17" Coil = trouble

[bklein]

Yesterday I hunted Huntington Beach with my friend Jim and used my CTX with 11" coil. Found nothing special; no targets in the wet, a few in the sand. Today was a nice day so we met at Aliso. He had his new CTX to tryout and I had my 3+ year old one. Since no targets yesterday, I decided to try my 17" coil this time along with WM10/earbuds instead of headphones. Ok something wrong - no controllability of the audio volume. Volume Limit and Volume Gain do nothing. Threshold seems to work. OK where it was set, so I go detect and find several targets and got this earring (got my hopes up) - a CZ I see a guy selling on ebay for $60... South side of Aliso was showing targets, mostly pennies and aluminum nuggets. North side was dry. I decided to look at the audio issue more. Turned the detector off and back on and the audio worked normally - Volume Limit was like a volume control. But I then started to detect and targets were silencing the threshold but you couldn't hear them. By then it was dark so I gave up. Came home, cleaned off the sand and retried and things seemed to work. Interesting to spend time playing with the Volume Gain and Limit controls and see how targets sound out. I'll spend more time on it tomorrow but seems to be a connection issue internally somewhere. Another thing was target depths were too high vs where the target actually was. Out of warranty so I'll have to pin this down myself.
Impressed with small targets found with the 17" when it was working...

 

[IDXMonster]

Just a couple of thoughts which may or may not be of any use....the coil has to be exactly centered on the target for most accurate depth reading. Also small targets will read deeper than actual,as the machine isn't calibrated toward small earrings,rather....coins. Maybe try the regular headphones you use with the WM10 and see if it acts up,if not...a problem with the buds? A factory reset might clear up any corrupted software if nothing else works..."

 

[utahshovelhead]

Its a known that that the larger coil will give different depth readings than stock coil. You get used to interpreting the depth indicated vs the true depth with use or the 17. On the beach I tend to dig deeper than I need to to protect the target anyway.

Also, the 17 tends to grab onto other close objects that are nearby and this can mess up your pinpoint. Ive learned to be quite a bit slower and careful when pinpointing when I feel that there are other metal objects around. Even after I dig out a big hole I first check to see where Im setting the dug out dirt so the ground is clean.

 

[bklein]

The audio problems did not show up in my home testing - I think I'll need to give the setup another workout at a park or beach.
Some things about the 17": the mounting tangs are spaced farther apart than on the 11". I had to install a fiber spacer. The coil cable was about to get totally thrashed at the shaft port so I added a wrap of electrical tape and that plastic cable protection tubing to take the friction. I noticed the coil cover was coming off - maybe I didn't snap it on well enough. I put 4 cable ties front and back - sand getting inside will be a problem though. Might seal with silicone later.
I was seeing different wireless sync behavior depending on what type of headphones/buds I used. I was going through headsets to determine what I liked best. I liked the Koss Pro4A's best but have never detected with them as heavy and really squeeze the ears. My UR30's are at Koss for repair so don't know how they compare. The pro4a's were difficult to sync the wm10. Maybe impedance too low? Have to check. I'll go back to the WM10/buds and see if I get the audio issues after several tries.
It would be interesting to play with settings to see if 17" depth indication changes on the deep ones.
Interesting playing with audio settings to hear how EMI can be put in the background in favor of good coin target hits. I've read threads where guys had a problem with this and playing with these settings can really improve your world.