Sand Shark spikes

[highlander1]

I'm not new to metal detecting but new to Tesoro's Sand Shark. I've had it on several beaches and found numerous coins, rings, bottle tops galore,wire and nails. And all finds are decent depths 4-15 inches. I make my adjustments to get a nice even threshold turn it back to VCO and thats when the fun begins. It seems like the threshold pulsates or spikes every minute or so. Kind of like its self-adjusting, it's really distracting because it sometimes sounds like a hit. New batteries seem to help a little but not much. While getting the spikes I'll do a battery check and still get 6 or 7 beeps meaning the batteries are still in good shape. Is this natural for the spikes, is there any fine tuning I need to do to or is just the nature of the beast. I love this MD to death but I just can't stand the spikey threshold. Any help out there

 

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[Terry Soloman]

I'm not new to metal detecting but new to Tesoro's Sand Shark. I've had it on several beaches and found numerous coins, rings, bottle tops galore,wire and nails. And all finds are decent depths 4-15 inches. I make my adjustments to get a nice even threshold turn it back to VCO and thats when the fun begins. It seems like the threshold pulsates or spikes every minute or so. Kind of like its self-adjusting, it's really distracting because it sometimes sounds like a hit. New batteries seem to help a little but not much. While getting the spikes I'll do a battery check and still get 6 or 7 beeps meaning the batteries are still in good shape. Is this natural for the spikes, is there any fine tuning I need to do to or is just the nature of the beast. I love this MD to death but I just can't stand the spikey threshold. Any help out there

Hello Highlander! No This does not seem "normal." Let's start with your settings. What are they? Pulse Width at 1/2 - 3/4 - Max'ed out? Theshold set a barely audible? How is your coil wire wrapped? Do you run it straight up the lower plastic rod then wrap it around the upper metal rod, or is it all wrapped around the lower plastic rod? You say it is fine in Normal, but spikes only in VCO? Does this happen on EVERY beach, or just certain ones? Does the spike happen at the ends of your swing, in the middle, both?

Spikes can be caused by EMI (CCTV; buried electic dog fences; radar; Power lines; even passing airplanes), poorly wrapped coil wire, too much pulse width.. Looking forward to trying to help you out..

 

[highlander1]

Hello Highlander! No This does not seem "normal." Let's start with your settings. What are they? Pulse Width at 1/2 - 3/4 - Max'ed out? Theshold set a barely audible? How is your coil wire wrapped? Do you run it straight up the lower plastic rod then wrap it around the upper metal rod, or is it all wrapped around the lower plastic rod? You say it is fine in Normal, but spikes only in VCO? Does this happen on EVERY beach, or just certain ones? Does the spike happen at the ends of your swing, in the middle, both?

Spikes can be caused by EMI (CCTV; buried electic dog fences; radar; Power lines; even passing airplanes), poorly wrapped coil wire, too much pulse width.. Looking forward to trying to help you out..

Pulse Width is at factory setting or less (11:00)
Threshold is barley audible, volume up a bit to hear over waves
Coil wire is wrapped, after reading more I found out it shouldn't be
Not fine in normal, spikes the same on both settings
Happens on all beaches even not on beach...farmlands and woods of WV
Spikes happen anytime all swings (both right and left)
Nothing really around (EMI) noticeable
I'll straighten out the cable and see if that helps and post the results...thanks

 

[Terry Soloman]

Pulse Width is at factory setting or less (11:00)
Threshold is barley audible, volume up a bit to hear over waves
Coil wire is wrapped, after reading more I found out it shouldn't be
Not fine in normal, spikes the same on both settings
Happens on all beaches even not on beach...farmlands and woods of WV
Spikes happen anytime all swings (both right and left)
Nothing really around (EMI) noticeable
I'll straighten out the cable and see if that helps and post the results...thanks

I hope it is just your wrap. Check mine out..

 

[highlander1]

OK..I have my cable wrapped as you suggested and it did help with the spikes. The threshold is steady on "F" adjustment but still erratic on VCO and Normal but not as bad as it was, so is this erratic threshold common or do I need to do something else.

 

[JKPK1]

Is it possible that you have the threshold set on the "ragged edge" and maybe it needs to be backed down just slightly? As Terry mentioned, with the cable the straight up the shaft seems best. Also, be certain the strain relief loop at the coil is not moving back and forth with each swing causing it to false.

One other small concern I had with my Sand Shark, and this is not a Tesoro problem, was that as I swung the coil, I tended to not have it parallel to the ground. For whatever reason, this caused me to catch an edge randomly, and also give weird signals vs finds.

My solution was that I redrilled the lower shaft at the angle I preferred the handle to coil relationship to be. Once drilled, I moved the pin clip into the new holes. The holes were repositioned slightly below the oem holes, and clocked as needed. This can be tested by disengaging the pins, rotate the lower shaft, and lock the clamp. If found better then you can drill. While not a reversible mod, it is not a hack mod either and is not seen nor detrimental, plus a new lower shaft is inexpensive.

Not saying this is the problem, just a consideration.

PK

 

[highlander1]

Is it possible that you have the threshold set on the "ragged edge" and maybe it needs to be backed down just slightly? As Terry mentioned, with the cable the straight up the shaft seems best. Also, be certain the strain relief loop at the coil is not moving back and forth with each swing causing it to false.

One other small concern I had with my Sand Shark, and this is not a Tesoro problem, was that as I swung the coil, I tended to not have it parallel to the ground. For whatever reason, this caused me to catch an edge randomly, and also give weird signals vs finds.

My solution was that I redrilled the lower shaft at the angle I preferred the handle to coil relationship to be. Once drilled, I moved the pin clip into the new holes. The holes were repositioned slightly below the oem holes, and clocked as needed. This can be tested by disengaging the pins, rotate the lower shaft, and lock the clamp. If found better then you can drill. While not a reversible mod, it is not a hack mod either and is not seen nor detrimental, plus a new lower shaft is inexpensive.

Not saying this is the problem, just a consideration.

PK

I'll do some playing around with the threshold adjustment. I've done air adjustments to rule out swinging problems, cable problems and coil being parallel to ground. Moving the cable really helped with the spikes.
All I really want to know is, what the tone is from everyone else's SS like in the VCO mode. Is it a consistant stable tone (like the tone in "F" adj position) or is it an consistant eratic tone??

 

[Terry Soloman]

Highlander, my guess is the threshold may be just fine, as it is never a "smooth buzz." The spikes were not normal. You are using the threshold as a tool with the Sand Shark, and if it is too loud or not audible, you'll miss deep targets. It takes at least 50-hours on the headphones to get used to this machine, and that is why I tell all new Sand Shark users to start in NORMAL mode. Once you have Normal dowm, THEN you can start playing with VCO. If you still don't feel the machine is acting right, send it in for service.