Question on the spectragraph in practical use

[TabWhisperer]

First I do not own a V3i or VX3. I had a V3i several years ago when they were relatively new. Tonight I was poking around to see what might be new. Then I got into watching several videos on them to get a little familiar again. Now I'm wondering what practical purpose the frequency bars serve when the responses were just reflecting the displayed VDI? It seemed redundant (still cool). A 19 VDI resulted in the blue bar being strongest and an 84 reflected in the green bar the strongest, etc. I never saw any variation from that theme. I wondered if are there situations where that may not be true and the graph provides additional details to the operator? For instance there may be a 84 VDI displayed but some other frequency comes in stronger than the usual green bar. What would that mean to the operator as far as target analysis goes? Does it help ID possible iron targets next to good targets?

 

[shelton7522]

Plenty of information. Higher freq. bar domination - probably foil or alloy trash. Red bar with green on lower freq. means rusty iron. Try to work in stereo mixed mode. This is additional information in static channel and more precise bars with segments.You can watch bars spread or growing in time.

In pinpoint mode bar length describe kind of material and size. Use polar plot and read users manual in pdf. You have many information here.

 

[Scott (Mid-Mich)]

I've been watching a few V3i videos on Youtube over the last few days, and I saw one that relates to your question. The guy hunting showed his machine getting a good sound and hitting at 85 VDI, but with the red bar being the largest. He said he knew it would not be a coin (quarter if I remember correctly) as a coin would show the green bar being larger. He mentioned that whenever the VDI and sound were good, but with the red bar being the biggest, then it would be a bottle top or some similar junk and not a coin. I have found this to be true in my experience using the V3i also.

In my mind if the largest bar is green, then that means dig, and if red, that doesn't necessarily mean not to dig, but to stop and think about it. With me, I have not had much luck with targets where the sound/VDI were good and the larger bar was red. Now I tend to bypass them. I think the best way to learn is to pretty much dig everything with a good sound and VDI, and then see what it is with a larger green bar compared to a blue or red bar.

 

[TabWhisperer]

Thanks. In the time I had my V3I I never saw that happen with a high VDI and a red or blue bar dominant.. Like I said it's been several years. Seeing the typical YT stuff just reinforced my experiences and had me wondering about it.

 

[gabbyhayes]

Just another tool in the chest. It helps you determine if you have a good target or junk. Its value diminishes somewhat as the target gets deeper.
Having said that, it is very accurate on shallow targets. The polar plot or the camel humps all help paint the picture. If you are hunting at the beach in sand it is usually quicker to dig.
I don't spend too much time over analyzing. Rings often appear as junk so if you want to find rings you have to dig more junk.

 

[Wayfarer]

Just to clarify, we're talking the horizontal pinpoint bars not the spectragraph. Isn't the spectragraph on the regular search screen with the little vertical bars fr each frequency that correspond with the VDI number? I use the spectragraph to see how consistent the target VDI is, especially for a medium to shallow target. If it "smears" then it's usually iron or junk, regardless of the VDI number. A night tight vertical bar, especially when they all line up from the different frequencies, generally indicates a good target. As gabby points out, the accuracy and usefulness drops off as you start to look at deep targets.

Now if we are talking pinpoint bars, my rule of thumb is low conductors should hit hardest on 22.5 (blue), mid conductors on 7.5 (red), and high conductors on 2.5 (green). If there is an inconsistency, say for example a low conductor hitting on green the hardest (usually iron), or a high conductor on red (like bottlecaps)., then it means the target is likely junk.

 

[MackDog]

Well you never know. Tokens and Indian Head Penny's, wheat's will also show with red dominant as well as zincolns. Good rule is if it sounds good and is deeper than 6" dig it you'll be surprised. Picking up highly corroded V and Shield nickels that are all over the board with vdi'Ss but blue dominant. Hope this helps MackDog