Yet another Correlate question.....

[MO-searcher]

I have a question about the V3i correlate mode. I'm trying to determine what sequence correlate uses to compare the three frequencies.

For instance, does it first determine which frequency has the strongest signal "the best data frequency" and then compare that against the two other frequencies, looking for a match based on Span and Wrap? Or does it only use the top two frequencies based on signal strength, ignoring the weakest channel? Or lets say that the two weaker channels are a match, coming in at +81 and +83 well within a Span set at (21), does it ignore the strongest channel which for this example I'll say is -79, in favor of a match between of the weaker two? In whichever case is correct, what VDI would be reported, the one associated with the highest signal strength of the two correlated frequencies?

Hey, it's mid summer and the ground is like concrete, so I'm taking a break and using the time to try to better understand my V3i.

My guess would be that it compares the strongest signal against the other two, looking for a match and reporting the VDI number of the strongest channel, but would like to know for sure in order to better understand how to use this feature.

Thanks,
Steve - Missouri

 

[Rob (IL)]

If you set the span to 30,it means the two hardest hitting frequencies must have no more than a difference of 30 between them. 35 means the two frequency Vdi can be more different from each other and will still give a signal. 25 the two vdi would have to be closer to give a signal. You are setting a difference range.

 

[MO-searcher]

Rob,

Thanks for the quick reply. Your explanation makes perfect sense and helps clear things up for me.

So a response will be triggered only if the two strongest signals fall within the parameters I set, meaning the Span and Wrap. In my example, even though two frequencies were within the span I set, the V3i would remain silent as the hardest hitting frequency was outside the range of the other two.

I asked this question because it can be difficult to tell what is happening as the bars flash across the Spectra-graph screen. Sometimes I do encounter the situation I described above, where a deep target is strongest at 22.5 and showing in the iron range on the graph while both 7.5 and 2.5 are also showing solid bars but in the dime/quarter/half range. If I get a quick audio hit and see this on the screen, I stop and investigate the signal further. If I can get a repeatable response I will pinpoint, and if a coin, it will normally show 2.5 dominant.

I normally stick with Best Data, but find that Correlate can be useful in areas with lots of deep rusty iron targets, as long as I take it slow with a recovery setting in the 85-95 range.

Thanks again,
Steve

 

[Rob (IL)]

Rob,

Thanks for the quick reply. Your explanation makes perfect sense and helps clear things up for me.

So a response will be triggered only if the two strongest signals fall within the parameters I set, meaning the Span and Wrap. (Span not wrap) In my example, even though two frequencies were within the span I set, the V3i would remain silent as the hardest hitting frequency was outside the range of the other two. The hardest hitting frequency would be noted and then it would check and see if the second frequency was within the span you set. In my example within 30 of the hardest hitting frequency.

I asked this question because it can be difficult to tell what is happening as the bars flash across the Spectra-graph screen. Sometimes I do encounter the situation I described above, where a deep target is strongest at 22.5 and showing in the iron range on the graph while both 7.5 and 2.5 are also showing solid bars but in the dime/quarter/half range. If I get a quick audio hit and see this on the screen, I stop and investigate the signal further. If I can get a repeatable response I will pinpoint, and if a coin, it will normally show 2.5 dominant.

I normally stick with Best Data, but find that Correlate can be useful in areas with lots of deep rusty iron targets, as long as I take it slow with a recovery setting in the 85-95 range.

Thanks again,
Steve

 

[Explorer]

This brings up the question......The span limit is from 0 to 189 then OFF. In order to correctly set a span limit between the various frequencies you would have to know what each targets raw response for the three frequencies. So is there a chart showing the raw VDI responses of various targets at the three frequencies?

A VDI difference of 30 between the three frequencies is a lot of variance.

 

[Rob (IL)]

If it is too wide for you set it lower. The same for recovery or gain, if you don't like the default change it.