Rx And Tr Questions

[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...