SouthFLdigger
Sr. Member
- Joined
- Mar 16, 2014
- Messages
- 470
- Reaction score
- 344
- Golden Thread
- 0
- Location
- Pembroke Pines, Fl
- Detector(s) used
- Beach:Fisher CZ-20, Beach Hunter ID 9.5" Whites DFX, Minelab Safari and Excalibur 2.
Park and Turf: Teknetics Gamma 6000,Teknetics Delta 4000,Nokta Fors Core
Loaners:ACE-250 9x12 and 7x9.
- Primary Interest:
- All Treasure Hunting
- #1
Thread Owner
Well I was finally able to get out and do some salt water testing for my Nokta Fors Core here in Miami Beach. I have had many VLF machines and have attempted to use them all in the salt water just to see which one best deals with the salty sand here. While many of us are aware that different beaches have varying degrees of impact on VLF and multi-frequency machines, many don’t know exactly why. Miami Beach and Florida beaches In general have very little concentrations of Magnetite or Maghemite . However salt water concentration in Miami Beach are very high. For example the saltiest water (40 o/oo) -- parts per thousand), for which the symbol o/oo is used. That is, a salinity of 35 o/oo means 35 pounds of salt per 1,000 pounds of sea water ) occurs in the Red Sea and the Persian Gulf, where rates of evaporation are very high. The salinity of the ocean water off Miami Beach, Fla., varies from about 34.8 o/oo in October to 36.4 o/oo in May and June. As a result of these very high concentrations of salt, Miami Beach is the gauntlet of salty sand testing for VLF machines. The beaches up north from the Carolinas and up have much less salt concentrations. Very high salt levels like these have a very high tangent loss on the VLF signals sent down and very high loss coefficients. Needless to say, the G2, AT-pro, Gamma, Omega, T2 and Whites MXT pro, GTI2500 I’ve tried all chattered and suffered greatly when attempting to keep gain at a level allowing at least 7-9” of detecting depth on dime/nickels and similar size objects. I purchased the Nokta in hopes of having a machine that works very well on dry land and “good” in salty sand without the pitfalls associated with multi-frequency machines such as deafness to smaller gold, cost and complexity. The very positive reviews of this machine on dry land are quite accurate.
I took the Fors Core out to my usual spot here after reading the manual and giving it a good 20 hours of use on dry land and air testing. As many of you heard the mechanical quality of this machine is very good and the details of its operation have been discussed plenty on the boards.
I started the test by ground balancing the CoRe and as expected a ground balance of 0.0 was imperative for quiet operation even a ground balance of 1-2 would result in noise! I pushed the sensitivity up to 95 with perfectly quiet operation in this very salty wet sand. At sensitivity levels of 97-98, small pieces of very rusted metal would result in 98-99 signal IDs, while scanning the sand, similar to what a hot rock would yield and resulted in instability in some portions of the beach.All air tests match the results posted by Nokta on youtube in DI2 turn on preset just to confirm a properly functioning unit.
I placed a nickel at 8”, 10”, and 12” inches in soaking wet sand and began testing. I did not simply bury the nickel I dug a hole and inserted the nickel through the side of the hole into the sand at these different depth.
At 95 sens, ID mask at 30, COG mode and 0.0 GB the 8” nickel was clear and audible, at 10” it was too faint and resembled noise at 12” no chance. Ground balance this low (0.0) has a significant effect on depth, even a manual ground balance of 12 or higher resulted in 2” improvement in depth on the buried nickels at the same sensitivity however the noise/chatter was unbearable while sweeping over the sand.
At 97 sens ID mask at 30, COG mode and GB at 0.0 the 9” 10” nickels were clearly heard but no ID on the 10” nickel. At 98 Sens the 10” was loud and clear with ID.
At 98-99 sens, stability of the machine suffered greatly and chatter was too much making detecting impossible. However at this sens (99) the 12” nickel was very audible with a very jumpy ID to no id.
So at 95 sens at a GB of 0.0 expect 8” of depth on a gold ring or a nickel with the Fors Core. At 97 sens GB 0.0 expect 10” in wet salty sand. These result are very good for a single frequency VLF machine, almost matching my DFX.
For dry sand this machine in DI2 mode GB at 60, sens at 97-98, mask 30, it will ping a quarter at 12" with the 7x11" coil in my dry sand here in Florida with ID and loud.
I took the Fors Core out to my usual spot here after reading the manual and giving it a good 20 hours of use on dry land and air testing. As many of you heard the mechanical quality of this machine is very good and the details of its operation have been discussed plenty on the boards.
I started the test by ground balancing the CoRe and as expected a ground balance of 0.0 was imperative for quiet operation even a ground balance of 1-2 would result in noise! I pushed the sensitivity up to 95 with perfectly quiet operation in this very salty wet sand. At sensitivity levels of 97-98, small pieces of very rusted metal would result in 98-99 signal IDs, while scanning the sand, similar to what a hot rock would yield and resulted in instability in some portions of the beach.All air tests match the results posted by Nokta on youtube in DI2 turn on preset just to confirm a properly functioning unit.
I placed a nickel at 8”, 10”, and 12” inches in soaking wet sand and began testing. I did not simply bury the nickel I dug a hole and inserted the nickel through the side of the hole into the sand at these different depth.
At 95 sens, ID mask at 30, COG mode and 0.0 GB the 8” nickel was clear and audible, at 10” it was too faint and resembled noise at 12” no chance. Ground balance this low (0.0) has a significant effect on depth, even a manual ground balance of 12 or higher resulted in 2” improvement in depth on the buried nickels at the same sensitivity however the noise/chatter was unbearable while sweeping over the sand.
At 97 sens ID mask at 30, COG mode and GB at 0.0 the 9” 10” nickels were clearly heard but no ID on the 10” nickel. At 98 Sens the 10” was loud and clear with ID.
At 98-99 sens, stability of the machine suffered greatly and chatter was too much making detecting impossible. However at this sens (99) the 12” nickel was very audible with a very jumpy ID to no id.
So at 95 sens at a GB of 0.0 expect 8” of depth on a gold ring or a nickel with the Fors Core. At 97 sens GB 0.0 expect 10” in wet salty sand. These result are very good for a single frequency VLF machine, almost matching my DFX.

For dry sand this machine in DI2 mode GB at 60, sens at 97-98, mask 30, it will ping a quarter at 12" with the 7x11" coil in my dry sand here in Florida with ID and loud.
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