A Few CTX 3030 Beach Tips

cjc

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Mar 19, 2006
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DFX, GQA2, (2) 'Cuda, Excal, (1 & 2) Sov. Elite, CZ20, Surf Dual Field...
These area few things that worked well for me--I don't expect them to apply everywhere. This is a machine that because of it's complex signal and processing does not like viscosity--fast water or black sand. The answer is coil control and tuning. I set the sens in open screen in the worst interference zone--the wave break, or on an incline to deeper water. I test with a slightly fast sweep speed--that way there's less chasing down of partials. I stay away from Auto--based upon some testing that "JohhnyAngelo" did showing that "22" manual is optimum although "20" or with the 17"-- "19" are more typical. Having set the sens in open screen, where there is really bad ground I go to a second screen that has some rejection--like Jays gold or the box that Andy uses for his gold prog. Jays pattern makes a great screener although nearby iron or the depth of a response may make a good target sound off weakly. Going between open and closed screen will give a lot of information about a response too. I also like Evan's method of going between combined and 50TC to get an idea of how consistent a response is. As a search mode, these screeners require an even slower sweep speed. The "Previous Mode" setting is handy in that it lets you test a second program alongside what you are running to compare--both depth and stabilty. I tested several this way. Andy's gold was a bit deeper than my standard Jay's open screen but the Pitch Hold changed a lot over non-signals at high sens settings. Drayon's 4TC was a lively sounding program owing I guess to there being no low tones to process as with combined. However, it had to be run low to stop ground noises from continually coming in. I will say though that these "dud, dud dud" sound were not the same as the low conductor "hum" of a "12-01/2/3...." that could be a chain (or rotten glasses). I also tested some of the placer gold set ups I got from Steve Hershbach's Detector Prospector site "Gold High Trash / Gold TTF/ Gold High Mineral" this way. These all high toned a lot although they may have been okay down at "19" sens or lower that wasn't the level of sensitivity I wanted to run. I learned a ton of very effective stuff on this trip wish more had gone into the book although a second one is not out of the question.
cjc
clivesgoldpage.com
 

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I have many friends that use them in black sand ---New England is covered in black sand - they don't seem to have any prob with it :dontknow:
 

Gary hunts primarily in Fla. waters - no black sand
 

Very informative post. Never thought about setting the sensitivity in the worst conditions
 

I dont have problems with black sand, its no PI machine we know, but its not like it doesnt like black sand either.

GL & HH
 

I'm in black sand a lot, especially this time of year. It gets a little chatty, but still hittin signals deep just fine, I like her wide open as hot as I can get er!
 

Must be some nice black sand. I get a suggested "6" Sens and not great depth with the stock coil although the 17" seems better haven't done enough testing yet. Wish there was some setting(s) that would bring the performance up to how it penetrates in salt water.
Is that in combined? Just wondering if maybe it's all the iron processing slowing things down.
cjc
 

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I take back my comment lol. Got into some of the worst black sand I've been in today. Buried a few coins to play with settings. The best I could get was maybe a chirp at a few inches, but mostly they were sounding off as iron. Pretty disappointing
 

Ya, some trial and error is called for. I still think the 17" has potential and will punch though the black sand with some tweaking. I've run down every response here (Including Leighton and Steve Z) and no one has any answers. With the Excal--that 800 is a killer in black sand--wish there was a mid sized coil for the CTX that would give the same result. Ive heard a few people say that the 6" does the job but for my liking its just too small to cover any ground. I also found a few ideas from AUS:
http://phasetechnical.com.au/detecting-mineralised-black-sand-beaches/
cjc
clivesgoldpage.com
 

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I wouldn't say there is an optimum Sensitivity setting. It varies with conditions and your brain's tolerance for falsings.
Just run as hot as you can tolerate. I haven't run mine in serious black sand but in several writeups like this one: https://www.minelab.com/treasure-talk/ctx-3030-auto-vs-manual-sensitivity it says to go to Auto. I would think that either is fine - if in manual try for the 20's and if you can't you are losing depth and I'm not sure if there is a way to prevent it. I would suggest someone try a test in such black sands with a 6" coin/gold target - try going through manual NC settings.
If in black sand it might make a difference where the coil is for the first couple of minutes on turn on. Try turning on your detector near a car vs way away from it to see what I'm talking about. Maybe if you do manual ground balance some magical way it could help. Try the variables (up in the air, pumping, on the sand) and then go to that 6" target to check. Try this NC 1, 6, 11 and see if you get different results.
Mode setting might influence the above results too as FC seemed to shift some ID's like bobby pins from null extreme low tone or just threshold cancel to iron tone.
The other day I was looking into the EMI sensitivity the CTX has in my front yard. I covered my coil with aluminum foil and turned the detector on. No target, open screen - took the foil off and still open screen (no target detection). Thought I killed the detector! Repowered without the foil and all is well again thank goodness... So at least try turning on the machine with the coil in the air vs on the black sand and let me know if you notice any detection differences afterwards.
 

We get concentrations of sea weed here in Fl that does collect black sand and will make a detector loose depth fast and chatter. Ive also found going E to W with the lines of black sand will affect TID a little less than moving N to S where you constantly cross these concentrations and you can pick up some of the targets others miss. Most machines also dont like COIL FLIP or any tilting of the coil much. What ive found is multi freq machines dont like fluffy sand or air space either. In Fl, we are chasing a lot more recent drops...... if you can use the 17" to cover move water/sand depth many not matter at the end of the day. BUT ..... having the ability to swap coils and headphones is a huge advantage for the CTX as is tone adjustment. Have you ever tried knocking out a couple of squares on the right side Clive? It seems to work on some machines when the sensitivity is run really high..... it can stop a lot of the wrap around where iron sounds like a high tone.
 

Dew--Ya, "bordered" programs like Andy's gold or Jay's Gold are good fail-safes to quieten the machine down, but still get the extra depth of an open screen set up. I do some ground that's so prime that five or eight rows on the same line is a good idea. In this kind of situation you can see how a "box" like Jay's may hit perfect targets but will miss some too. The P2 in Jays is great (single line at the bottom) as it knocks out some ground noises letting you run higher but still go very deep. I would suggest that as with Andy's gold--leave the 8-14 lines clear. Good tip on the black sand--going crosswise makes any machine crazy.
cjc
clivesgoldpage.com
We get concentrations of sea weed here in Fl that does collect black sand and will make a detector loose depth fast and chatter. Ive also found going E to W with the lines of black sand will affect TID a little less than moving N to S where you constantly cross these concentrations and you can pick up some of the targets others miss. Most machines also dont like COIL FLIP or any tilting of the coil much. What ive found is multi freq machines dont like fluffy sand or air space either. In Fl, we are chasing a lot more recent drops...... if you can use the 17" to cover move water/sand depth many not matter at the end of the day. BUT ..... having the ability to swap coils and headphones is a huge advantage for the CTX as is tone adjustment. Have you ever tried knocking out a couple of squares on the right side Clive? It seems to work on some machines when the sensitivity is run really high..... it can stop a lot of the wrap around where iron sounds like a high tone.
 

Some good tests--that's exactly how it's done--trial and error.
cjc
I wouldn't say there is an optimum Sensitivity setting. It varies with conditions and your brain's tolerance for falsings.
Just run as hot as you can tolerate. I haven't run mine in serious black sand but in several writeups like this one: https://www.minelab.com/treasure-talk/ctx-3030-auto-vs-manual-sensitivity it says to go to Auto. I would think that either is fine - if in manual try for the 20's and if you can't you are losing depth and I'm not sure if there is a way to prevent it. I would suggest someone try a test in such black sands with a 6" coin/gold target - try going through manual NC settings.
If in black sand it might make a difference where the coil is for the first couple of minutes on turn on. Try turning on your detector near a car vs way away from it to see what I'm talking about. Maybe if you do manual ground balance some magical way it could help. Try the variables (up in the air, pumping, on the sand) and then go to that 6" target to check. Try this NC 1, 6, 11 and see if you get different results.
Mode setting might influence the above results too as FC seemed to shift some ID's like bobby pins from null extreme low tone or just threshold cancel to iron tone.
The other day I was looking into the EMI sensitivity the CTX has in my front yard. I covered my coil with aluminum foil and turned the detector on. No target, open screen - took the foil off and still open screen (no target detection). Thought I killed the detector! Repowered without the foil and all is well again thank goodness... So at least try turning on the machine with the coil in the air vs on the black sand and let me know if you notice any detection differences afterwards.
 

That was something I tried was discriminating out the bottom right corner to get rid of all the extra ground noise, still didn't pick up test targets any better, even seemedto lose them more from the mulling of the ground noise. I've only had the 3030 a year now, so still learning all them time. These posts are very helpful! Thanks guys
 

Suggestion. Try even a smaller coil. The less meneralization you place under the coil the less labor on the processor and the more power and better response when punching through that concentration of black sand. Just a suggestion.
 

wish what was available wasn't quite SO small though. The 800 is killer in black sand on the Excal, but 6 is a toothbrush on the beach.
cjc
 

I was workin' a cut today that was the worst yet, I checked the saltwater, that allowed me to bump up the sense a lil bit, that seemed to help a little. What are your guys' thought on ground balancing. There's so many mixed thoughts on it. I tried it and it today also and it didn't seem to help much?
 

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