10.5" 7.5 khz coil

[rseasy1]

Just ordered my 7.5 khz. 10.5" coil from Richard at Backwoods detectors very nice to talk to and his deal could'nt be beat, look out silver and relics here I come you can't run and you can't hide I'm hopeing.
Now on with a simple question how much will the TID's change from the stock 9" concentric?

 

[chuckciao]

I have noticed that my penny signals range much higher (38-42) than with the stock coil. Quarter and dime (both silver and clad) signals are about the same. I think you will make it your go to coil.

 

[rseasy1]

Thanks chuckciao I was thinking about the three KHZ for the deeper silver or is there really much of a sacrife between the two coils my thoughts were with the MF coil that should cover desireable targets on both ends of the scale since Gold jewelery around here would be more of a streak of luck finding it but silver is more likely to be found with coins and all.
I understand Randys book about coils but I also GB around the low to mid 20's,So the DD might serve me better.

 

[chuckciao]

I also own the 9" 3khz coil and do find that it does seem to seek out deep silver very effectively but it comes only in concentric and I really like the DD coils. Also, the 10.5 covers more ground in large areas like parks which I prefer. Ideally, in a perfect world, Minelab would decide to make a 10.5 DD 3 kHz!!

 

[rseasy1]

Recieved my new 10.5" 7.5KHZ. DD coil from Backwoods detectors today installed it and tested it in my back yard,within a minute found a aluminum nail ,a zinc penny,and a copper penny all in the same hole.
Rang up a crisp clear 40. at about 6" deep.
Thanks Richard for such a great deal that no other place could match.

 

[Old Longhair]

You're going to love that coil!
It combines depth with separation and the most honest TID frequency range. Like chuckciao, I too would kill for a 10

 

[tjhoosier]

Bought my used 705 from Richard at Backwoods. Great deal and I couldn't be happier with it.

 

[rseasy1]

Went out with the 705 and my new 10.5" 7.5khz DD coil this morning. soil condition in the park was more sand than dirt started out with the following setup.
Sensitivity @ 24 , GB @ 15-3 to attemp more stable TID's. Noise cancelled @ 1Thresh hold set @ 7, Running in disc. 4 pattern. moisture in the ground was damp but not wet.This park is heavily trashy. I did manage to pull a few keepers but it seemed that mostly all the signals I was getting were very choppy I played with the setting a bit to try to smooth out the readings but just could'nt seem to get it right and did'nt seem I was getting very good depth.My deepest target I dug was only about 4 inches deep.My final setting ended up beingsensitivity @ 24 Noise cancell @ 2 Thresh hold@5 99 tones, Running in disc. pattern 2. I was still getting very choppy signals. The 1946 dime was only about two inches deep and rang in @ a choppy but solid 40 TID. What am I doing wrong to get the choppy signals? I used the auto ground balance after doing a reset in the park to get rid of the -3 on the GB.Also auto noise cancelle.Could it be the sandy soil? I had it out for a short time the day before at a local VFW and did'nt have this issue.
Very choppy signals and poor depth were my problems for the day. also the copper blob rang up a 34.
Thanks and any input and advice would be appreciated.

 

[BADBAJA]

Sounds like the same sand as around here. I am lucky to GB 6 on it, and if it's wet I use prospecting mode and dig just about everything. I think I ended up running 2 tones and notch off +48 and -9. Just make it a pattern and you can switch to AM real quick to catch all the TIDs. 2 tone really helps you pick the crud out and has fast response time. I run sensitivity 24-26 til chattering. The machine auto noise cancels and threshold is usually at 2-7 depending on outside noise. I know I might miss a couple things with notching but I usually scan anything with a +TID or solid tone multiple times. I am finding pull tabs at least 6in down and nickles at bout the same.

I know you wanted more accurate TIDs, but some conditions it might make it worse with a lower fq coil. Maybe try a comparison with a bucket and some sand from the area and the different coils or at the place your detecting. I always dig solid TONES as long as they are + numbers.

Prospecting is a whole different beast but I think if I got used to it I could mustly pull goodies(and tabs lol). The sounds might drive some nuts but the machine is "telling" you with just tones and you have to decipher and dig.

Good luck and keep us posted.

 

[Old Longhair]

OK, I have a few questions. Did you auto GB? Did you auto noise cancel? Or did you manually choose the settings?

What was the threshold tone doing? And why did you choose to have it where you did?

The -3 offset only works with tracking. Was your tracking on?

Target stabilization on?

The threshold tones might hold the key to what you might be doing wrong. Since you hunted in a DISC pattern, did you experience a lot of nulling? And if so, how quickly did it reset after each null? If there were lengthy periods of null, then there is a good possibility that you're swinging too fast. Switching to AM and trying to identify each tone will slow you down to a proper speed.
And FWIW, I usually hunt with my Threshold set on 1 or 2, just to be audible but not loud with the volume on MAX, using the controls on my headphones to actually manage the volume. But I must say that differences in headphones could account for differences in threshold setting needs.

 

[EOS]

Went out with the 705 and my new 10.5" 7.5khz DD coil this morning. soil condition in the park was more sand than dirt started out with the following setup.
Sensitivity @ 24 , GB @ 15-3 to attemp more stable TID's. Noise cancelled @ 1Thresh hold set @ 7, Running in disc. 4 pattern. moisture in the ground was damp but not wet.This park is heavily trashy. I did manage to pull a few keepers but it seemed that mostly all the signals I was getting were very choppy I played with the setting a bit to try to smooth out the readings but just could'nt seem to get it right and did'nt seem I was getting very good depth.My deepest target I dug was only about 4 inches deep.My final setting ended up beingsensitivity @ 24 Noise cancell @ 2 Thresh hold@5 99 tones, Running in disc. pattern 2. I was still getting very choppy signals. The 1946 dime was only about two inches deep and rang in @ a choppy but solid 40 TID. What am I doing wrong to get the choppy signals? I used the auto ground balance after doing a reset in the park to get rid of the -3 on the GB.Also auto noise cancelle.Could it be the sandy soil? I had it out for a short time the day before at a local VFW and did'nt have this issue.
Very choppy signals and poor depth were my problems for the day. also the copper blob rang up a 34.
Thanks and any input and advice would be appreciated.

You aint doing nothing wrong!
Xterra with discrimination gives choppy signals!! At least do mine and my brothers.Never use disc becuse of that.Even if the coin is just a few inches it still get an choppy signal..drives me crazy cus if Im in my permitted ground with lot of trash you really have to concentrate on the tones.I do all metal multitones,except sometimes in fields were I go 2 signal,cus I will dig anything that is not iron.

Xterra is a terrific detector but has what I think problem with discrimination and falsing,very sensitive to eletric cables.Now when there is cows in the pen I cant use my Xterra without falsing in my garden due to the eletric fence/wire.Well it dissapear turning sens down to 12-15,but then I dont get any depth what so ever.

But in the right condition the 10.5 MF is deep.

Last time out I found 4 coins from 1817,1803,1745,and the green one early 1700..
They were all found at maximum depth(around 10-12 inches),faint signal,but two ways 44-46.Pinpoint couldnt find it,and I had to sweep a little faster to pick up the signals.
I had the sensitivity at 29,ground balance 57 and noice channel 0.Treshold on 7.The ground was tough,very hard to dig but worth it.

3 silver were found in a row,and some newer coins.Not to much finds this time compared to last time.

Well this is just from my experience.

Mike

 

[rseasy1]

OK, I have a few questions. Did you auto GB? Did you auto noise cancel? Or did you manually choose the settings?

What was the threshold tone doing? And why did you choose to have it where you did?

The -3 offset only works with tracking. Was your tracking on?

Target stabilization on?

The threshold tones might hold the key to what you might be doing wrong. Since you hunted in a DISC pattern, did you experience a lot of nulling? And if so, how quickly did it reset after each null? If there were lengthy periods of null, then there is a good possibility that you're swinging too fast. Switching to AM and trying to identify each tone will slow you down to a proper speed.
And FWIW, I usually hunt with my Threshold set on 1 or 2, just to be audible but not loud with the volume on MAX, using the controls on my headphones to actually manage the volume. But I must say that differences in headphones could account for differences in threshold setting needs.

I always auto ground balance it set at 15 then set it at -3 as I seen in a post digger had done to help with a more accurate TID.
Also use auto noise cancel it set at 1.
By default threshold sets at 12 but I always lower it to a barely heard hum I use head phones so I can hear it well.It was set at 7 and later I set it at 5. I don't understand what you mean by what was the threshold doing?
I tried the tracking for awhile but it didn't make a difference so I turned it off as it my understanding the DD coils are more forgiving to ground balance.Also the same with the target stablization on and off
as it didn't seem to make a difference I didn't know the - or positive numbers on the G.B only worked with the tracking on .After all the different things I tried I still was not getting much depth and still very choppy signals.There was a couple times I would get someware around a 46 + or - reading at
10 inches or more but it always turned out to be iron pipes I located them and hit them with my magnet.
I'm going back to the place I was using the stock 9" coil in and run over the very same spot I hit before and see how it reacts at that location maybe it was just the sandy soil with
some wierd material mixed in with it.
How does one know when you have reached the optimal setting for a given site?
I still have alote to learn about getting this detector set up properly to use it to it's most effectivness.
Most of the time I use 99 tones should I go to 4 tones till learn to set it up better? I don't like to use disc. patterns no more than neccessary but sometimes I have to just to much info
for me to process in the headphones with out it.
Thanks for the help and any other info I can get as I'm still reading and learning about the 705 this last hunt with the new DD coil just tossed me for a lupe.

 

[Old Longhair]

Setting the GB Tracking Offset to -3 isn't exactly for more honest TID, but to make the machine respond as if the ground is a bit more mineralized than it is for stability.
The Threshold breaks whenever the coil passes over a metalic target. If the metalic object is one that is discriminated out, then it nulls, which is to say that the threshold tone breaks but does not produce a target tone. If the threshold tone nulls, and doesn't return to the threshold tone quickly, then there is the potential for missed good targets. It can be the result of many trash targets in the area hunted, the presence of patchy heavy mineral deposits, or a machine set to be too sensitive causing it to respond to slighter changes in mineralization.

There are sites that are nearly too aweful to detect. I've encountered a park where I think that they must have gotten their fill dirt from a foundry or something. Auto GB goes crazy at that place! And w/o Tracking on, you might as well save the batteries and stay home.

 

[rseasy1]

I'm learning more all the time ! I think there is something in ground in that park ware I had all the issues at.
I went back to a park ware I used the stock 9" coil and used the 10.5" DD coil there and it worked great did'nt have any great finds but
I just wanted to see how it performed there and it was great ran very smooth.
I just used the setting that were set by the detector.Here is what I had it set at!
Sensitivity @ 24 then went up to 27 after awhile and no chatter.
Auto noise canceled @ 0.
I manualy set the threshold at 4 does that sound good ? I could just hear the light hum.
volume was at 30 and adjusted with the controls on the headphones.
Auto ground balanced at 31 left it there.
Ran in Patter 4 for awhile then went to all metal and ran 99 tones all the time.
This all seemed to worked I pulled a few clad coins from around 4" - 6"s and pulled what looked like a brass lead weight from around 8"s deep.
Besides being able to run high sens. Is there other ways to adjust the detector to get more depth and maintain a decent TID.?
Thanks for the replies and the advice all this is starting to click as I knew it would.

 

[Old Longhair]

In a word...NO. Sensitivity IS essencially the depth control. Which is why those that are chasing deep targets tend to run their machines on the verge of instability.

It sounds like you're figuring it out. It takes practice.
Count on having a good 100hrs or so in on the machine before it clicks in your head. That's when it gets real fun!