Need help with X-terra 70 in trashy areas

[Clad 2 Meet U]

Yesterday a went to a very trashy area with my x-terra 70. I became very frustrated and was wondering how you folks handled these types of situations. I'll start with my settings. I manually ground balanced the machine, was using a threshold of 3, sensitivity of 22, stock coil, headphones and bounced between coin mode and all metal. In coin mode I know I was missing the coins that were mixed with the trash so I thought all metal was the way to go. There was so much trash at this park that the machine was going crazy with the VDI numbers and If I did get a VDI that was what I thought was a coin signal, I would have to really try to feather the sweep of the coil to squeeze in between the trash. 9.99 times out of 10 I dug garbage. This park dates back to the early 1800's and has been known to give up some nice seated coins. I only managed a few bucks in modern coins and a '48 wheat for an all day effort.

Is there something I'm failing to do other then buying the 6" coil or is there some tricks of the trade that you folks are willing to share because I'm about ready to pack this machine up and sell it. My friends seem to do better with the explorer's on target separation then what I'm able to accomplish with the 70.

Help!

 

[Jackpine Savage]

Also what is the typical depth of the older coins those Explorer guys are getting. Forget the VDI if you are using tones and go by the repeatability of the signal.

You may have to lower your sens and you can also try running the threshold down to 0. At lower sensitivity settings (19 or below) the 70 is not as susceptible to signalling on deeper iron or targets near the edge of the coil which helps a bunch with the stock coil. Go slow and overlap your sweeps to the point that you are using the open center of the coil as if its a small coil on the end of the rod.

Tom

 

[Clad 2 Meet U]

Hey Tom! Thanks for the reply. Mostly modern trash... The coins range from 4 to 8" in depth for the oldies, the newer are 4" and up it seems. I know the 70 can reach those depths from past experiences. I tried both 4 and 99 tones, what do you recommend for that? I thought if you lowered your sensitivity you lose depth, am I wrong on this assumption? I'll try the threshold @ zero next time out. The iron, pulltabs, bottle top and shredded aluminum is everywhere. One sweep of the coil in all metal mode reveals at least 10 different VDI's and tones. This park is one tough bugger to detect!

 

[khouse]

Just like anything else. You need the right tool for the job. In your case it would be a 6 inch dd coil. You've done about all you can with what you have and environment. This is exactly why small coils are made.

 

[Jackpine Savage]

I'd suggest switching coils to have chance against those Explorer guys. The stock coil does have its limitations in those conditions. If lowering the sens to the 16-19 range doesn't do it, give the 6" DD a try and that doesn't get down deep enough consider the 10.5" DD 7.5 khz.

First though try the stock coil with lower sensitivity. Experiment a bit, try tracking on and also use a trick some of us learned about switching to Beach GB mode when using lower sens settings. It will usually gain back some depth when using a slower sweep.

Tom

 

[BarnacleBill]

I know I'm a bit of a cheerleader for the 6 inch DD 18.75KHz, but it's honestly like throwing a light switch. For raw depth you will probably not compete with the Explorers with the six inch DD. But getting down into the 7 inch range should be achievable, and where you will really compete is in unmasking targets adjacent to trash. If with the stock coil you are seeing what you think is 10 targets per swing, with the six inch DD it may reveal 30 to 40 targets in that same swing. If you decide to get one, my number one mantra is SLOW DOWN with it, otherwise targets will go whizzing by and your ears won't be able to keep up.

HH
BarnacleBill

 

[khouse]

Yes the 6 inch dd coil will sound like a machine gun if swept fast over a lot of trash. Best little coil I've ever used.

 

[Clad 2 Meet U]

Well thanks guys! You have giving me the inspiration and some added knowledge to keep plugging away at it with my 70. I don't have the 6" DD but I do have the 10.5" 7.5khz. I have the 6 x 9 coil also. Been thinking about selling the 6 x 9 and using the proceeds to put a dent in the price of a new 6". I pulled the 10.5 before the hunt thinking that using the 9" would be a better fit with all the trash and because I have a heck of a time pinpointing with the 10.5". I will print this topic out and keep it handy for the next time out to the park. So you recommend the 18.75khz 6" instead of the lower frequencies... Why is that?

 

[khouse]

I bought the 6 in hf dd coil just in case I ever go prospecting. It turned out to be a great coin coil too. I would say the 6 in mf dd coil would be fine also. You might raise your stock coil above the ground a few inches for a little better separation too.

 

[xwyokid]

From my personal experience the guys are right you probably would do well with the 6" coil. My first lesson with this coil was, whoa horse, slooooow down. Personally I think smaller coils make us better detectorist because of the small amount of ground the coil covers thus forcing us to slow down and listen closer.

 

[Tom G]

The main difference between the 6" 18.75 kHz coil and the 6" 7.5 kHz coil, other than the obvious frequency difference, is the way the coils are wound. The 7.5 kHz coil is a concentric and has a cone type pattern whereas the 18.75 kHz is a DD and has a blade like pattern down the center of the coil. Being a much narrower pattern there are fewer targets under the "hot spot" of the coil at a given time. This of course increases your ability to distinguish between targets that are physically close to each other especially if you keep your coil speed reduced somewhat.

It would be nice if there were a 6" 7.5 kHz DD coil as that would most likely be a better choice for your situation but I don't think using the higher frequency would make that big of a difference in searching for coins.

You mentioned that you have the "6 x 9" coil. I think you are probably referring to the 5" x 10" elliptical 18.75 kHz DD coil. If so you are in luck. This coil is also a DD design with the narrow pattern and it is 1 inch narrower than the 6" DD coil. I have used both these coils in high trash areas and I prefer the 6" but the elliptical is not that far behind. It is certainly much better for target separation than the 9" stock coil that you have been using.

If I were you I would give the elliptical coil a try. If your VDI numbers are still going crazy and you are still digging junk at a rate of 9.99 out of 10, I would suspect that your problem involves something other than coil selection. If the situation is noticeably improved then you can choose to continue using the elliptical coil or to invest in the 6" coil.

In my opinion, there is enough of a difference between the 2 coils to justify going to the 6" coil for the type of hunting that you want to do, but for my own uses with the X-terra 70, I can't do without either of these coils, so you might hold off on selling your elliptical until you give it a good test.

Tom G

 

[Clad 2 Meet U]

Thanks Tom! You are correct... 5" x 10" elliptical 18.75 kHz DD coil. Next time I head out that way I'll pop that bad boy on and give her a try.

Kind Regards to all,

Greg (C2MU)

 

[Steve missouri]

Greg: Look and read page 30 & 31 of the X-terra 70 manual, I'm supprised that you found any coins clad or other wise, with a sensativity setting of 22 in a trashy park. The setting should have been between 8-10. The siginal that goes in the ground is set by the Detector, and is always the same, the sensativity is an amplifier that amplifies the return signal from the ground. In a trashy area the amplification at 22 on the X-Terra will overwhelm your ability to pick out individual targets. I also agree that the 6 inch DD coil will help a lot,

 

[cosmic]

Look for repeatable signals and vdi that doesn't vary more than two ..(36-3