Deepstar coil

[Anonymous]

Can a 15" or 18"coil be made for the Deepstar?

 

[Anonymous]

[No message]

 

[Anonymous]

Hi John and Russ,
I have made larger coils for the Deepstar as specials, but they have been a bit tricky to set up to work at 15uS. This is partly due to the extra capacitance of the shielding which lowers the coil's self resonant frequency and hence the damping has to be different. However, I now have a different winding technique which results in reduced capacitance, so presumably large coils will be easier to set up. I say presumably, because I have only yet tried it on 10 and 11in coils where it showed an improvement. The next standard size up is 15in. Beyond that, coils have to be fabricated in plastic piping. I once made a 30in coil for a Deepstar this way, but it was unshielded and was subject to ground capacitance effects.
You can, of course run at a later sample pulse delay, say 25 or 30uS and then shielding is not so important. You will however lose sensitivity to smaller targets.
Eric.

 

[Anonymous]

Eric and Freinds humor me for a moment. Lets say that I want to find a canning jar full of coins. The lid is 5" round and its made of iron. All metal detectors (VLF) will see this as a iron object so discrimination is turned off and I'll be hunting in all metal for the hunt. The quart size jar is just out of reach on the 12"coil on my VLF detector I'm using so I turn to a Two-Box detector. This unit will be subject to gound mineralization and will have to be balanced but you still can encounter problems some of the time even after balancing it properly. Now the 64 Thousand dollar question: What can a PI specifically set up for a cache hunting do that a VLF with a 12" coil along with a Two-Box can't. QWhere does it fit in? Again forget the coins, we are discussing fist size and larger metal objects. Thanks. PS MY local detector dealer who is a cache hunter uses the Minelab SD series with an 18" loop for his cache hunting.

 

[Anonymous]

and the answer is there already, maybe you never got to read them, but in a nutshell, the PI's are real great for fist-coffee can sized iron objects. I went over the beach I mentioned with a Sovereign and 12" coil and never had a reading on the 3" or so round iron object. It was easily picked up with my Beachscan/11" coil which is very simular to the Goldquest being sold (the Goldquest has a few refinements and more adjustments). Those large 2 box detectors are usually TR or VLF's and made mainly for coffee size thru boat sized items. A PI with 10"-15" coils is more sensitive for the fist-coffee sized items with no ground problems in most areas. A more expensive Minelab GP or Deepstar will work for sure, but a decent PI with a 11" coil or (preferably even) larger will do the job just fine. That's my opinion from years of detecting and I am not biased to any company. Just from trial and useage. JCP/Ct.

 

[Anonymous]

i like to use my 15 inch search coil on my deepstar,i have not got the modification done to my deepstar to make it the same as the aquastar.
if i have the change done to my deepstar to make it 10us will i still be able to use my 15 inch coil.
thanks for any responses

 

[Anonymous]

Hi James,
I have not modified any Deepstars to run at 10uS. Existing Deepstar coils, both 11in and 15in, are not suitable for 10uS delay as they have too high an inductance. The mods that can be done are, adding a transmitter power switch and a variable SAT control.
Eric.