Find's Treasure Forums
Welcome to Find's Treasure Forums, Guests!
You are viewing this forums as a guest which limits you to read only status.
Only registered members may post stories, questions, classifieds, reply to other posts, contact other members using built in messaging and use many other features found on these forums.
Why not register and join us today? It's free! (We don't share your email addresses with anyone.) We keep email addresses of our users to protect them and others from bad people posting things they shouldn't.
Click here to register!
Need Support Help?
Cannot log in?, click here to have new password emailed to you
Changed email? Forgot to update your account with new email address? Need assistance with something else?, click here to go to Find's Support Form and fill out the form.
polar plot on spectra v3i
- Thread starter charliev
- Start date
I've tested them both. For shallow targets the polar will ID the different coins and ID foil and slaw pretty good. As depth increases the lines are not straight even on good targets. I think you will see that you get the same information with VDI numbers and pinpoint bars.
The other analysis screen (humps) might help you with size, but again you can do this in the pinpoint mode.
When both screens came out there were many posts on both. There was an attempt to distinguish gold, rings and tabs. You don't see many photos and posts any more. They are just another way of getting information, if you like them go for it. I encourage people to use what works for them. They just don't work for me.
The other analysis screen (humps) might help you with size, but again you can do this in the pinpoint mode.
When both screens came out there were many posts on both. There was an attempt to distinguish gold, rings and tabs. You don't see many photos and posts any more. They are just another way of getting information, if you like them go for it. I encourage people to use what works for them. They just don't work for me.
The polar plot is very useful for bottle-caps that are shallow (5 to 6 inches up depending on the ground. The vectors that are being shown are not the normalized vectors. Another way to think about this is for the unnormalized VDI numbers in polar plot form. Hence with the 22.5kHz the high conductive targets (quarter) will be shown toward the X axis as in unnormalized with a VDI of 90-91, while 7.5kHz will above this with the 22.5kHz line with a VDI of 83 and finally with 2.5kHz the line will be above both 22.kHz and the 7.5kHz line and the unormalized for the 2.5kHz should be around a VDI would 67.
Iron has a tendency to loop from the 2nd quadrant to the first quadrant as the electrical characteristics of a iron target may change as the coil is passed over it, hence the loops shown on the graph. and this is what I use the polar plot mostly for and I might only use this a couple times to help verify a bottle cap that is a little hard to tell from the signal strength of the 3 frequencies in pinpoint mode.
The plots are just a tool and as Rob said use what works for them.
rcsnake
Iron has a tendency to loop from the 2nd quadrant to the first quadrant as the electrical characteristics of a iron target may change as the coil is passed over it, hence the loops shown on the graph. and this is what I use the polar plot mostly for and I might only use this a couple times to help verify a bottle cap that is a little hard to tell from the signal strength of the 3 frequencies in pinpoint mode.
The plots are just a tool and as Rob said use what works for them.
rcsnake
CyberSage said:Hey Snake! Thanks for sharing the information. I guess for hunting rings this might be handy. I can see some value there. Too bad I am hooked on old coins.
Old coins are great to find and they can be deep. With the analysis screen, the weaker the signal is the less accurate they will be, especially with moderate to strong ground.
rcsnake
Neil in West Jersey
New member
The more I use the V3i, the more Polar Plot is growing on me. When I run with the RX gain up around 13, I find it to be fairly accurate, even on targets around 7 inches. I am easily able to tell if it is a coin, a button or a screw cap. Each has a distinctive pattern. Coins have straight (or slightly curved) lines, while buttons have two lines. Screw caps look screwy.
Here is a coin in single frequency:
Here is a button:
Sometimes in multi frequency it is more difficult to decipher but with a little practice you will learn to interpret it.
Here is a coin in single frequency:
Here is a button:
Sometimes in multi frequency it is more difficult to decipher but with a little practice you will learn to interpret it.
Neil,
Thank you for the attached pictures. My experience has been the same and at depths equal to what you indicated. Screwcaps are very easy to see in Polar plot. They are random semi-circular patters due to the iron content and will overlap in more than one quadrant. As you noted, coins are typically a very straight line in the positive VDI quadrant. Ground orientation will have some impact on how straight they are. slightly bent or even appear similar to your button display. Most of my good targets I measure up with Polar plot first before the final pinpoint and dig. The V3i's record up to the depths you mentioned is pretty accurate in the I.D..
Gotta love that V3i!
Thank you for the attached pictures. My experience has been the same and at depths equal to what you indicated. Screwcaps are very easy to see in Polar plot. They are random semi-circular patters due to the iron content and will overlap in more than one quadrant. As you noted, coins are typically a very straight line in the positive VDI quadrant. Ground orientation will have some impact on how straight they are. slightly bent or even appear similar to your button display. Most of my good targets I measure up with Polar plot first before the final pinpoint and dig. The V3i's record up to the depths you mentioned is pretty accurate in the I.D..
Gotta love that V3i!
Rob (IL) said:
They usually come off pretty easy once you break that little aluminum ring free at the bottom. Then I usually throw the aluminum screw caps in the trash. Then after I drink the wine out of the bottle I recycle it. Sometimes after a bottle or two they get harder to open, but for the most part I don't have problems with them.
I just tried out the Polar Plot. I swept the target,with polar in the main screen. I guessed what the target was before I dug. Most of the time I guessed correctly. The one target that fooled me was aluminum cans. The lines were straight. The spectro screen helped there, as the target showed quite large but with all three humps. I also noticed with aluminum cans, the depth is way off. It will show at 2 or 3 inches, yet the can was 6-8 inches down. One thing is for certain, the school kids in my area drink way to much soda on campus. 