Threshold Adjustment

[cudamark]

On 2/26/2019 at 6:23 AM, Chase Goldman said:

I have heard threshold blanking even in AM, so not sure if that is just a really weak target or noise attempting to break the threshold.  The way I read it this should not happen if nothing is rejected because if not in gold mode this is not a "true" threshold. I just ignore it as an anomaly.  Would probably not do that in gold mode, though.

Same experience here too. I just attributed it to scattered ground mineralzation, or the tiniest of metal (such as the iron fuzz you get on a scoop magnet at the beach) It doesn't seem to effect the operation of the detector, so, I never investigated it any further. I've tried silent search in all the detectors I've owned that had that option, but, never got used to it. I always use a threshold now. I just think it gives me more information. I don't mind knowing that there is a "bad" target in the ground. It can sometimes alert me to a good target close by. In the past, with some machines, running no threshold would sometimes not respond to a deep, barely perceptible target. It just wouldn't break the threshold to make a sound, whereas, if you have a threshold, you could hear the slight variation in the threshold tone. Since a threshold tone doesn't bother me, I'll continue to use, since it doesn't appear to hurt anything doing so.

[mn90403]

On 9/29/2020 at 10:49 AM, cudamark said:

I don't mind knowing that there is a "bad" target in the ground. It can sometimes alert me to a good target close by.

This is also one of my clues.  I'll dig a bad target to see its size and shape and layer it is in on my beaches.  It slows me down and helps me stay in a patch or find one.  I enhance those 'bad' signals by increasing that iron volume.  It is a target to me with meaning and I can decide to dig it or not.  Sometimes I get blanking on them without a threshold.  A tent spike gives my 800 a fit because of its shape I think. (It screams on my 3030.) It wants to blank and ignore them so I get a partial signal when I interrogate. 

I can't use it that way in all situations, especially the desert looking for gold.  The hot rocks need to be ignored as much as possible so that iron volume is low.

[stevejhgla]

I'm still quite new to metal detecting, only a couple of months so bear with me.  I figured I'd post here instead of making a new thread, since my question is about threshold.

Take the threshold you hear on a sovereign gt:  Is the equinox vdi just a translated version of that into beeps and boops?

I tried using it today in all metal, threshold did not blank when I came across a target.  

 

Marc

[FloridaSon]

See other responses below.....Happy hunting!

[Badger-NH]

Simply put, there is no blanking in all metal because nothing is being discriminated in all metal mode.

Only discriminated targets will cause the Threshold to blank. If you go out of all metal, the Threshold will blank over most iron, as well as any non-ferrous targets that you have notched out.

 

 

 

[Jeff McClendon]

On 10/15/2020 at 9:59 PM, stevejhgla said:

I'm still quite new to metal detecting, only a couple of months so bear with me.  I figured I'd post here instead of making a new thread, since my question is about threshold.

Take the threshold you hear on a sovereign gt:  Is the equinox vdi just a translated version of that into beeps and boops?

I tried using it today in all metal, threshold did not blank when I came across a target.  

 

Marc

Sorry I just saw this post. How I missed it????? The threshold on the Equinox is a reference threshold. It is my understanding that the Equinox reference threshold is separate from the target audio/VDI responses unlike some older detectors where the threshold audio and the actual audio target response were the same audio circuit.

[GB_Amateur]

22 hours ago, Jeff McClendon said:

The threshold on the Equinox is a reference threshold. It is my understanding that the Equinox reference threshold is separate from the target audio/VDI responses unlike some older detectors where the threshold audio and the actual audio target response were the same audio circuit.

Jeff, would you please elaborate on this distinction?  Particularly what are the implications (e.g. advantages and disadvantages) of each type of threshold.

[Jeff McClendon]

I am particularly thinking about pulse induction detectors, some Tesoros and some earlier VLFs that had a threshold based all metal mode. I am not an expert on those types of detectors, I just know that there was very little ability for iron discrimination on those PI detectors except for "low, high, low" or "high, low, high" tone sequences and that the threshold tone would momentarily cease and change amplitude over a target. Something similar would happen with VLF threshold based all metal mode detectors too.

On the Equinox, the threshold tone in all search modes: can be used to indicate that the coil is passing over a notched out or discriminated out target by going silent over those targets, it can have its pitch adjusted separately from the target tones, it can have its volume level adjusted separate from the target tones, and it can be turned off or on without having any effect on the intensity of the target tones.

It can also indicate whether the Equinox is becoming unstable due to changing ground conditions while also nulling out on EMI if it is being detected in a numerical ID range that has been discriminated. 

It has to be turned on to do all of these things and some numerical target IDs have to be discriminated.

Some people have reported that while using the Gold modes, the use of the threshold will enhance the ability to detect and hear deeper non-discriminated targets. I don't have any in the field proof of that. If a little bit of discrimination is being used in high mineralization, deeper gold, brass and lead targets that are having their numerical target IDs pulled down into the iron range by mineralization could be detected due to this nulling. 

[Jeff McClendon]

I did some testing recently and actually did notice that the use of some threshold in the Gold modes will boost the volume of faint signals. Even when the threshold is set on 3 or 4, which for me is inaudible, small mineralization masked gold and lead targets are easier to hear. With the threshold set on 8 or so, which is where I like it since for me, it is only barely audible, those same targets are much easier to hear. I learned something new about the Equinox thanks to this great topic!!!!

The use of the threshold in Park, Field and Beach did not boost the same faint signals however, so I won't get too excited.........