X-terra 505 Not For Prospecting?

[GB_Amateur]

Minelab's site/advertising lists the 505 applications as "coin, relic, jewelry and beach".  For the 705 it adds "gold prospecting".  But when you look over the details and specs for the two instruments, it's hard (for me) to see the distinction.  Both have all metal mode as well as discriminate mode.  Both operate at 3 kHz, 7.5 kHz, and 18.75 kHz (all determined by the coil you choose to attach).  Both have manual ground balancing (705 also has automatic and tracking in addition).  Both have adjustable threshold and adjustable sensitivity.  Both have fine-tunable frequency to eliminate EMI.

The Minelab site list something called "detect modes" where the 505 says (1) "Coin and Treasure" while the 705 lists (2), that plus "Prospecting".  Are these preprogrammed setup options?

For some of the adjustable settings the 705 has higher precision than the 505.  An example is the Ground Balance where the 505 says "0 to 50" and the 705 "1 to 90".  Sensitivity is another example:  1 to 20 vs. 1 to 30.  Pinpointing is more detailed on the 705, and the 505 doesn't have backlighting.  Discrimination divisions can be configured to a higher level (iron mask on the 705 and more segments).  So, yes, the 705 does have more detailed features.  But what distinguishes the 705 as a prospecting detector compared to the 505 (for which the Minelab site's implication is that the 505 isn't a prospecting detector).  And if one were to compare the 505 to competition from Garrett (AT Gold) and Fisher (Gold Bug family) to name just two, what makes those prospecting detectors and leaves the 505 in the "coin and treasure" (only) category?

BTW, I did read Randy Horton's "Understanding your x-terra" monograph and he does talk about the prospecting mode of the 705, but it's not clear that one couldn't configure the 505 to be close to these settings.

[Steve Herschbach]

The short answer is that the X-Terra 505 does not have a true unfiltered threshold based all metal mode. All Metal mode on the 505 is a disc mode with all notches (bins) set to accept. However, it is still being filtered through the disc circuit. On the 705 Prospecting Mode is a true unfiltered all metal mode.

That is not to say the 505 can't find gold nuggets. If it was all I had I would use it. It should easily hit half gram stuff in real ground. However, anyone reasonably serious about gold prospecting should get a detector that was made specifically for the task.

I will comment further in a new thread about the confusion on what constitutes an all metal mode because it messes a lot of people up.

[GB_Amateur]

13 hours ago, Steve Herschbach said:

The short answer is that the X-Terra 505 does not have a true unfiltered threshold based all metal mode. All Metal mode on the 505 is a disc mode with all notches (bins) set to accept. However, it is still being filtered through the disc circuit. On the 705 Prospecting Mode is a true unfiltered all metal mode.

Thanks, Steve.  I reviewed the Minelab webpage for the 505 and unfortunately they don't mention this.  Similarly when they let you compare multiple models side-by-side (e.g. 505 vs. 705) they also fail to point this out.  In both cases they state "All Metal" modes.  By contrast, in the Garrett catalog when comparing the Pro vs. the Gold models, Garrett does an excellent job making the point that the Gold has "True All-Metal Mode" as opposed to the Pro which it notes does not.

[Steve Herschbach]

Terms and definitions. Minelabs page tells you directly to look at the 705 as being appropriate for prospecting. It does not include that use when defining the 505. That is clue number one.

Both detectors do - under discriminate options - show a "all notches set to accept" all metal disc mode. That's true.

Coin and Treasure Mode is Minelabs disc mode.

Prospecting Mode is Minelabs unfiltered threshold based all metal mode.

The 505 only has the Coin and Treasure Mode. The 705 adds the Prospecting Mode.

I would agree Garrett does a better job explaining it comparing the AT Pro to the AT Gold.

Garrett also touts nearly all the Ace models as having an "all metal" or "zero discriminate" mode when in fact those machines only have disc modes set to accept all items. As I noted before, it is an area of common confusion when discussing multi purpose detectors. If I recall correctly Garrett was one of the original sources of this confusion. The Ace 350 for example lists Prospecting as an appropriate use. This although it runs at 8.25 kHz and lacks a true unfiltered threshold based all metal mode. But it is listed as having one of these fake "all metal" modes that might lead people to believe they are getting something they are not. I personally would not list the Ace 350 as being prospecting appropriate.

Which is why how all metal modes are listed is a pet peeve of mine, along with many non-ground balancing beach pulse induction machines being listed as having "automatic ground rejection" when they do nothing of the sort.

The basic qualifications for a prospecting capable VLF is that it run at 12 kHz or higher, that the operator must be able to adjust the ground balance, and that it has a true unfiltered threshold based all metal mode. I can find gold nuggets with any detector that shares these three characteristics.