Pinpointing Help please

[nbforrest1863]

i have the 10.5in 7.5hz DD coil and use it for relic hunting. it is amazing. the only trouble i am having is the pinpointing part. i find more times than not, i am digging a few inches off from the target. does anyone have any advice they can offer up on this subject? thanks!

 

[Mick in Dubbo]

Hi nbforrest.
There are a couple of ways that you can pinpoint with the round DD coil.
You can go into pinpoint mode and after centring the coil over the target, wiggle the coil from side to side with very short movements as you slide it back toward yourself. When you loose the signal, the target will be right under the front edge. Really shallow targets sound the loudest, right under the Minelab logo as well.
You can also pinpoint, by passing the coil the coil over the target paying close attention to the spot where you hear the target, then turn through 90 degrees and pass the coil over the same spot. The intersection of where you hear the sound, is the location of the target.(X marks the spot.)
An important tip to remember while using any pinpointing technique, is to pay close attention to your depth metre. Sometimes, when you think that you have a target centred, you have picked it up with the side of the coil both times. When the depth metre is showing you, the shallowest reading, that is when you know that you have centred the target correctly.
Mick Evans.

 

[mcseeker]

Someone told that the pinpointing is more accurate in prospecting mode.

 

[nbforrest1863]

thanks mick!

 

[sport.pilot]

Mick,

Good post. Does that depth meter info apply to the standard 7.5 KHz coil as well. I am doing better pinpointing with it, but am still having trouble putting the target in the center of the coil's circle. Even by raising the coils up fairly high at times in the pinpoint mode, I still find that the bars of the inner circle light up before the sound gets to its highest pitch. When Xing a target, I am having some difficulty putting the target in the center. However, I have not been paying much attention to the depth meter. I have no problem with centering the coin under my small 6 inch coil. I have had some luck with pinpointing with my 5X10 coil, but have not really practiced much with it as of yet. I am really starting to enjoy the detector. Yesterday, I was able to recover 10 coins with the standard coil, 6 dimes, a quarter, a 5 cent piece, and two 1970 pennies. That is by far the best I have done. I guess like anything else, the more you do it, the better you get.

 

[BarnacleBill]

The pinpointing mode is an auto-tune type. The more times you swing over the target it will turn down the sensitivity automatically with each pass of the coil over the target. Try it by throwing a coin down flat in a target free area with a wooden or plastic ruler centered on the coin. Swing back & forth smoothly while noting how the detection field collapses in size with each swing. After a few swings there will be a very small hot spot.

[attachment 90740 ruler.jpg]

HH
BarnacleBill

 

[Mick in Dubbo]

Are you sure about that Bill. If you are right, then I've had 2 control boxes in a row that are faulty. Mine doesn't do that. It has pretty much always been a very sloppy pinpoint, which would go a very long way to explaining why I seem to keep coming to grief with the standard coil.
Sport pilot.
With any coil, if you have a target that is not properly centred, then both the target ID will be off as well as the depth metre showing the target being deeper than it actually is. Once you have a steady reading, showing the shallowest reading, then you can be pretty sure that you have the target centred. If the depth metre is jumping all over the place, then it's a good indicator of a junk item; just like as if the ID reading was jumping all over the place. If the depth metre is jumping between 2 specific depths, then you probably have 2 seperate targets under the coil. This applies to any detector. I use the 30, so once the pinpoint mode is engaged, then I don't get depth readings any more.Just the last reading prior the the pinpoint button being pressed. I believe that the 70 will still give read outs while in pinpoint.

Mick Evans.

 

[BarnacleBill]

Yep that's how it works. You can check proper functioning by throwing down a coin in a target free area.

Then off to side over clear ground with a moviing coil one inch above ground, engage the pinpoint. Lift coil six inches off of the ground and move over top of the coin. Swing coil left<>right as you lower the coil to one inch above the coin. Make at least three swings at one inch over the coin, then quickly raise coil to six inches above coin and continue swinging coil. When the coil reaches six inches the signal from the coin will have disappeared. Continue swinging coil at six inches and the detector will gradually increase it's sensitivity till you can once again hear the coin. This is the auto-tune sensitivity at work.

HH
BarnacleBill

 

[Mick in Dubbo]

Thanks for that Bill.
Little wonder, I've been tearing my hair out with it at times. After sending it back twice, and being replaced on the third time, that should make 3 unfortunate events. that puts me on track to getting it right on the forth time. When my finds accumulate enough, the 30 can be used as a trade in on the 70.I have no confidence that a repair will be properly effected, so I'm not sending it back again. In the mean time, I'll stay right away from the standard coil.
Mick Evans.

 

[sport.pilot]

Worked perfect for me Bill, just exactly like you said it would. Thank you again for ending hours of frustration!