What am I doing wrong with my SD2100??

[Lamar]

Dear group;

I guess that everyone should already know by now that I recently purchased an SD2100 from our very own prospecting professional and friend, Rob Allison! I bought this unit as a backup rig to compliment my GP3K in the hopes that it would be able to handle DD coils in hot ground better than my GP3K, but I am noticing that something entirely different is happening. It seems that the SD2100 works best with mono coils in hotter terrain than my GP3K does, but there seems to be no difference between the 2 detectors when I use DD Pro coils. What's up with this? I've heard that SD detectors typically prefer DD coils to monos, but I am experiencing the exact opposite. For instance I recently went into an area that I've not worked in before and I took both detectors along with me. I set up the GP3K with an 18" CTK mono and I couldn't get the threshold to smooth out. It was sort of like this, make a sweep or two then re-ground balance, over and over. I just couldn't seem to get it to settle down for me. So then I tried the same coil on my SD2100 and after the initical ground balance it seemed to hold the balance very well, with only minor adjustments needed every 15 minutes or so. It was also super-sensitive and the depth was impressive too. Then I tried the 17X11 Wallaby DD Pro on the GP3K on the same patch of ground and it produced the smoothest sweetest hum that I could ask for. Then I tried the same Wallaby coil on the SD2100 and it was a bear to ground balance in Channel 2. After I managed to get a smooth threshold, I didn't need to re-balance the unit any more, but I did notice that the loss of sensitivity and depth was quite noticeable in comparison to my GP3K. All of this is at odds to what I've been reading about the SD2100 series detector. Am I doing something wrong or am I doing something right? BTW, both detectors use the Coiltek speaker/amp combo and the Coiltek Pocket Rocket Lith-Ion battery system. The only other change that I've made to my GP3K is the addition of the Otto full fiberglass upper and lower shafts. The SD2100 retains it's original S bend shaft. I also route the coil lead wire to the unit control boxes in exactly the same manner for both detectors too. This is confounding me to no end!

Your friend;

LAMAR

[DOC]

The GP3000 was notorious for a drifting ground balance, until the machine warmed up. The first GP3000 I owned personally just happened to have a ground balance that never would get steady.

After repeated runs to Minelab they finally uncovered the problem and got it corrected, however it was always drifted for about the first 10 minutes until it warmed up.

Now the SD2100, that is a weird one. As a general rule the SD2100's are very easy to balance. Usually the DD's are always quieter.

So I really don't know what is going on with the SD2100, but you must be in some really hot ground. I have ran a SD2100 at Gold Basin all day long and never had to rebalance it, but 98% of the ground down there is really mild.

BCOT!

DOC

[Ted Scott]

I don't think you're doing anything wrong.

It's probably just the ground in that spot. In most cases, I've found that a DD coil on the 21 will be very smooth and it almost never needs to be ground balanced. However, I've also been in situations where a mono coil excelled and a DDPro would not run! Or at least it would run very badly. Go figure.

With any spot I'm detecting, I'd like to strike a balance between depth, sensitivity and detector runability.

That means, I'm going to use a mono coil whenever possible and a dd when I have to or as a cleanup tool. It seems to me that the best choice for that ground, given your options and description, would be the 2100 with a mono coil.

It's no big deal. You'll find spots where the GP runs better, spots you can't run the GP in at all, nugs missed with the SD or the GP, and the classic spot where you can't run a mono on the SD and have to switch to a DD. It doesn't seem possible but there are places where a dd won't run but a mono will excell. I have no idea why that is.

Good luck. I think you'll love your 2100 and find it a great additional tool to have. I'd never get rid of mine.

[Lamar]

Dear group;

Thanks for your replies everybody! And it's true that I haven't used the SD2100 in very many spots at all, only 2 different areas up till now, to be exact. The first area I didn't notice any differences at all between the GP3K and SD2100 and it seemed that both detectors handled both the DD Pro and mono coils equally well. The second area was where I was having problems at and I feel that I need to hit at least 4 or 5 more locations to arrive at any sort of intelligent conclusion. In the nextmweek I am going to be heading out to Camiri to give the GP3K and SD2100 a workout of sorts and try my luck at beeping some of that coarse gold that the area is famous for. I may get lucky and bag a nug or two if everything goes as planned, which will be a first, because nothing in my life seems to go as planned.

Your friend;

LAMAR

[nuggethunting]

Hello Lamar and All,

Well I have used all the SD's and GP's for a long time and this is what I know from my experiences. The SD's didn't perform well with the conventional DD's in my opinion. I always used a Mono coil on the SD's no matter where I was hunting. If the ground was too hot for a mono, I would just lift the coil off the ground about 1/2 - 1 inch. The normal DD's just didn't have the punch (depth) nor sensitivity like a Mono coil.

Now, the DD Pro's are a different story. They seem to work much better than the old DD's and even better if you're using a regulated battery system.

Now the GP's seem to do much better with the DD's and I believe it due to the added sensitivity of the unit over the SD's. Whenver I can I will use a Mono coil, but since the GP's are so sensitivity it's tough to run a Mono in certain highly mineralized areas. In these places I favor a DD Pro on the GP series.

If I can hunt with a Mono I will. There is no doubt a Mono gets more depth and senstivity over a DD and even a DD Pro. However, there are places where you can't use a Mono well, so you're limited to a DD or DD Pro coil.

P.S. All the SD2100 users also have the option to experiment around with the Channel 1 & 2 settings (rather than running in Search Mode). This gives the user many more options to play around with on extremely mineralized ground. Some SD2100 users are have good success using this combination (Channel 1, Large Mono Coil + Regulated Battery System pushing 7.5 - 8.0 volts to the Searchcoil). Do you smell smoke yet?

Hope this helps a bit,

Rob Allison

[Lotsa Luck]

P.S.  All the SD2100 users also have the option to experiment around with the Channel 1 & 2 settings (rather than running in Search Mode).  This gives the user many more options to play around with on extremely mineralized ground.  Some SD2100 users are have good success using this combination (Channel 1, Large Mono Coil + Regulated Battery System pushing 7.5 - 8.0 volts to the Searchcoil).    Do you smell smoke yet? 

<{POST_SNAPBACK}>

For me this is a MUST do!

[nuggethunting]

Hello Lotsa Luck,

The only problem when running the SD at such a high voltage is overheating. The added voltage is very hard on the electronics regardless of what anyone says. I think any SD user is pressing their luck running a unit at 8 volts. They are just asking for a detector failure, but maybe you will find that nugget that will pay for many detectors!

I think if you stay within 7.2 - 7.5 you're safe, but pushing it beyond that up to 8+ volts ....

Take care,

Rob Allison

[Lotsa Luck]

Hello Lotsa Luck,

  The only problem when running the SD at such a high voltage is overheating.  The added voltage is very hard on the electronics regardless of what anyone says.  I think any SD user is pressing their luck running a unit at 8 volts.  They are just asking for a detector failure, but maybe you will find that nugget that will pay for many detectors! 

I think if you stay within 7.2 - 7.5 you're safe, but pushing it beyond that up to 8+ volts .... 

Take care,

Rob Allison

<{POST_SNAPBACK}>

I was agreeing about the channel hunting with the 2100 not the extra high voltage. I almost always hunt in one or the other channels now since the ground I spend time on just hates the search mode. Its nice to have the option and thats probably why I couldnt stand the 3K I had.

[nuggethunting]

Hello Lotsa Luck,

I think SD2100 has a lot of options and can see why people love them. I know when I used the SD2100 I found pounds of gold and didn't complain a minute. Well, until the GP Extreme came out and then I knew what I really missed!

You still heading out this weekend?

Talk with you soon,

Rob Allison

[Lotsa Luck]

You still heading out this weekend? 

<{POST_SNAPBACK}>

Yes, I have a mine to locate...

[Lamar]

Dear Rob;

I love that Coiltek Pocket Rocket lith-ion battery! For me, 7.3 VDC is plenty of juice and I'd be afraid of cranking up the voltage higher than that. I also feel that the Pocket Rocket and the Coiltek speaker/amp, when used together with an SD2100 really levels out the playing field when comparing the SD2100 to the GP3000. On my GP3K the Pocket Rocket and the speaker/amp are very convienent to have BUT I don't feel that they have actually boosted my detectors' performance level but on my SD2100, that is an entirely different story. The GP3K is still my primary detector, but when the ground starts to get variable enough to have to switch into TRACKING that is when it's time to fire up the SD2100. On mild to moderate terrain the GP3K comes out the winner, but when the going gets tough, the tough get SD2100s!

Your friend;

LAMAR