Rx And Tr Questions

[abenson]

My initial thoughts on the Manticore is that it's a beach detector and a good one at that. Very deep at the GSL, and the extra power is obvious when I compare it to the 900. But put it on mineralized ground and that extra power does nothing for it. Where I live most of the ground is 4 bars on an F75, some parts as low as 2 and some as high as 5. I've been doing a bunch of testing between the Manticore, 900 and D2 in my yard and at some local parks (4 bar dirt) and to be honest there is very little difference in depth capabilities between the 3. As far as the 2D screen goes, it's worthless after 5 inches around here, you just as well use the audio and VDI to make a dig decision. I'm also thinking that deep nails are going to be a real problem on the Manticore, but I will save judgement for a later date after I have some more hours on it.

[phrunt]

In the areas I’ve been so far the 2D target trace is doing as advertised to near the edge of detection on coin targets, it’s working well to very good depths, I think for me it’s far better than the early model Nox, I’m unlikely to buy a Nox 900 now, unless it’s better for prospecting it’s a big step backwards I think.

I wouldn’t buy a 900 based on prospecting alone as I don’t use VLFs much anymore for gold except for very specific circumstances and the 800 and 24k have them covered well.

[abenson]

On the beach target trace works good, even on deep targets. Iron so far on the beach has not been a problem either. I'm digging targets down to 14" in depth and finding some good stuff. On land it's a totally different story. I really never thought the target trace would work all that well here anyway from past experience with FBS machines. They also had a weakness for deep nails and deep targets in general. It doesn't bother me that it doesn't work past 5" here. There are plenty of other features I like about the Manticore, for example, all the audio options available, for me to keep it. Even if it becomes a dedicated beach machine.

 

[Steve Herschbach]

23 minutes ago, phrunt said:

In the areas I’ve been so far the 2D target trace is doing as advertised to near the edge of detection on coin targets, it’s working well to very good depths, I think for me it’s far better than the early model Nox, I’m unlikely to buy a Nox 900 now, unless it’s better for prospecting it’s a big step backwards I think.

I wouldn’t buy a 900 based on prospecting alone as I don’t use VLFs much anymore for gold except for very specific circumstances and the 800 and 24k have them covered well.

You are in low mineral ground Simon, that’s the key. White sand beaches and turf are where this machine should shine, or just low mineral ground in general. People in high mineral ground will be just as likely to be wondering what all the fuss is about. Andy is reporting just what I’d expect in his ground, and you are reporting just what I’d expect in your ground.

Kind of puts the YouTube internet tests where you have no idea what the ground is like into perspective. And all the detector wars on the internet with people trying to prove they are right, and the other guy wrong. “Well I’ve used both these detectors and this one is better - you calling me a liar!” Rarely does anyone stop to consider that both sides may be right.

[abenson]

I'm going to add to what I said earlier. I'm not sating 5" is the max depth for these machines, I'm simply saying that target trace is not at all accurate after 5". I can hit a 6" dime with all 3 machines and get enough of a VDI to tell it's something high conductive. At 7" all bets are off. Both the Manticore and 900 report high VDI's almost like iron wrap. The D2 is actually the most stable and reliable it will give mostly no ID but about every third pass will throw up a 91, which is pretty close to what a dime should be on the D2. Target trace is really all over the place, I've seen mixed iron/coin traces, snake like traces from the top to center line and snake like traces that stretch 1/3 of the length across the middle line on deeper pennies and dimes. And yes I have dug nails that report just like a coin.

[Gold Catcher]

I would be interested to hear more about gold in mineralized ground, and how well the target id works with small gold and at what depth. I am considering to upgrade my VLF capabilities, currently I only have the GM. But my sole focus is gold, not relics. The iron meter on the GM is pretty much useless, unless the gold is litterally touching the coil, pinpointer style. Would like to know if the Manticore or 900 id works better.

GM

[Steve Herschbach]

Equinox blows the Monster away for ferrous id, which is one of several reasons why I still have the Equinox and not the Monster. The Monster can hit just a little bit smaller gold, but in all other respects I think the Equinox is the better nugget machine.

[phrunt]

I'd agree with that, the GM became nothing more than a pinpointer when the Nox 800 came along and proved its worth to me.  I am sure the Nox 900 is at least as good as the 800 on gold, if not ever so slightly better with it's higher sensitivity setting and just all around better build quality.

I still think for some reason which I can't explain the Vanquish 540/v12 coil combo with jewellery mode gives me more stable ID's on coins than the Nox 800 with 11" coil on the same targets, and the Nox 800 with 11"  coil gives slightly more stable ID's on the same coins than the Manticore.   Perhaps the Vanquish's secret is the V12 coil.

I think the Manticore is less stable as the larger number spread makes the numbers bounce a little more but the bouncing is to all very close numbers and the 2D target trace is giving me a very tight little ball on the center line.  I can make deep coins false as iron simply by lowering my sensitivity down to 18 or less.

Steve made a great point with his ground rules comment above, a lot less arguments would happen if everyone understood that and were more tolerant of other peoples opinions when they could possibly be in very different ground conditions.

[longbow62]

7 hours ago, abenson said:

My initial thoughts on the Manticore is that it's a beach detector and a good one at that. Very deep at the GSL, and the extra power is obvious when I compare it to the 900. But put it on mineralized ground and that extra power does nothing for it. Where I live most of the ground is 4 bars on an F75, some parts as low as 2 and some as high as 5. I've been doing a bunch of testing between the Manticore, 900 and D2 in my yard and at some local parks (4 bar dirt) and to be honest there is very little difference in depth capabilities between the 3. As far as the 2D screen goes, it's worthless after 5 inches around here, you just as well use the audio and VDI to make a dig decision. I'm also thinking that deep nails are going to be a real problem on the Manticore, but I will save judgement for a later date after I have some more hours on it.

I have lowered my Upper Ferrous to 8, and My Lower Ferrous to 3. On a few 5-6 inch bent heavily rusted nails that I have dug I pretty much knew they were nails. Now could a compromised coin near iron act the same? Maybe I guess but I've yet to dig a coin where I was thinking it's iron. The hotter you run the Manticore the more it tends to false. Turn it down from 26 to 20 and you get more grunts than chirps and good sounding high tones as you circle. Take this with a grain of salt as I only have like 12 hours on the detector, but I think it falses on deep nails about like the Equinox does running F2-0.   

[EL NINO77]

On 1/23/2023 at 2:41 AM, Digalicious said:

Thanks for your thoroughness Steve.

I read your post that you linked. The one titled "Selectable frequency and multi frequency". Umm ya, a rabbit hole indeed! I enjoy knowing as much as I can about how detectors work, but I don't want to get that deep into 🙂 

So without wanting to get into that any further, I just have 1 last basic question:

If transmit power is so high that it causes that "blowback", can that blowback be reduced by decreasing the receivers gain, instead of reducing transmit power?
 

Another one of the basic principles in increasing the TX performance... is certainly the reduction of the gain in the receiving part of the RX signal... and then the detector can work effectively even in relatively strongly mineralized soil...

I had no problem running the Whites  Spectra V3 in mineralized soil /6-bar/ with TX boost ON and a very low RX gain of 1-2 max!!!.. with really good detection results...

Another advantage when increasing the TX is... that some types of terrain can greatly dampen the transmitting TX signal... ,, and increasing the RX gain itself "has no effect.. because from the very increase of RX gain on the receiving coil .. .of course you also increase the earth's mineralization response and Emi's response...

I will give an example with the Whites Spectra V3... where when the TX boost is turned on, the detection properties of this detector can be improved very significantly... in a certain area... and which you will never achieve when using TX Normal...

Now to the sensitivity setting for Manticore, which has settings up to 35 max....

Keep in mind that the Manticore will also use smaller coils than the standard 11" coil... and therefore it is possible that on smaller coils you will be able to set a slightly higher sensitivity than is possible with an 11" standard coil in the given terrain... I say so from experience with Equinox and other detectors I own...