sensitivity settings

[frogmanungar]

Can anyone tell me what setting is best on the 3030? I have always kept mine on auto sensitivity. Have I missing anything huge? I have concentrated on other programs and the sensitivity settings I have not had time to play with.

 

[Stever0812]

Auto is good when you have good to moderate soil conditions, as the detector is always scanning and making adjustments for the best performance. I pretty much always run in auto +3 all the time and have found targets up to 8 inches down, and feel confident I am not missing anything (i will be going back to many places with the 17 inch coil to see if this is true or not next year). Manual is for bad ground, or when you are just trying to get max depth, and if you can deal with the falsing(i cannot stand falsing personally). It really depends on your local soil conditions to determine what sensitivity you want to use.

 

[Overvoltage]

+1 on the auto +3. Where I hunt I can run in almost full manual sensitivity and I do not gain any depth or detection sensitivity over Auto +3 from what I can tell. There are many threads on this forum discussing the use of manual vs Auto sensitivity and the pro's and con's of each. As Stever said with the CTX in auto+3 if a target (coin size) is under the coil it will see it. I have also found coins 8-10" deep no problem.

 

[bklein]

Last week i was detecting a stormy beach with soft dynamic sand. Very few targets as to be expected but i would hit areas not exposed this much before so i kept my hopes up. I was trying the ctx 11" and 17" with the sensitivity up to 30 sometimes. My question is - is a manual 30 as good or better than an Auto +3 as far as achieving maximum sensitivity?

 

[Stever0812]

Depends on what the numbers are showing in auto +3, what did the left number show? If it showed 30, then borh modes would be at max sensitivity.

 

[Johnnyanglo]

Your mileage may vary, but I've found the manual setting to be too sparky, and lowering the sensitivity defeats the purpose. So, I run in Auto+3 all the time everywhere - when I get a faint hit then I'll put it in manual to double-check. It is true that you will lose depth in +3 compared to Man+30, but I perfer to have stability over the extra depth.

Sensitivity with Dime (in air)


Sensitiivty with Quarter (in air)

 

[Stever0812]

Cool graphic, but what sensitivity numbers were showing while in auto mode? That makes a huge difference in detection depth! If you only got 15 (left number, in green) in auto +3 mode, of course detection depth is going to suffer greatly vs manual on 25, 23, 21, etc.

 

[bklein]

Just what I was going to say - I went to my local park and compared Auto+3 to manually adjusting it and Auto+3 was missing targets found in Manual.
Opened my eyes to how bad Auto +3 can be but maybe it depends on the conditions - thus I asked the question if the max. is the same for both.

 

[Stever0812]

I would have to think that auto +3 will never be the same as manual 30 because auto uses the average of the 3 frequencies, and I dont think any ground anywhere is that good. How deep and what kind of target did you find that auto sens missed?

 

[Jason in Enid]

I would have to think that auto +3 will never be the same as manual 30 because auto uses the average of the 3 frequencies, and I dont think any ground anywhere is that good. How deep and what kind of target did you find that auto sens missed?

That's not how the auto function works. It chooses the quietest of the 3 frequency channels. When you are in manual sens you are using all 3.

 

[KinTN]

Jason, are you saying that in Auto the CTX is only detecting on 1 channel at a given moment?

 

[bklein]

I did not dig the targets. Everyone was saying air tests are not reliable so I keep the targets as original in the ground at a 30 year old park.
I then can raise the coil to see differences in detection between coils like an air test if I want.
After just testing Auto+3 vs Manual I tested 11" vs 17" and saw enough of a difference to return my detector and all coils for an evaluation by Minelab.
The detector had a GPS issue anyway and I had been suspecting a marginal 17" coil and these tests confirmed it.
Targets that the 17" missed could be barely heard with Manual Sensitivity set up high. Never as strong a hit as on a Surf PI or nicely set up XLT with their smaller coils.

 

[mrwilburino]

I would have to think that auto +3 will never be the same as manual 30 because auto uses the average of the 3 frequencies, and I dont think any ground anywhere is that good.

I've hit 30 in auto +3 a couple of times at northern Ohio sites. Was a bit noisy.

 

[Stever0812]

Jason, you are correct I forgot that's how it worked.

 

[ChicagoJohn]

Your mileage may vary, but I've found the manual setting to be too sparky, and lowering the sensitivity defeats the purpose. So, I run in Auto+3 all the time everywhere - when I get a faint hit then I'll put it in manual to double-check. It is true that you will lose depth in +3 compared to Man+30, but I perfer to have stability over the extra depth.

Sensitivity with Dime (in air)


Sensitiivty with Quarter (in air)

Interesting! I use Auto 3+ most of the time and I see that Manual 25 is way up but I did try that before and got so many fault! I mean digging and nothing!

 

[Larry (IL)]

Jason, I think you are confusing Auto sensitivity with noise cancel. From what I understand, the sensitivity in each operating frequency in Auto is adjusted independently and you most likely end up with three channels, each channel has their own sensitivity setting. Manual has only one adjustment for all three frequencies.

In Auto you might have sensitivity of 16-18-20 or 26-28-30 depending on your ground while in manual you will have 30-30-30 or whatever you set it at.

 

[Digger]

Sensitivity controls the detector’s response to received signals from metal targets under the coil, as well as electronic noise and ground noise. Increasing the sensitivity level may make the metal targets more detectable. But it can also increase the detector noise from those other influences. Like you, I pretty much use Auto +3 all the time. When set to Auto Sensitivity, the detector continuously measures the response from the ground and adjusts the Sensitivity level to where it minimizes the effects of those ground signals. Since air tests do not allow for ground noise, their "results" can be very misleading when making a comparison of Sensitivity settings. JMHO HH Randy

 

[CT Todd]

Sensitivity controls the detector’s response to received signals from metal targets under the coil, as well as electronic noise and ground noise. Increasing the sensitivity level may make the metal targets more detectable. But it can also increase the detector noise from those other influences. Like you, I pretty much use Auto +3 all the time. When set to Auto Sensitivity, the detector continuously measures the response from the ground and adjusts the Sensitivity level to where it minimizes the effects of those ground signals. Since air tests do not allow for ground noise, their "results" can be very misleading when making a comparison of Sensitivity settings. JMHO HH Randy

Well said Digger

 

[geofunker]

I use both detetectors CTX 3030 and Deus (1 and 2.5 years)
My experience i.E. with a silver coin d22mm – 20cm deep buried in low mineralized soil:
the CTX: can not give a two way signal in auto +3, in man.:25 shows the coin iffy and a lot of questionable tones (when nails in the soil) during searching,
in auto +3 the target separation (ferrous nearby non ferrous) is excellent (much better as Deus) but the available depth is lower in comparison with Deus.
I tested separate adjustments on CTX but the depth problem exist.

Any suggestions for this problem?

 

[jtalley007]

n/t