By Steve Herschbach
It was just this spring that I noted the price for the Minelab X-Terra 705 had dropped to $600. I thought that was good, but somewhere along the way the price dropped again to $499. As of today I find these internet prices...
X-Terra 305 $259
X-Terra 505 $349
X-Terra 705 $499
This makes sense with the new Equinox 600 coming in at $649 and Equinox 800 at $899. The X-Terra 705 can be had standard with a 7.5 kHz 9" round concentric coil for $499 or you can also get it standard with a 18.75 kHz 5.5" x 10" elliptical DD coil for $499. The higher frequency elliptical coil variant is known as the X-Terra 705 Gold. Note that the X-Terra can change frequencies by changing coils so owners of either version can have the other by buying the appropriate coil.
I don’t think there is another detector out there that matches the X-Terra 705 for features at $499 and it has an excellent threshold based all metal VLF Prospecting Mode. In particular the X-Terra 705 has every ground balance option possible - Ground Grab, Manual Ground Balance, and Ground Tracking with Tracking Offset. It also has a special Beach Mode that allows it to properly ground balance to wet salt sand conditions.
The $500 segment is really heating up!
Understanding Your X-Terra by Randy Horton is a free 95 page color booklet on how to get the most out of your Minelab X-Terra but with information that owners of any metal detector will find valuable.
Minelab X-Terra 705 Field Guide
Minelab X-Terra 705 Owner's Manual / Instruction Guide
A nice woodland hunt video where I found 6 nice coins with the oldest dating back to 1908. Along with the coins I found a couple of bullets, rifle casings, toy guns and a few other bits and bobs. The metal detecting dig was done with my Minelab X-Terra metal detector which I've been using the last couple of months and the Minelab X-Terra hasn't let me down yet. There is a photo of the coins at the end of the video showing more detail and I'll be back out with the xterra 705 soon.
I had been running my threshold setting at 7 to get the slight hum in my phones and it finally dawned on me this is not an optimum setting for picking up deeper fainter signals since a setting closer to 0 should be best. Having always ran the detector volume control in the upper ranges and using the headphones to control the audio level, I decided to switch it around by setting the headphones to max and using the detectors volume control to set the overall audio level. This made a huge difference, now I can get that same slight hum with a threshold setting of 2. Subjectively there seems to be much less modulation on the deeper targets where now coins in the 10"+ range are much louder hits. I'm also running the detector volume control at 4 to 5 to get the same audio volume I was getting before with it set in the mid 20's.
OK so I decided to do some air tests to see what difference there is in audio modulation and on coin size targets there is a difference in audio the last few inches.
First number is a full audio report distance (or as close as my ears perceive it), second number is the distance target lost. The difference between is the amount of audio modulation where the target volume decreases to the point the signal is lost.
The first column is with the headphone volume at max and threshold audible at 1 setting (0 is silent), second column is detector volume at max with threshold at 7 (6 silent)
Headphones max......................-... Detector max dime............. .............9" /10" ...- ..7" / 10" Buff nickel......9-1/2" / 10-1/2" ...-.. 8" / 10-1/2" IH penney..........10" / 10-1/2"....-....9" / 10-1/2" As we see there is no difference in detection distance between the 2 settings but a more modulated audio response with the detector volume at max.
I also tried the dime with the detector volume at max with a 0 threshold setting and the results were a full volume report to 6" with a max detectable distance of 9", for a 1" loss. Because of this it is apparent that ML has designed the threshold level to follow the volume setting (7 equals 1) which would allow max sensitivity when the detector is used without headphones in cases where a high volume setting is needed to overcome ambient noise. The loss of response on the dime indicating a negative threshold setting because at this volume setting 6 is actually zero.
Since these were coin sized targets and not tiny nuggets the difference could be even bigger when nugget hunting.
This is primarily a coin and jewelry hunting topic, I think. Getting more experience with different detectors, I'm wondering if I'm seeing a common (but hopefully not guaranteed) issue. What I'm referring to is called 'wrap-around' and I'm sure it has other names. Basically the low end of the induction balance (IB) ID scale is low conductivity iron and high end is pure silver. But sometimes with iron you get a high ID, usually in conjunction with the low ID. I've had this happen on three detectors but don't remember it on a 4th. The three are: White's DFX-300 w/ 950 concentric coil (least experience), Teknetics Gamma 6000 w/ egg-shaped conc. coil (intermediate experience), and Minelab X-Terra 705 w/ both 7.5 kHz 8.5" round conc. stock coil and Coiltek 3.0 kHz 6" round DD "Digger". I don't remember this problem with my Gold Bug Pro with any coil. I go into detail here with the 705 because I've used it the most in iron infested sites.
The lowest ID on the 705 is -8 and the highest is 48. (All even numbers except 0 in between occur but never odd numbers -- by design.) Iron is anything below 0; high conductive coins (Cu and Ag alloys) are above 35 (usually) with silver dollar being highest US coin at 46. (Don't know what a pure silver round would read, maybe 48, but who drops those?? ) In the US Midwest we mostly have moderately low iron content (at least compared to US West) -- may be exceptions in iron mining areas like Minnesota and Michigan Upper Peninsula. I've seen phase auto at 35 with the 7.5kHz coil and 8 or 9 with 3 kHz "Digger" (don't know why the disparity...). I run max tones (~30 of them?) in "Coin and Jewelry" discriminate and alternate between "all metal" and notching Off below 0 and also notching Off 48. Note: this detector has a prospect mode but that operates quite differently and I haven't used it for hunting coins, although I see that some have.
Even with the notching described above I get 46's and even 44's on iron targets. In all metal I can hear the jumping between iron ID's and high conductive ID's, but this can (and does!) happen when you're going over a coin near a nail, for example. The hope was that I could listen to tones and not have to look at the screen, but that doesn't seem to work well for me in the iron infested parks I hunt. I'm sure with more experience (and, yes, I've read Randy Horton's "Understanding the X-Terra" multiple times) I'll get better, but I still find myself, even in max tones, having to look down at the screen way more than I would like.
So I guess I have a two part question: 1) is this an inherent problem in all coin hunting and multipurpose IB detectors, and if not, which ones are immune to it? 2) Do you have tricks, besides over-notching, to work around this problem? I've found enough old coins that I don't want to notch out halves (ID=44), because I know, although rare, they are out there. Lastly, I'm not interested in modern coins, although those come with the territory. So far I've found old coins at shallow depths (4 inches or less) and none deeper, although I'm sure they are there. I dig lots of pulltabs (square but mostly ring & beavertails) and don't mind that. There are coins in that zone and I'm willing to put up with the Al in order to find them.
By Steve Herschbach
People send me emails or PMs asking questions and I now have a new policy whereby I will post and answer the question on the forum, then aim them at the answer on the forum (names left out). The whole point of asking questions on a forum is everyone gets to share the answer, plus other opinions can be sought. That gets lost with email and PM.
"Regarding the Racer 2, I know you will point me in the right direction, I am looking for a Racer 2 or the X-Terra 705, will be doing coin and jewelry hunting as some beach hunting (two or three times a year) in dry and wet sand, so which one do you recommend? Or do you think they are about the same?"
They are very similar detectors in a lot of ways and having used both I don’t think either has any particular magic ability over the other. Nothing a more casual user would perhaps discern anyway. If you are really into your detectors there are feature differences that may or may not be important to you so look carefully at the feature list of both detectors. For instance, if you are into tones, the Racer 2 has mono tone, two tone, or three tone hunt modes. The 705 has mono tone, dual tone, three tone, four tone, and 28 tone modes. However, on the X-Terra how those tones are laid out is preset and cannot be modified. The Racer 2 lets you shift the ranges on the two tone and three tone modes and even change the pitch of the sounds. So while the Racer 2 has a limit on the number of tones within those limits it has more ability to be customized. I like that. I also like full tones so the 28 tones on the 705 appeals to me. That is the sort of stuff one has to weigh.
These are the sorts of things that matter to me and that I look at. People always talk about depth and that is a waste of time discussing in most cases. It varies due to the ground minerals at each location and all VLF detectors worth the name are so close it results in endless debates. It is just hair splitting. Now when it comes to picking out different closely spaced items one from the other the Racer 2 has an edge from being a faster response detector. This can help if picking through dense trash. But again, that is more a feature expert hunters appreciate.
The Racer 2 runs at 14 kHz. The 705 can be had stock in 7.5 kHz or 18.75 kHz versions, and customized via coil options to run at 3, 7.5, or 18.75 kHz. This seems impressive but in real life has not been a huge factor with the X-Terra because having to change coils to change frequencies is cumbersome. Still, if chasing small gold nuggets was an issue the 705 at 18.75 kHz might have an edge though the Racer 2 is surprisingly hot for 14 kHz.
The bottom line is it is like having me try and choose between two different sets of similar hiking boots for you. They are too close to tell which will fit you better and either way I could be wrong. I can use either detector and be happy. My best advice is scrutinize the feature list and both owner manuals online and see if any feature really pops out at you as being something you care about.
I'm considering buying (yet) another coil for my ML X-terra 705 -- 15 inch DD operating at 3kHz. Often Minelab and Coiltek offer complementary (different size/frequency/winding) coils, but in some cases, as what I'm considering, they offer coils that appear to be quite similar. Given that the Coiltek costs about 50% more, I'm wondering if I should apply the "you get what you pay for" standard advice or save $100 for a future coil purchase.