Coil Performance Differences

[synthnut]

I'm seeing a 5 x 8 DD coil and a 6.5 x 9 Concentric coils in the Garrett lineup .....I was wondering if anyone has used both and can comment on the differences between the two ? ....... Or give me the rundown on either coil if you have purchased one and give me the skinny on your coil ....THanks, Jim

 

[goodmore]

The 5 x 8 is a hot little coil. I used it for the first time yesterday. We hunted a wooded picnic area. Alot of leaves on the ground. The 5 x 8 had no trouble getting into the dirt. Targets were not deep. But the pinpointing is real real easy. Target seperation is probably about as good as you are going to get with any detector. Lets face it. The stock AT Pro does a very good job. This coil has a much smaller footprint. This coil is definately not as deep as the stock coil. But when you look at the size difference you could have pretty much guessed that. It is deeper than the the little sniper hockey puck though. It might just be the best small coil I ever used. It was fun. I am looking forward to getting back out there with it. Target ID remained very good too. Sometimes a smaller coil throws the target ID off on detectors.

 

[blade310]

Hi synthnut. I have only had the 6.5x9 in'' concentric coil on my Atpro. I had the stock coil on just long enough to test it for falsing. I have never tried to get any depth. I basically was a clad hunter all season. its an exellant coil for clad hunting. I also found 5 gold rings and 6 silver rings with it. I may put the stock coil on it next year. (would be like a whole new machine to me)

 

[seahunter34]

My ATPro with the stock DD coil is 1 Hot machine! It hits targets/coins deep and covers my difficult ground much better than any mono! To me the newer Garrett 8.5X11 DD coil is the best DD coil I've ever used and I like it so much, I'll get the 5X8 DD for it too!

 

[Vinnie]

Got the 5x8 yesterday and with the little testing I've done I know it will hit coins in iron infested spots that the stock coil just goes over without a peep. Air testing it gets about 1.5 to 2 inches less on coins (1 on nickles, 1.5 on quarters). Looking forward to getting out to parks soon.

 

[GoGoGopher]

I like the 8.5x11s abillity to pick coins and jewelry out of trash, so I would think the 8x5 would do an even better job with it's tighter pattern...My question is this...
The strip down the center of the coil is still about 1" wide, just 3" shorter...But the width of the coil is also 3 1/2" less, thereby putting more of the signal into that 1" strip...
Do I have this theory correct? would the signal reception actually be stronger, but just not as deep???


Thanks,

 

[EtracTom-AdirondacksNY]

All I know is it's a great coil I got one and at first thought boy it's quite a bit smaller then the 11" coil but it's hot and seperates unbelieveably well and goes almost as deep and made the machine feel really light now easy to swing all day.

 

[synthnut]

Thanks for the input guys .......I'm in some pretty intense trash in some NYC parks , and the larger coil is a great coil but see's too much trash all at once and sounds off on ALL of it ......I'm looking for a coil to pretty much seperate and pick thru the trash a little easier ....Not sure which of these 2 coils ( concentric or DD ) would be better suited for this situation .....I'm thinking maybe the DD would be better ....???......THanks again, Jim

 

[Vinnie]

Got out to a real trashy park yesterday where I've used the larger coil many times. The little guy was finding stuff I had missed. It's worth mentioning that it's much better at ID ing Al screw caps, they used to drive me nuts but now theres a distinctive scratchy sound to go with that 81 to 86 VDI, saving me lots of digging trash.

 

[EtracTom-AdirondacksNY]

Synth the DD will seperate better as the signal is only the small strip down the middle of the coil about 1" wide BUT 8.5" long (5.5x8.5 newer coil) from the tip to the tail of the coil AND it goes down into the ground in a U shape so goes fairly deep as well so you don't have to overlap your sweeps only a little bit like maybe 25% or less.

On concentric coils the pattern is like an upside down icecream cone as wide as the coil is at the top but tapers down to almost a point at the furthest point the signal reaches so at depth your only getting a very, very small signal so you will have to overlap a lot of your last sweep at least 50% or more of each swing so as not to miss anything at depth. That is the real difference.

I always prefer a DD coil it's best of both world,s seperation and depth PLUS it sees less of the ground mineralization so ID's targets good at depth too.

 

[Sailorman]

I haven't used the concentric coil but have used the 5 x 8 DD in some heavy trash that defeated the large coil and found good targets with it. You just have to go slower and really listen but it will do a good job.

I contacted a tech at Garrett and asked if the concentric would perform well in heavy trash and he said no. The concentric would give better target resolution and more reliable ID but only in a low trash and low mineralization environment. Since I seem to hunt mostly in high trash I went with one of the first of the little 5 x 8 coils and haven't regretted it!

 

[synthnut]

Thanks again guys ..... I have to go really slow anyway ......I don't havea choice ....There is enoough trash in these parks that you could virtually spend all morning checking a 10 ft x 10 ft area !!...... I'm not kidding ...... This is what it's so important to check the area with a small coil and move SLOWLY !!......

Vinnie ,
Thanks for that info on the Screw caps .....Those older Wine bottle screw caps are one of the only pieces of trash that still fools my E Trac !.....They sound as sweet as Silver and in these parks they are down a good 7-8 inches !!...... You dig that hard ground thinking SILVER the entire time , and when you get to that screw cap it takes the wind out of your sails quickly !!.....Jim