This has probably been asked but here goes!

[88junior]

On the X terra 505 at what ground balance numbers should I consider switching from a concentric to a DD coil? My ground balance numbers on the concentric is usually 20-22 and is around the same using the 10.5 DD 7.5 kHz coil I've read the concentric is deeper but I am not sure which I should use with these ground balance numbers.

 

[Mark in S.E. IA]

With GB numbers in the lower 20's I would use the DD coil and when you have GB numbers in the very upper 20's and higher I would use the Concentric coil.

 

[atomicscott]

I believe (remembering from Randy's ebook) on the XT 505 a GB phase of 15 or less would be an advantage to use the DD coil, a GB of 28 or less for the XT 705. It would be 30% +2 of the total ground balance range.

 

[morelic55]

Bought new, the stock 9" coil is left in the box. I just like the 10.5 DD coils better, no matter what the ground is. I know that the stock 9" coil will not hit the .69 cal bullet I have at 12" in my yard, but the 10.5's...Both of them will. I always hunt in tracking mode on the 70/705's also and get super depth without a tracking off set also!!!..............Mark

 

[Canewrap]

+1 Mark. I too have a couple of planted targets in my yard and my 70 with the 10.5" MF DD coil is the only detector I've used that will hit a small flat button (slightly smaller than a dime) at 8" and a bullet at 10". I also have a couple nails near the bullet and I can still get a high tone on the bullet. I'm convinced my 70 was well tuned to begin with (or hot as some would say) because the 705 I used to have, just wouldn't get the same depth on these very same targets. I've always used a Tesoro for relic hunting in the past, and relegated my X-terra to coin hunting, but I'm rethinking that and will devote all of tomorrow to use my 70 to hunt for a CW camp up in Tennessee. When hunting for a new camp I'm always afraid I'll walk right over it because the detector is just not getting enough depth.

 

[Old Longhair]

When hunting for a new camp I'm always afraid I'll walk right over it because the detector is just not getting enough depth.

Have you ever tried Prospector Mode at sites like that? It runs deeper, yet doesn't disc out non-ferrous metal, so lead, gold, pewter, and the like will stand out.

 

[mapper65]

Bought new, the stock 9" coil is left in the box. I just like the 10.5 DD coils better, no matter what the ground is. I always hunt in tracking mode on the 70/705's also and get super depth without a tracking off set also!!!..............Mark

Agreed!!!

 

[Canewrap]

Yes, I'm familiar with it. This mode is best used after you find a site worth hunting though. Because of how much ground there is to cover when relic hunting you will waste a lot of time digging everything if you start in this mode. I used to hunt with a guy that had an X-terra 70 before I had mine and he used the prospecting mode to find deep targets on pounded sites. Now, if I had any pounded sites to hunt it would be first thing I would try, but it really requires a lot of patience if you're hunting in an iron-laden homesite or campsite.

 

[Neil]

With GB numbers in the lower 20's I would use the DD coil and when you have GB numbers in the very upper 20's and higher I would use the Concentric coil.

I didn't know this. I hunted a drained lake today, mostly a gray/yellow clay bottom, ground balanced at 2 and 4 depending on where I was. I had the 10.5 med freq coil on. Dug some foil and a few coins but what a pain, clay sticks and holds tight to the scoop, and Im out of "digging shape" as Ive not hunted a whole lot this winter.
Thankfully the weather has warmed alittle, this lake bottom was frozen good a week ago.

 

[Canewrap]

Well, I never gave my X-terra a fair shake as a relic hunter and now I'm sorry I didn't sooner. While searching for a CW camp over the weekend did find an old homesite and it was getting the depth I needed as well as being able to hear non-ferrous in among the nails. Had to slow down a bit to distinguish the non-ferrous, but it's worth it. The big change that allowed me to consider it as a relic machine was replacing the S curve shaft with a straight shaft. This allowed a much more comfortable balance while using the 10.5 MF DD coil. This coil and tracking were key to searching this site as I noticed the gb really varied over a short distance and because a lot of the mid-range priced detectors sold today really don't have a reliable method, that I know of, for telling when the ground balance is changing so drastically over a real short distance and let you know you need to rebalance. Frequently re-balancing with a manual machine is one way, but all it takes is a short distance to walk over the find of a lifetime. Didn't find any coins, but we were recovering targets down to half the size of a dime at about 8", so will be going back to see if we can pull any coins out of this site, in addition to trying to locate the CW camp we know was in the neighborhood. Did I say I really like my X-terra 70.