Jump to content
Sign in to follow this  
calabash digger

Excalibur 2 And Equinox On Deep Silver And Gold..

Recommended Posts


Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Similar Content

    • By Steve Herschbach
      Which metal detectors have the most reliable target ID numbers?
      Target ID is a function of depth - the deeper the target, the more difficult it is to get a clean target ID as the ground signal interferes. Other items directly adjacent to the desired target can also cause inaccurate numbers. The more conductive the item, the higher the resulting ID number, but also the larger the item the higher the number. Silver is more conductive than gold, so a gold item will give a lower number than the same size silver item. But a very large gold item can give a higher number than a small silver item, so numbers do not identify types of metal. Gold and aluminum read the same and vary in size so to dig one you dig the other. Only mass produced items like coins produce numbers that are more or less the same over the years but a zinc penny will read lower than a copper penny due to the change in composition.
      In general iron or ferrous targets produce negative numbers or low numbers. Aluminum, gold, and US nickels produce mid-range numbers. And most other US coins produce high numbers. Other countries coins, like Canadian coins with ferrous content, can read all over the place.
      The scale applied varies according to manufacturer so the number produced by each detector will vary according to the scale used. The 0-100 range for non-ferrous targets is most common but there are others. Minelab employs a dual number system on a 2D scale with thousands of possible numbers, but they are now normalizing the results produced to conform more closely to the linear scale used by other manufacturers.

      White's Visual Discrimination Identification (VDI) Scale
      Increasing ground mineralization has a huge effect on the ability to get a good target ID. Ground mineralization is nearly always from iron mineralization, and this tends to make weak targets, whether very small targets or very deep targets, misidentify. The target numbers get dragged lower, and many non-ferrous targets will eventually be identified as iron if buried deep enough. Small non-ferrous readings and iron readings actually overlap. That is why any discrimination at all is particularly risky for gold nugget hunters.
      If you want target ID numbers to settle down, lower sensitivity and practice consistent coil control. The target number will often vary depending on how well the target is centered and how fast the coil moves.
      Higher sensitivity settings lead to jumpier numbers as the detectors become less stable at higher levels. The interference from the ground signal increases and interference from outside electrical sources also increases, leading to less stable numbers.
      Higher frequency detectors are inherently more sensitive and are jumpier. So lean lower frequency for more solid results. Multi frequency detectors act like low frequency detectors and tend to have more solid target numbers due to the ability to analyze a target with different frequencies.
      Another issue is the number of target categories, or ID segments, or VDIs, or notches, or bins (all names for the same thing) that a detector offers.
      For instance here are the number of possible target id categories or segments each detector below offers:
      Fisher CZ-3D = 7
      Garrett Ace 250 = 12
      Minelab X-Terra 305 = 12
      Minelab X-Terra 505 = 19
      Minelab X-Terra 705 = 28
      Minelab Equinox = 50
      Fisher F75 (and many other models) = 99
      White's MXT (and many other models) = 190
      Minelab CTX 3030 = 1750
      Fewer target categories means more possible items get lumped together under a single reading, but that the reading is more stable. Many detectors will tell you the difference between a dime and a quarter. The Fisher CZ assumes you want to dig both so puts them under one segment along with most other coins.
      People who use detectors with many target numbers usually just watch the numbers jump around and mentally average the results. Some high end detectors can actually do this averaging for you! But I think there is something to be said for owning a detector that simplifies things and offers less possible numbers to start with. The old Fisher CZ method still appeals to me, especially for coin detecting. So do detectors like the Garrett Ace 250 or Minelab X-Terra 505 for the same reason.
      The problem is that as people strive to dig deeper targets or smaller targets the numbers will always get less reliable. But if you want to have a quiet performing metal detecting with solid, reliable target numbers look more for coin type detectors running at lower frequencies under 10 kHz or at multiple frequencies and possibly consider getting a detector with fewer possible target segments. And with any detector no matter what just back that sensitivity setting off and you will get more reliable target numbers.
      ads by Amazon...
      Detectors often use tones to identify targets and often use far fewer tones than indicated by the possible visual target id numbers. The X-Terra 705 for instance can use 28 tones, one for each segment. However, most people find this too busy, and so simple tone schemes of two, three, or four tones may be selected. I think it is instructive that many people often end up ignoring screen readings and hunting by ear, using just a few tones. This ends up just being an ultra basic target id system much like the simpler units offer. Reality is that most people do not need or care about huge numbers of target numbers. For many just three ranges suffice, low tone for iron, mid tone for most gold items, and high tone for most US coins. The meter could do the same thing, but for marketing purposes more is better and so we get sold on detectors with hundreds of possible target ID numbers. Perhaps this is a digital representation of an old analog meter with its nearly infinite range of response but the reality is we do not need that level of differentiation to make a simple dig or no dig decision.
      Finally, a picture often says it all. Below we have a shot of the White's M6 meter. I like it because the decal below illustrates a lot. You see the possible numerical range of -95 to 95 laid out in the middle. Over it is the simplified iron/gold/silver range. Note the slants where they overlap to indicate the readings really do overlap. Then you get the probable target icons. -95 is noted as "hot rock" because many do read there.

      The M6 can generate 7 tones depending on the target category. I have added red lines to the image to show where these tones sit in relation to the scale. It breaks down as follows:
      -95 = 57 Hz (Very Low) Hot Rock
      -94 to -6 = 128 Hz (Low) Iron Junk
      -5 to 7 = 145 Hz (Med Low) Gold Earrings, Chains - Foil
      8 to 26 = 182 Hz (Medium) Women's Gold Rings/Nickel - Small Pull Tabs
      27 to 49 = 259 Hz (Med Hi) Men's Gold Rings - Large Pull Tabs
      50 to 70 = 411 Hz (High) Zinc Penny/Indian Head Penny - Screw Caps
      71 to 95 = 900 Hz (Very High) Copper Penny/Dime/Quarter/Dollar
      Note that the screen reading of +14 is noted as being a nickel or ring but it can also be the "beaver tail" part of an aluminum pull tab or the aluminum ring that holds an eraser on a pencil, among other things.
      The best book ever written on the subject of discrimination is "Taking A Closer Look At Metal Detector Discrimination" by Robert C. Brockett. It is out of print but if you find a copy grab it, assuming the topic interests you.
      Always remember - when in doubt, dig it out! Your eyes are the best target ID method available.


    • By karelian
      The passing of a friend unfortunately has led to me taking ownership of a modified Tdi Pro. My machine is mounted on an Anderson shaft and is factory spec. My old mate had his machine modified to smooth out the threshold and to add some sensitivity. The specifics related to the modifications are not known by me, other than that they were conducted by 'Luke'..Oz Digger.. This happened some time ago. So the modified machine is probably not a keeper, I don't want two Tdi Pro machines.. The opportunity to do a comparison cannot and should not be ignored. 
      My intention is to focus on small gold performance, the threshold smoothness, the ability to use gain, basic performance and handling characteristics  under different circumstances. The machines will use the same fully charged battery pack, same coil, same targets, same test location and conditions on the same day etc. Trying to minimise external variations. I'll start with the usual useless air test. Later I'll follow up with in ground testing on the actual goldfields in mineralized soil. Test coils will be with a small coil and a large coil. Targets will be gold only. The 1 grain ingot, the half gram gold coin, a half sovereign gold coin. Some real small sub gram nuggets to see how small we can go.. There is a process involved so I'll take my time and do it right.  Any specific questions or suggestions, speak now or forever hold you peace.. I'm only doing this once. Once it sold it will be too late to revisit.. 
      All the best.

    • By Steve Herschbach
      Update January 2019 - I started reviewing detectors on the internet over twenty years ago. At the time it seemed I was providing a service since good information was hard to find. I enjoyed reviewing machines in detail for those who were interested. The internet was more friendly back in those days.
      Times have changed, and these days everyone with a video camera is a metal detector expert. In particular there is a trend where industry insiders like me are considered tainted sources of information, not to be trusted. Personally, I don’t need people questioning my integrity. I was doing this for fun and that sucked all the fun out of it. I am therefore no longer accepting invitations to review metal detecting equipment. I may continue to work with engineers on product development but in general will recuse myself from publicly discussing the equipment involved. If anyone wants to use me as part of their marketing efforts they can hire me outright. I'm available and will consider job offers that involve the sales and marketing of metal detectors.
      My thanks to those of you who have expressed your appreciation for my efforts over the years. You can find my collected detector reports here. The focus on this website going forward will be individual user reviews as part of the new Metal Detector Database with User Reviews. Check it out! 

       
    • By Tnsharpshooter
      Another hunt with Tarsacci today.  Found some relics mostly musket balls.  First target of the day located with Tarsacci I did head head to head with XP Deus wearing 9” Hf coil.
      Only head to head done today.
      You will hear in this video where I actually had Deus ground balanced using 14 kHz.  A 72 was in phase window.  I disn’t  do another GB when switching to 28.8khz.  As I had no clean place close to do.  In my ground if I would have done GB at 28.8khz what I usually see is a phase reading 3 points below what pumping GB shows for 14 KHz.  So imo the GB being off a mere 3 points approx didn’t have anything to do with Deus struggling to get targett from the one direction using 28 kHz (especially after seeing depth of target recovered).  Both Tarsacci and Deus Hf coils here are 9” wide but Tarsacci Coil is longer.  Tarsacci is no slouch in iron.
      This object found checked with magnet and is totally nonferrous.
      Will post a pic of closeup.


    • By Tnsharpshooter
      Two videos.
      I have used the term iron range when talking of Etrac here loosely.  I recommend folks wanting more info if necessary to refer to Etrac User’s Manual and look closely at factory relic program to get a better idea of where ferrous reports in relation to the conductive line perspective wise.
      Etrac was run in videos at 50 conductive tones,
      Tarsacci sensitivty setting at level 6.
      All detectors balanced to actual ground except Etrac, but swept Etrac a little beforehand to insure ground tracking was good.
      Most of these targets are I think challenged in one fashion or another.
      Enjoy
       
    • By mn90403
      Most of us have had several detectors in our hunting careers.  Some have been good to us and we've paid for the detector many times over.  Other detectors have been so so.  I'm going to make a list of detectors that I own or owned and say which ones paid for themselves.  Some of this depends on just getting better or lucky at detecting and some depends on the detector itself.  I'm trying to give maximum credit to the detector.
      GOLD DETECTORS
      Minelab 5000                Yes
      Minelab 2300                No
      Minelab 7000                No
      Gold Bug Pro                 No
       
      BEACH AND RELIC DETECTORS
      White's 6000 Di Pro      No
      Minelab SE Pro             Yes
      CTX 3030                      Yes
      Minelab Equinox          Yes
×
×
  • Create New...