Whites TDI Classroom

Welcome! Log In Register
New TDI SL user and a couple of questions
Posted by: Bill W.
Date: November 10, 2017 04:32PM
I just recently bought a TDI SL with the 12" dual field on. I only have about 2 hours of hunting with it. I've already dug my share of nails. I was wondering if the audio is different with iron. I dug a few nails that sounded on the smoother side in tone. In air tests, I can tell it's iron... in the ground ... not so much. On the back of my SL there's chart that says use 7 for ground balance. If I use a ground balance of 4 like most say to use I don't get any audio from low hitting IHPs. I do get audio on the IHP when I use a ground balance of 6 or so. These are really low hitting IHPs but they aren't 'fatty's'. Also, how much does my ground dictate the 4 in ground balance? Meaning, if I ground balance at 8, should the ground balance number for the coin setup change if I ground balance at 9? I hope you follow what I'm saying.

As I push the pulse delay up, it decreases sensitivity to lower/smaller conductors. Higher pulse delay number are also poorer at iron rejection. Is this right?

I was also wondering how badly the SL suffers from masking due to trash. Knowing this will help me pick a coil for the parks I hunt during the summer. I hunt a lot of farm fields in fall and spring that previously had schools, churches or homes on. During the summer I hunt parks more. I was looking at the Nugget Finder 6 x 8 'Sadie' coil for park hunting and heavier trash areas. I've seen some good reviews on it and I'm leaning towards it. I also was looking at the Miner John 6" folded mono which might be a better size. I've also looked at a Detech 11 x 6 mono but I think that's too big for a trashy site. I am not a newbie to detecting. I've been doing if for 17 years or so. Although, I am new to pulse detectors. I currently own an Minelab Explorer, Makro Racer and XP Deus. They all excel at different aspects of detecting. I've owned quite a few detectors over the years. I want to learn the SL as best as I can while I'm field hunting. It's much easier to dig holes. :) I have a few sites that signals are deep I'm looking forward to see how the SL does. I live in Western Pennsylvania and the coal cinders are a real pain at some of my sites.


Re: New TDI SL user and a couple of questions
Posted by: markg
Date: November 18, 2017 07:33AM
You are correct in that increasing the delay doesn't help eliminate nails but actually enhances them. The SL is not for the faint hearted hunters. I might help you with the audio question though.

When I first got my TDI, the very first target I dug was a mercury dime from, what I believed to be a completely hunted out site. Then for the next 2 hours I dug nail after nail, I had actually started thinking, ops maybe I should not have bought the machine after all. Now fast forward 4 years and my attitude has changed.

Story is in order:

Years ago I met hunter (since has passed away from cancer) using a cheap bounty hunter machine. We started hunting together once a week and it was amazing what he was finding over me. At that time I was using one of the best VLF machines, not mention the name. This particular day I was hunting about anything that would give a good repeatable audio. He as usual was whipping by butt with very little effort on his part and to make things worse was hunting behind me 20 or so feet. I had dug several nails and a few coins and absolutely no jewelry. Then David yelled and motioned for me to come back to him. In his hand was a very nice gold ring found in my actual foot steps some 20 feet back. I was sure there was no way I had missed that target because I was digging just about everything. Then he ask, how I was coming with the nail problem in the area. Feeling a little ashamed I reached into my pouch and pulled out a handful of different size nails and trash from the days hunt. Then he broke the news saying, I never dig nails. I ask, how he could possible not dig nails in this particular area. Audio, my friend, I can tell the difference, it's easy. Well for the next several minutes we hunted nails and sure enough he knew by the audio and my machine would indicate both a mixed audio and an ID that could be a coin. But there was a lesson to be learnt from the humbling experience with my hunting friend. He had hunted with this poor old, beat up, cheap detector for some 15 years. Being an educator I realized, years of hunting with the same machine had in a sense programmed his ears/brain to the audio report from the detector. As a final not he drove home the lesson by allowing me to listen to his detector over a nail and then over a coin and I can actually say there was no difference, they all sounded the same.
Now back to you and the SL, take your time and listen carefully to the audio you get.
I can assure you if you spend the time, the audio will start to register and you'll have a good idea about the nails before digging.
Try to concentrate on what you hear.
Rotate around the target, does the audio length change, longer audio in one direction might indicate a nail.
Raise the coil as you sweep, if the target suddenly goes away it could be a nail.
Most important, don't give up, mix it up, hunt coins one day then the next time hunt only gold.

Re: New TDI SL user and a couple of questions
Posted by: Jim in Idaho
Date: November 18, 2017 08:57AM
Here's a GB chart for the SL. Where the vertical, dotted GB line intersects the various target lines indicates the tone you'll hear. The chart helped me figure out the GB.

Re: New TDI SL user and a couple of questions
Posted by: Bill W.
Date: November 19, 2017 11:30AM
Thanks for the replies. I have been able to spend more time hunting with the SL. In ways it reminds me of my Explorer. My Explorer will false on iron but if you pay attention the audio is rough when it's iron. Tomorrow I'll be using the SL again on a field. It's another tool in the arsenal... :)


Re: New TDI SL user and a couple of questions
Posted by: stephenscool
Date: November 21, 2017 04:53AM
Sweep speed. On the beach I can basically discriminate by ear. Aluminum will be sharp and metallic, steel or iron will drag out slightly (clad) , anything that gives an erratic signal is wire or similar. Pm metals will always give a distinct response

Re: New TDI SL user and a couple of questions
Posted by: DonM
Date: March 01, 2018 09:31AM

Sorry, only registered users may post in this forum.

Click here to login