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Recovery Speed Epiphany

TrenchKnife

Full Member
Joined
May 14, 2019
Messages
113
Location
NE US ... CT
Howdy,

After toying with my recovery speed in a trashy spot, I came to understand the purpose of discrimination and "notching out" a lot of signals. of course I'm on an equinox but the recovery speed made a lot of difference in this enlightenment. I basically turned up my recovery speed (to 7), drastically increased my swing rate (there-and-back swing of <1sec) to find the multiple target signals literally pop out.

From this the light bulb went on with the value that notching out could provide, yet I seemed to need a fast swing rate to get the multiple signals revealed (at higher recovery setting). I think I found that with low recovery settings (2-3) the typical 2 second there-and-back swing rate worked best. high settings required fast swings.

I still don't understand recovery speed and I'm mystified with what I found from the source, the horses mouth...

"A higher recovery speed allows you a faster swing rate with less likelyhood of missing a target.

A lower recovery speed for the same swing rate will increase depth but decrease target separation."

-Minelab

Found the vid from this thread, video 23(?) at 1m:10s:
http://metaldetectingforum.com/showthread.php?t=277440


SO ... recovery speed is proportional with swing rate! right? higher swing rate must be accompanied by higher recovery speed maybe?

Which is what setting on an analogous 1-8 second/time scale? is a high recovery speed a high setting at 8 (say 8 recoveries in a second)? is a low recovery setting of 1 a faster recovery speed (1/8 of a second versus 7/8 of second)?

AND how fast is a correct swing rate for each recovery setting/rate/speed ?

-TK
 
Those videos are not actually made by Minelab. There was some paraphrasing of the manual which seemed too generalized and less accurate than the manual.


This is from the Equinox Manual on page 51:

RECOVERY SPEED

By increasing the Recovery Speed, the detector is able to better differentiate between multiple targets that are close together. This assists in high-trash areas with finding smaller desired targets amongst larger iron trash........

While using a higher target Recovery Speed may increase the ability of the detector to find difficult targets, it also results in reduced Target ID accuracy and less detection depth.

SWING RATE

A good general swing rate is around 2-3 seconds from right-to-left-to-right. A higher Recovery Speed generally allows for a faster swing rate with less likelihood of missing targets.

A higher Recovery Speed, for the same swing rate, will help to reject ground noise, but also decrease detection depth. A lower Recovery Speed, for the same swing rate, will increase detection depth, but may increase noise.

If you are experiencing high levels of ground noise at the beach or when detecting underwater try increasing the Recovery Speed to reduce the noise. It is also possible to vary both swing rate and Recovery Speed to help minimize ground noise.

Jeff
 
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A setting of 3 on the Nox is actually its fastest recovery speed, raising it higher doesn't make it quicker, it just shortens the audio report.
 
600-800 recov diff

A setting of 3 on the Nox is actually its fastest recovery speed, raising it higher doesn't make it quicker, it just shortens the audio report.

Ok, I'll go with that, the 800 and 600 functional recovery speed increments are really just in 3rds, but 800 uses 8 button increments to cover what the 600 does in 3. I've now come to find the speed of recovery is likely the minimum time between detectable targets... depending on or relying on swing rate (of 2sec standard)?

I return that the recovery speed per the recovery speed setting is the inverse of setting/8 in seconds (or setting/3 - nox600). this means the increase in setting decreases that minimum time between targets.

I'm not sure I can support the audio report duration conclusion but at this point, it sounds ok.

-point of order-

I detract that my quote came from Minelab. it came from that video, whoever did it. darned if I can tell in that supe'd you toob.
 
Fast recovery speed isn't an invitation to swing like you are threshing wheat. You will get all kinds of unexpected results swinging hyper-fast. Not only are you going to bet broken signals, you are losing a lot of depth.

Ideally, for separation and not losing depth - fast recovery delay, low swing speed. Not slow enough you get multiple hits from the same target, but slow enough you get separation.

On notching - when you notch out, say, 20, your are also mostly notching out 19 and 21, sort of notching out 18 and 22, kinda notching out 17 and 23, etc down to -/+5 of the VDI you notched out. This is just the way filters work. So, if you are looking for something that is 19 or 21, you will tend to get a more broken signal. Same holds true if you notch a VDI you want to pass in a VDI grouping you are discriminating out.

When you use any type of discrimination, you are mulching the original target signal. This can prevent you from hearing very faint signals. The more discrimination you use, the more data your are tearing out of the data stream. Ideally, you shouldn't use discrimination at all. The best discriminator is between your ears. Using it doesn't degrade the target signal.
 
A setting of 3 on the Nox is actually its fastest recovery speed, raising it higher doesn't make it quicker, it just shortens the audio report.

Ok, I'll go with that, the 800 and 600 functional recovery speed increments are really just in 3rds, but 800 uses 8 button increments to cover what the 600 does in 3. .

Citation on these statements?

Neither the text nor the illustration of the two detector recovery speed settings in the manual support them. The illustration clearly shows/says the 800 has a faster maximum speed such that the 600's setting of 3 is the same as a 6 (not 8) on the 800. "...fewer increments and a slower maximum recover speed..."

But, let's say 3/6 is the fastest technical speed and the 7 and 8 on the 800 is achieved by clipping the tones. I'd say "OK, that makes sense." At some point the tones can only come so fast and sustain for so long before the ear can't HEAR each distinct tone. A 3/6 might be the practical limit to how fast it can recover for the next tone, but if the coil is moving so fast or the trash is so close together, clipping the tones would make it possible to hear those distinct tones under fast swinging and/or highly dense trash conditions. The result would be described as a 'faster' experienced, practical speed, even if it's not technically faster based on processing speed.
 

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SO ... recovery speed is proportional with swing rate! right? higher swing rate must be accompanied by higher recovery speed maybe?

Which is what setting on an analogous 1-8 second/time scale? is a high recovery speed a high setting at 8 (say 8 recoveries in a second)? is a low recovery setting of 1 a faster recovery speed (1/8 of a second versus 7/8 of second)?

AND how fast is a correct swing rate for each recovery setting/rate/speed ?

-TK

None of this. It's no more or less that what the manual states. A faster recovery speed --- at the same swing rate --- makes it possible to hear distinct signals in denser trash, but at a loss of ID and depth. As a result, you CAN swing faster and cover more ground, but it's not necessary.

In general, I base the recovery speed on the density of trash and then use a variety of swing speeds.

As far as notching, it looks like you have the 800. Use the tone/volume advanced settings when you can to emphasize or de-emphasize certain segments and then minimal notching/silencing. There is a good reply up above that explains why notching isn't as precise or as good of an idea as it might seem. (Sure, I use it for specific reasons, but not as a general approach.)
 
all good input

This is all good input and I think I'm just gonna have to put in the time to get it better understood.

I also agree with don't notch out anything, but with the higher number of "recovery speed setting" across a multitude of targets, I can see how it can be a benefit. notch out the junk, hear the treasure - so one could imagine.

now with the recover speed itself, the actual speed, I experience a problem. at high "recovery speed setting" (8 on the nox800), my "normal swing speed" is not enough to produce signals. I must increase my swing rate to get signals. the inverse also seems to exhibit similar corelation to swing rate ... a setting of 1 and I need to swing slow or I very few signals (even though I know several are below).

so, again, I think I need more real world swing time while playing with the recovery speed setting to get a better feel. right now, I hang out around the 3-5 setting and seem to be just fine.
 
Recovery speed is the time it takes to clear one target and reset for the next one. A faster recovery speed further limits the machines ability to accurately sample the target , a slower recovery speed allows a slight advantage in depth and accuracy because the detector can get a more accurate sample of the return signal. But it is possible to swing the coil too fast for the recovery speed , when that happens the detector may still be processing the first target when its bombarded with the next one , so each recovery speed setting has its own sweet spot.
 
Ohhhhh...I think of 'recovery speed' a bit differently...That is, how may targets can a person recover and pouch as fast as possible?...

Thats the variable and important skill..developing a really fast and efficient 'recovery speed' no matter what rig you are using...

Example: If a guy can procure 100 acquired targets per hour, he can cram 2 or 3x the volume and experience and overall finds in a shorter amount of time than a guy with a slower recovery speed...pulling maybe 10 per hour tops....

Its all about Recovery Speed!! We dont really have a lot of Time on this Planet, in order to make the most of it, a guy has to be really efficient with recovery speed...!

I run a F70, which as a machine is well known and lauded for its super fast recovery speed...And I am also well known for being a super fast recoverer!

In fact, today I found a quarter under the monkey bars that a kid didnt drop until next week..! Thats FAST! :laughing:
 
Recovery speed is the time it takes to clear one target and reset for the next one. A faster recovery speed further limits the machines ability to accurately sample the target , a slower recovery speed allows a slight advantage in depth and accuracy because the detector can get a more accurate sample of the return signal. But it is possible to swing the coil too fast for the recovery speed , when that happens the detector may still be processing the first target when its bombarded with the next one , so each recovery speed setting has its own sweet spot.

After 8 years with the V3i and its recovery delay setting(recovery delay in Whites and inverse of recovery speed but the same end effect), ohiochris described recovery perfectly.

My Equinox 600 though, with its faster processor, IMO, gives it an easier more efficient detector, without needing so many tweaks. My method for my style, coin shooting mainly, I run setting 2 in RS, 95 percent of the time. The only way I can possibly imagine using the highest setting 3, would have to be in really extreme trash. Even then, the middle setting of 2 with the fast processor, manages everything for me, with confidence.

It gets easy to over think and needlessly over tweak RS. I learned that aspect with my V3i days. The Nox with its processor, is very forgiving, even with seemingly erratic swing speeds. It does for me anyway.

Good explanation Chris
 
I personally like to swing in two-three second intervals, regardless of recovery speed. I find that this works best for me no matter what settings I have. Either that, or it’s just in my head :) I’m still getting the hang of it.
 
I personally like to swing in two-three second intervals, regardless of recovery speed. I find that this works best for me no matter what settings I have. Either that, or it’s just in my head :) I’m still getting the hang of it.

Is that "two-three second intervals" mean in one direction or both combined? A one way sweep that slow would kill me, and in my case, so slow that my machine would miss some general targets which I read great with a 1-2 seconds, in one directionn. I need quicker sweeps in general hunts.
 
Is that "two-three second intervals" mean in one direction or both combined? A one way sweep that slow would kill me.

That’s combined- left to right. Maybe in about 50 years that speed will be acceptable for me on a single sweep haha. Trust me though- if I was moving that slow, it’d kill me too :)

Like you said though, I keep it moving at a pace as to not miss any of the small stuff.
 
Ohhhhh...I think of 'recovery speed' a bit differently...That is, how may targets can a person recover and pouch as fast as possible?...

Thats the variable and important skill..developing a really fast and efficient 'recovery speed' no matter what rig you are using...

Example: If a guy can procure 100 acquired targets per hour, he can cram 2 or 3x the volume and experience and overall finds in a shorter amount of time than a guy with a slower recovery speed...pulling maybe 10 per hour tops....

Its all about Recovery Speed!! We dont really have a lot of Time on this Planet, in order to make the most of it, a guy has to be really efficient with recovery speed...!

I run a F70, which as a machine is well known and lauded for its super fast recovery speed...And I am also well known for being a super fast recoverer!

In fact, today I found a quarter under the monkey bars that a kid didnt drop until next week..! Thats FAST! :laughing:

That's even faster than the guy who can shut off the light switch and be in bed before the lights go out.:lol:
 
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