Title: Some in the ground tests with the Teknetics T2 Ltd Post by: Rob Two Spades on April 07, 2011, 11:15:58 AM This test is copied from Thomas Dankowski Open Forum, I thought it useful to T2 owners.
I tried the same test with a 5p in pasture and got the same results. Notice the bizarre improvement in depth at sensitivity 60, discrimination 50! Not what I would expect, I got exactly the same anomaly. I also got the same depths when I replaced the 5p with an Eddy hammered penny., about the same size I suppose. Using a 14 month old T2 LTD, 11''coil, a small C/nickle coin @55, a lead .177 air-gun slug @43 in air test. Done by hand so a bit raggy. IN GROUND TEST ...........................................Sens....43.............................55 Disc................................................177cal.......................Cupro/Nickle Coin.....(British 5 pence) 0 ....................................................5''.............................11.5" 1 ....................................................4...............................11 2 ....................................................3.75..........................10.5 3.....................................................3.50..........................10 4.....................................................3.25.......................... 9 5.....................................................2............................... 9 6.....................................................1.25.......................... 8.50 7.....................................................1............................... 8.50 8.....................................................1................................8.25................Signals start to get louder, cut off abruptly. 9.....................................................1................................8.25 10...................................................75..............................8.....................that's a .75 result, not 75 15...................................................0................................7 20...................................................0................................6.25 Disc....................................Sens.....................177cal..........................Cupro/Nickle Coin.....(British 5 pence) 20.......................................99........................3".................................10" 20.......................................90........................1...................................9.25 20.......................................80........................0...................................8.25 30.......................................60........................0...................................6.25 40....................................... ''.........................0...................................6 50.......................................''..........................0...................................10.50 Bp mode. 0.........................................40........................4.50"..............................12+" 1.........................................''..........................5.....................................12 2.........................................''..........................4.....................................11.75 3.........................................''..........................3.50................................11.75 4.........................................''..........................3.25................................11.50 5.........................................''..........................3.25................................11.0 6.........................................''..........................3.....................................10.75 7.........................................''..........................2.50................................10.50 8.........................................''..........................2.50................................10.50 9.........................................''..........................2.....................................10.25 10.......................................''..........................2.....................................10.0 15.......................................''..........................1......................................9.25 15......................................60.........................0......................................9.50 15......................................70.........................0......................................10.50 20......................................70.........................0......................................9.50 20......................................80.........................0......................................10.50 50......................................60.........................0......................................11 I don't understand what you mean when you say disc don't lose any depth. The figures are a bit rough but my test bed shows basically the same pattern,.... after a disc of 8 the signal tones get what appears a gain (louder) but it cuts off fast, as in,, it's there loud at full detection depth,,,, move the coil away a fraction no fade,,,, just gone. 50 disc seems to take it back to 2 disc, it chatters just the same. Sorry about that, don't know why it's crushed all the columns up. TerraDigger's results re-posted from "Teknetics T2 / A Gain Measurement Chart": ""Keep In Mind Indoor EMI Affects The Depth/Noise Results. Test Is Only To Show How Discrimination Adjustments on T2 Affect The Gain (or something that acts like gain) Output"" AIR TEST Model - Teknetics T2/Software version 6.5 (from 6.0 onwards version numbers make no difference in depth according to First Texas Products) Coin Used - U.S. Quarter - Cupronickel Coil - 5" DD Sensitivity - 60 Tone Selection - 4 Discrimination Levels 0 - 9" depth reading (extremely noisy due to EMI & machines internal circuitry noise) 10 - 7" depth reading (approx 50% less noise than 0 disc setting) 21 - 6 1/2" depth reading (quiet) 30 - 6" depth reading (quiet) 40 - 6" depth reading (quiet) 49 - 5 1/2" depth reading (quiet) 50 - 9" depth reading (this is where another huge increase in Gain occurs, besides the zero setting. Same noise level as 0 disc setting) 60 - 9" depth reading (approx 50% less noise than 50 disc setting) 70 - 8 1/2" depth reading (quiet) 80 - 8" depth reading (quiet) Observation - the Gain does not seem to follow a straight linear output as disc is increased. Notice that from 0-49 disc there is a 3 1/2" range in detection depth. From 50-80 disc there is a 1" range. 0r If you remove the disc 0-9 results from above, there is a 1 1/2" depth range between disc 10-49 and a 1" depth range between disc 50-80. The large gain increase at 50 and the 10-49 disc range has serious implications on how a user sets the discrimination. Coin specifications used in both tests: Value........5 pence British Mass.........3.25 g Diameter...18 mm Thickness..1.7 mm Comp........75%.Cu...25%.Ni Value........5 cents U.S. Mass.........5.0 g Diameter...21.21 mm Thickness..1.95 mm Comp........75%.Cu...25%.Ni Title: Re: Some in the ground tests with the Teknetics T2 Ltd Post by: Dodger on April 08, 2011, 09:29:16 PM I have a T2 and found an American forum which said exactly what you have, that increasing disc past 50 will increase depth. I haven't tried it yet but someone on one of the Scottish forums has found the same. Increased discrimination = increased depth. Goes against what we all believe that increasing disc will decrease depth. Any thoughts??
Title: Re: Some in the ground tests with the Teknetics T2 Ltd Post by: Rob Two Spades on April 09, 2011, 09:21:20 PM Yes, it is odd but having discriminate on 50 gives you more depth than having it on 10, in fact its about the same as 7. I tested it and sure enough its true. Try yourself.
On good pasture I run it on Tones 1, Sens 80, Disc 50. Its quiet and very deep. On iron infested soil though I prefer Tones 2+, Sense 60, Disc 4 so I can hear everthing. If its really bad I'll use All Metals, Sens 45, in bP tones mode Title: Re: Some in the ground tests with the Teknetics T2 Ltd Post by: Grant on October 05, 2011, 11:57:53 AM I have a T2 and found an American forum which said exactly what you have, that increasing disc past 50 will increase depth. I haven't tried it yet but someone on one of the Scottish forums has found the same. Increased discrimination = increased depth. Goes against what we all believe that increasing disc will decrease depth. Any thoughts?? Any more thoughts on this? I've only just got a T2 so am trying to find all the info that I can.. I thought only decreasing Sensitivity decreased depth, not discrim with the etrac anyway |