Which 3kHz coil for the 505?

[Firefighter42]

Hi all. I just got my 505 and I love it. I'm wanting some opinions on which coil I should get. I mainly search for coins so I want to get the 3kHz coil but should I get the coiltek 6" DD or the 9" concentric? I will only be able to afford one so I would appreciate everyone's input. Thanks in advance.

 

[Old Longhair]

If you're going to hunt trashy sides, then a DD is definitely in order. Before Coiltek produced the DD's, our biggest beef with Minelab was not having one in 3kHz.

The concentric is great if you can use it. If trash density is high, or your area has more mineralized ground, then a DD is the ticket. The concentric in clean mild ground will cover more area and run deeper. In warmer ground, the 9" starts losing depth and the 6" DD starts closing the gap. And if your ground is hot, then the 6" will perform better, but it's possible that a DD in a different frequency might be better yet.

For picking through trash, a 6" DD is what you want. If just coin shooting, then the 3kHz is for you.

If maximum depth is the objective, and ground isn't too warm, and trash density isn't bad, then save a few more shekels and go for the 15" 3kHz All-Terrain. Just understand, you will probably need a shovel, 'cause your hand digger isn't going to cut it.

 

[Firefighter42]

Thanks for the advise Old Longhair. I'll have to do some more testing to figure out the soil around here

 

[ryanchappell]

Just get one to use as a sniper coil. 6" is not wide enough for your main coil, it sacrifices a bit too much depth. I find a 8x6 DD the perfect size for my e-trac, too bad they don't make an 8" DD for the x-terra. I would just use the 9" and switch to the sniper occasionally.

I don't think there is not going to be enough difference between a 9" CC 3khz and a 9" CC 7khz, to warrant having both.

 

[Firefighter42]

Then would you suggest the 10.5" MF DD coil instead for a main use coil?

 

[Jack Beam]

I mainly use the 10.5 mf DD coil,only because of the areas I detect. You can't go wrong with the 10.5 mf DD! When you can afford a different coil there is plenty to choose from! The 6" 3khz DD would be a killer in those trashy spots!

 

[michaelosully]

Firefighter42

Just my opinion ... I'd go with the 6" LF DD that just came out from Coiltek for a LF. But in the interest of full disclosure, I've not found a use for my standard MF CC coil since I now do all my hunting (in all soil conditions) with my 10.5" MF DD and my 6" HF DD.

Had the 6" LF been available a year ago, would have gone with it instead of the 6"HF DD I now have, but it wasn't and I am completely happy with my versatile coil set-up. To me, a concentric coil may be a good, all-around coil but the double D's are my choice for all my MDing.

The 305, and 505 I previously owned were great units and the only reason I now have a 705 is the added features (prospecting, auto GB, backlight, etc) so think you'll find the 505 to be great.

 

[Firefighter42]

Firefighter42

Just my opinion ... I'd go with the 6" LF DD that just came out from Coiltek for a LF. But in the interest of full disclosure, I've not found a use for my standard MF CC coil since I now do all my hunting (in all soil conditions) with my 10.5" MF DD and my 6" HF DD.

Had the 6" LF been available a year ago, would have gone with it instead of the 6"HF DD I now have, but it wasn't and I am completely happy with my versatile coil set-up. To me, a concentric coil may be a good, all-around coil but the double D's are my choice for all my MDing.

The 305, and 505 I previously owned were great units and the only reason I now have a 705 is the added features (prospecting, auto GB, backlight, etc) so think you'll find the 505 to be great.

Thanks for the info. I think I'll probably get the 10.5" MF DD to start with and then save up for the coiltek 6" DD. It seems most people prefer the DD coils, I have yet to use one yet. Then again with rain and snow for the past week I have yet to truly try out the 505 very much.

 

[Rainyday101]

You stated that you haven't tried your 505 much due to rain and snow. I personally wouldn't buy another coil until I had some time on the detector so that you can determine if you actually need another coil for your conditions and style of hunting. What you already have may suit your needs just fine.

 

[glriacol88ssn]

The X-TERRA 705 offers the ultimate detecting experience. Capitalising on the versatility of the range, the X-TERRA 705 can be used for gold prospecting as well as for coin & treasure hunting, simply by switching between available pre-programmed modes.

 

[Firefighter42]

The X-TERRA 705 offers the ultimate detecting experience. Capitalising on the versatility of the range, the X-TERRA 705 can be used for gold prospecting as well as for coin & treasure hunting, simply by switching between available pre-programmed modes.

Ummm...... Thanks for the sales pitch. But I have a 505 and I'm not sure how this adds an opinion to what I asked.

 

[ryanchappell]

To me 10.5" is too big and 6" is too small!!! There really needs to be an 8" DD coil! The whole proprietary signal thing between the control box and the coil is a considerable drawback on both X-terra and CTX detectors! "No Sunray Probe, you can only have what we, Minelab allow you to have!"

I guess you have to settle for changing between the two all the time. Extra lower shafts will help make it easier. Something I will definitely consider on future MD purchases is whether it has an 8" DD coil option.

 

[Firefighter42]

Thanks Ryan. I've gotten to go out and really get to know my 505 in the last week and found my first Silver coins with it. I think when my birthday comes around I'll get the 10.5" for clean sites and then get a 6" for the trashy sites like the basketball court I was detecting the other day. I think stock coil doesn't like my soil I'm constantly getting iron grunts from it in AM mode with 48 then -9 readings with the depth indictor maxed out.

 

[ryanchappell]

Thanks Ryan. I've gotten to go out and really get to know my 505 in the last week and found my first Silver coins with it. I think when my birthday comes around I'll get the 10.5" for clean sites and then get a 6" for the trashy sites like the basketball court I was detecting the other day. I think stock coil doesn't like my soil I'm constantly getting iron grunts from it in AM mode with 48 then -9 readings with the depth indictor maxed out.

If you are in the western part of NC you could have the same really bad soil we have! Be sure to ground balance often, and tweak the sensitivity a lot. Experiment with pushing high sensitivity and compare with lowering the sensitivity, to maximize depth, and ensure that falsing is not counterproductive. The 6" coil may help in the soil. DD coils and Lower frequency are the better choices for bad soil. In my soil I am usually finding silver coins with the E-trac at 3-5 inches deep and the 8x6" seems to cover that depth just right. If I need 6" in depth I usually have to switch to the 11" coil. I do not think I can get more than about 3-4" deep with the 305 and its 6" HF, but that may be enough most of the time.

The DD swath is supposed to help, but the 9" stock coil might not be as good or better than the wider 10" DD. I wonder if raising it off the ground would make it perform like smaller coil?

There are deposits of iron ore that run from here up through Chattanooga into the Appalachians. Western NC has all kinds of minerals that we do not have. At least gold can be found there!