or scratchy response
0= no response

Overall Detector score on gold items (12 being max)


F75Ltd Coil Coil Coil
Gold 11"dd------- 5"dd--------- 3.5x6.5----- Ave.
Man's Ring--------------- 2------------- 2------------- 2-------------- 2
Sm. Ear Ring----------- 1-------------- 1------------- 2-------------- 1.33
Small Chain------------- 0------------- 0------------- 1-------------- 0.33
Med. Chain-------------- 0------------- 1------------- 2-------------- 1
Lg. Chain---------------- 2------------- 2------------- 2-------------- 2
XLg. Chain -------------- 2------------- 2------------- 2-------------- 2
Coil total------------- 7------------- 8------------- 11------------ 8.67

 

[therover]

I have not had my F75 LTD long, but I do know there are several different 'modes' ( ie, DE, JE, BP, CL) that it can run in, and I do believe different results may occur when running in those modes.

It would also stand to reason that the Gold Bug DP/Pro and G2 models would be better at small gold jewelry due to their higher frequency.

Lastly...do you have the small 5 inch DD for the F75, and if so, did you try that coil ?

 

[Big Boys Hobbies]

The G2 is more sensitive because of the higher freq it runs.

Yes all metal would be the most sensitive way to run the F75 for small gold.

 

[WV62]

I have not had my F75 LTD long, but I do know there are several different 'modes' ( ie, DE, JE, BP, CL) that it can run in, and I do believe different results may occur when running in those modes.

It would also stand to reason that the Gold Bug DP/Pro and G2 models would be better at small gold jewelry due to their higher frequency.

Lastly...do you have the small 5 inch DD for the F75, and if so, did you try that coil ?

Sorry for that messed up chart, I didn't catch that it was changed after I pasted it. So this time I just took a picture, maybe it will be a little more understandable.

Being I was testing jewelry I done all my test in the JE mode and now that you can see my chart you can see I tested with all 3 coils.

Ron in WV

 

[lloyd0161]

Thanks all for the input,

I am using both the F75 and G2 to work an area. The F75 hunts faster for me and will find almost all items obtainable. The G2 cleans up. I am running the F75 in default mode due to the jewelry mode being too sensitive to EMI in my area. My disc setting is 8 which knocks out most iron and allows me to pick up the really small earrings which are coming in around VID=11. Thanks to Ron for the coil comparison. It appears that I need to get one of the 3.5" x 6.5" coils. I am going to invest in a 9V battery charging system as the G2 eats batteries for lunch. I love the F75 battery life, holy cow this thing is efficient.

 

[therover]

I hear ya on the battery power draw on the G2. Although I had a Gold Bug SE, it was the same thing....battery never lasted as long as I thought it would.

Now the F75....wow. That thing runs forever on a set of batteries.

Also agree the F75 is a faster recovery unit and will go deeper.

 

[therover]

I could not remember what settings/coils you had used to do the test, and was wondering if lloyd0161 had tried JE mode. He responded EMI was a culprit when trying JE. Hopefully he can utilize that mode in some hunting applications where EMI is not an issue because it does have more sensitivity to smaller gold and low conductive targets than DE.