Powerlines and the SD2000m

Hi All,
Great to be able to post on Ismaels great forum I would lke to pass on my experience with powerline interference and the modified (Barrie Johnson's Basic 4 selection) SD2000. I noticed this last Christmas while hunting in the \"AZO\" (Arizona Outback) area near Stanton, AZ.
I was hunting in the #4 (most sensitive) setting and using the CT 14\" Mono and doing quite well. However I was about 100 meters from a powerline that kept me from moving any closer for further nuggetshooting. My partner loaned me his NF 10x17 Mono after lunch and I went back to the closest point I could work before lunch with the other coil to continue. When I fired up my SD2000m I noticed there was NO interference now!!?? What happened? I'm still in #4. Well to make a long story not much longer, I discovered I could work in setting #3 as close as 7 meters from those dreaded powerlines \"Wow\" I was thrilled needless to say. There was a low rythmetic pulsing at that distance but it was something I could work with easily. I was recovering targets at 5\" or so and feel that I could have found targets deeper had they been large enough. I think of the posibilities if, I only had the extra mods that you offer Ismael Anyone else with a modified SD2000 have experiences they would like to share?? I'm all ears

George (Wishbone-NM)

G'day George (Wishbone)

After reading your post on Powerlines a light suddenly switched on in my memory bank of my trip to Victoria earlier in the year. I was detecting some diggings near a main road and I was running my GPM in Freq. 3 setting with my ML11\"DD and all was well until I decided to switch to Freq.4 for extra sens. over the many heaps I was scanning. My threshold suddenly went mad as if someone was closeby and a quick looksee in all directions I spotted a vehicle through the trees around 100 metres or more so put the interference down to its owner if detecting and if he was in range but out of my direct line of sight. Tried to persevere in Pos.4 but to no avail so switched back to Pos.3 and all quietened down and I continued on.

Some time later I happened to notice the said vehicle moving so I switched back into Pos.4 but the damn interference continued. Now my normal hunting ground has no powerlines nearby so powerline interference has never occurred to me until I read your posting and my experience on that day.

Now I am not certain if powerlines caused this interference but for some reason Pos.3 smoothed things out on my 2000 with ismael's mod also?

Lets hope others can throw in their thoughts on frequency positions and interference.

Thanks for posting.

G'Day GaryQ,
Thanks for your reply!! This is the only forum in the world that I know of that caters to the modified SD2000 user and your reply is a thrill
When I post something about the SD2000m and it's performance and characteristics, all I get is dead silence over here in the USA I guess my machine is considered a relic from the past but that's ok I also have the SD2100 but primarily hunt with my SD2000m because I'm much more comfortable with it. It discriminates hot rocks much better for me than the SD2100 and I like the \"low/high\" tone on a non-ferrous target (if it's big enough and close enough to the coil). Conversly it gives a \"high/low signal on ferrous targets as they're approached however sometimes that's not true so I'm always careful to identify the target. I've never found a machine with a discriminator that's perfect, close mind you, but never perfect
Montana Bob (Bob Dansie) , an expert nuggetshooter here in the states warned me about the low/high tone on none ferrous targets though. He said a large (3oz +) nugget will give a high/low signal so be careful and I am thanks to him Which modification do you have Gary and how do you feel about it for yourself??

George (Wishbone-NM)

George,

Your High/Low - Low/High tone findings with our beloved 2000's rang true with me also after I had read an old posting of your reply way back in March 2001 to a Discussion Forum under a heading \"SD2000 operating tips\" posted by \"Gary in Vegas\" At that time a mate who ran a GPX had a run with my 2000 and was amazed that the 2000 gave a Low/High tone over Gold which was opposite to his GPX that went with a High/Low over gold.

Another interesting posting I saved on file of yours was from the TreasureNet Forum, again way back in March 1999, under the heading \" Read this,SD2100 vs SD2000, Like apples to oranges!!!\" Here you mentioned burying a PVC pipe at 45 degree angle in ground for testing Detector and Coil combinations. Also you compiled results of tests between the 2000 and 2100 using Minelab 8\",11\"and 18\" coils in both mono and DDs punching through \"Dry\" and \"Damp\" soils. I caught the testing bug after reading through your findings and I am always getting stirred up by my other two detecting mates when out in the field and I decide to do a quick testing session.

With regards to my 2000 it was left to me by my Father after he passed away with the dreaded \"C\" word and just before I caught the Detecting Forum bug. Dad had \"Barrie Johnson\" do his \"Internal Sensitivity\" ONLY mod BUT without a 4 Freq. Switch change. He did offer this Internal Sens. mod with or without the 4 pos. switch. Also an \"Internal Audio Boost\" could be combined with either of the above and adjusted by a Knob on the back panel. The total cost at that time in early 2001 for all the mods was $240 but our mod only cost, I think, $98.

After reading about Ismael's GPM mod I decided due to lack of finances to upgrade to the GP range of Detectors, to have Ismael add his 2 \"Gain\" switches, 4 Pos.Freq.switch, adjustable \"Voltage regulator\" and \"Audio Amp\" to my slightly BJ modded 2000. Testing since IJ's mod against both mates 2200 and 3000 in- ground and air helped me big time to be confident I could reach their performance if I \"concentrated\" enough with the older machine like the 2000 being hotter up.

I only hunt with a ML11\"DD and a CT18\"DD to help quieten my threshold down especially running at max. voltage into the 2000 of 8.5 Volts and with both \"Gain' swtiches set to max. also. These settings sure can heat up \"Hot Ground' when \"Full On\" so different settings could offer advantages and disadvantages and can be a learning curve.

I am no expert as a Detectorists and would not class myself any where near someone like \"Pennyweight\" who has posted here about his haul of nuggets with Ismael's mod running Coiltek's DD Pro series and Monos. His knowledge and findings has been included in our Aussie GG&T magazine and is worth while reading. Hopefully his latest findings using a 2000GPM should be included in the Magazine soon.

Jonathan Porter our Aussie Prof. Detectorist gave an interesting report of his tests with a SD2000GPM on your \"AZO Forum\" back in March 17, 2004.


Post edited by: GaryQ, at: 2004/10/30 11:47<br><br>Post edited by: GaryQ, at: 2004/10/31 21:11

Hi Gary,
My heavens, just when I thought no one paid any attention to my posts on those tests way back when The information in your posts are most definately of interest and help to me also Gary. I'll copy your posts in reply to me and reread them from time to time. Your experiences with different settings and testing you've done is interesting AND helpful. That sort of thing gives me a heads up and food for thought with future tests I plan to do.
Sometime within the next few months I'll take the SD2000m (GPM2000), SD2100 and GP3000 and take a couple of days to bury the PVC tube you mentioned from my previous testing back in 1999. However this time I'll have a larger bore on the PVC for larger targets and this tube will be able to attain a depth of 24\&quot; (61cm) instead instead of 18\&quot; (46cm) as with the previous model. The smallest coil will be the CT Joey Monoloop and the largest will be the CT 12\&quot;x24\&quot;(30.5cmx61cm) Monoloop as the largest. A goodly variety of round and elliptical coils, both monoloop and DD will be in between the smallest and largest tested coils. Then I'll also attach the CT 12v-7.3v regulator on the SD's to see if it actually does improve depth on the tested coils and machines. Soil condition will be noted such as \&quot;wet or dry\&quot;. Unfortunately I wont have a wet soil condition report if the ground is dry or visa versa. That would be interesting too.This does take time as you know from your testing Gary. In addition there will be two people testing and each will check the other for accuracy in order to maintain an objective testing as possible.

Even so there will still be many varibles to consider as we all know but at least this will give us some idea of of what is happening with our detectors


George (Wishbone NM USA)

Howdy GaryQ,
Forgot to thank you for the reference to Jonathan Porter's article on March 17th, 2004 on the SD2000m as well as the heads up on more articles to be published on the SD2000m, by \&quot;Pennyweight\&quot;
I have a question for you since I don't have an instruction manual on the modified SD2000. When changing from one freq. setting to another. Is it advisable to turn the detector \&quot;off\&quot; and then change before powering the unit up again?? I've been changing it while the detector is on but always feel a little apprehensive about it I think Ismael has an instruction manual on the SD2000m but haven't figured out how to access it yet. Thanks for any info Gary.

George

George,

Glad to be able to offer you some help mate.

Jonathan's report on Ismael's mod. gave me some important hints when operating an older machine such as the 2000 or our hotted up versions. The three most important hints to me were to \&quot;learn what the detector is trying to say to you\&quot; , \&quot;perfect your swing technique\&quot; and \&quot;don't be afraid to experiment.\&quot;

Fingers crossed that Pennyweight's article makes it into GG&amp;T mag. and any hints he might be able to pass onto us old stagers with the 2000's.

Now mate, to your question on changing freq's from one position to another with IJ's mod without switching the detector off? I have had no problem performing this task when out in the field or doing a testing session. What you hear is a short type of high pitch duration of threshold as you change from Pos.1 to Pos.2 with a longer type of high pitch duration with Pos.3 and Pos.4 which sounds alarming the first time you hear it. Well it did for me anyway. It is fairly hard to explain the sound but as I recall the duration and level of its pitch seems not as pronounced when switching down from Pos.4 to Pos3, 2 and Pos.1 than when switching up. I suppose if you turn the threshold to minimum before switching it should reduce its pitch level and save your ears. I run a really low threshold anyway but still hear a fair dose of pitch level if switching.

When changing the \&quot;Gain\&quot; switch settings connected to GB1 and GB2 you get a high pitch growl as you turn to a higher postion towards its max. sensitivity. These gain settings really lift the receive signals of targets and from tests I have run, can add inches of depth.

I have found also that if you have been running the Voltage Regulator at its max. of 8.5volts and you switch off the detector, say at smoko or lunch time, you might have to turn the voltage setting back to a lower voltage before firing the detector up again.

Maybe Ismael can jump in here or start up under another heading on operating hints not already covered in his manual or correct me on my operating habits as I am here to learn and get the best from his GPM mod. on his Forum.

Hi Gary,
Thanks once again for your reply. Gary I don't have Ismael's mods yet but I'm seriously thinking about it I have Barrie Johnson's 4 freq. mod. However it's nice to hear from you on Ismael's mods. I currently use the Coiltek 12v-7.3v system but have done no testing with it to determine if in fact it does increase depth but I believe it does. Especially when you tell me you HAVE done testing and it does increase depth Thanks for that report Gary

I once had a Coiltek 1\&quot; (25.4mm) pinpointing coil with the switch and came to grief with that item attached to my machine. I was flipping the switch over to the pinpointer from the coil and let the \&quot;Magic Smoke\&quot; out of my detector. I wasn't turning the detector off first, as you're instructed to do in the Minelab Owners Manual when you're changing coils. In Coilteks' little instruction brochure they said nothing about turning the detector OFF before flipping the switch so I just assumed it was ok since I wasn't actually (manually) disconnecting a coil. \&quot;WRONG\&quot;!!! I sent the detector in for repair and it was saved! \&quot;Whew\&quot; that was close. Needless to say I'm kinda gun shy about flipping switches nowadays So thanks for your info on the freq. mod. switch and IJ's Gain switch settings

George

Hi Ismael,
Good to hear from you again!!! Yes I'd like to get your additional mods and look forward to that special pricing you mentioned. Where will you post the information once you have it ready for presentation?? I'll check back by dropping in on this forum from time to time. I'll need to talk with you a bit about shipping matters such as: Which is the best shipping carrier to use? What about \&quot;Customs\&quot; charges if there are any? Does shipping the unit and classifying it as a repair make a difference as far as \&quot;Customs\&quot; is concerned? What is the average turn-around time once you receive the unit in-house? there may be additional questions forthcoming OR additional information you have to offer in order to facilitate our transaction Hope to hear from you soon Ismael. I'll send you my personal email address by private messaging. Thanks

Wishbone (George in New Mexico, USA)