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E-TRAC - Manual versus Auto features for expert users

January 10, 2011 11:40am
The E-TRAC has some very useful ‘Automatic’ features that allow users to find targets at great depths from day one.
Auto Sensitivity and Auto Noise Cancel work together to stabilise the E-TRAC’s performance, limiting noise from iron, changes in mineralisation and electromagnetic interference (EMI).
Although both of these auto features work perfectly well, experienced users wanting to squeeze extra performance from their E-TRAC soon switch to Manual Sensitivity, and in doing so increase their find rate.
In this blog I’m going to argue the virtues of also manually setting the noise cancel feature.
So what does changing the Noise Cancel achieve?
The E-TRAC has eleven different channels numbered ‘1’ to ‘11’, and each of these changes the frequencies that the E-TRAC operates on. So changing the Noise Cancel channel of the E-TRAC can effectively reduce the effects of EMI. This is essential when working near powerlines or when detecting with friends also using a Minelab FBS technology metal detector.
One of the things not widely known about these Noise Cancel channels, is they can directly affect the E-TRAC’s performance. This effect isn’t really noticeable when using Auto Sensitivity, but when using Manual Sensitivity “maxed” out, the Noise Cancel channel can dramatically change the audio responses of the E-TRAC.

In Europe we tend to search for thin section bronze and silver coins. We use minimal discrimination, digging all non-ferrous targets regardless of size.

Coins found by an E-TRAC metal detector

Coins found with the E-TRAC

For this kind of detecting I personally prefer to have Sounds set to Conduct (see page 65 of the manual), giving low to medium tones on the most desirable finds. Audio signals from iron and mineralisation changes are altered using the ‘Smooth’ Response (see page 62 of the manual) and a minimal discrimination pattern. The false signals become shorter than the smooth positive targets, and are usually higher pitched. Tiny deep non-ferrous targets are shorter and low toned.

Once this has been achieve it is possible to increase the Volume Gain and Volume Limit to a level that increases all noises (good and bad), increasing performance exponentially. Using the E-TRAC like this takes a lot of practice, and relies on consistent sounding false-signals (e.g. high-toned and short sounding).
Whilst perfecting this technique I noticed problems when searching at Rallies and fields with power lines. On these occasions the high pitch chatter became low-toned and smoother, causing me to dig lots of false signals. On one occasion I gave up deciding my search coil was faulty…. But it wasn’t!
It took me a while to figure out what was happening. When detecting near electrical powerlines or near other detectorists using similar frequency detectors, it became necessary to use the Noise Cancel feature. Using the auto feature in these difficult conditions I discovered the E-TRAC settled on a setting of 10 or 11 (the top end of the range). For a program using conduct sounds, this isn’t a good place to be, especially when being used flat-out. The falsing becomes low-toned, sounding exactly the same as deep thin sectioned silver hammered coins, rendering my program useless unless switching to auto-sensitivity.
Once I realised what was happening, I could preserve my program by changing the channel to the low end of the range (between 1 and 4).

So to recap – Auto features are preferred for programs where settings are achieving quiet performance (no falsing).

E-TRAC metal detector screen

E-TRAC with Noise Cancel channel set to channel 2 

Using Manual Sensitivity and Manual Noise Cancel is a better way of increasing performance. A Manual Noise Cancel setting of between 2 and 4 are probably the best to use with Sounds set to Conduct, and should be your first choice before looking elsewhere in the range.

Now go out and find something!
Gordon Heritage

Comments

Thank you for a load of great information Gordon. I will immediately try this. I am amazed at the depth and sensitivity of the E-TRAC, especially on small deep objects. No doubt, this is Minelab's best ever. I cant wait to see what the future holds. Thank you, Bill
Posted By: williamweaver on January 17, 2011 12:41pm
I did not know this, I do now! - i'm going to go over some old ground and see what happens. Looking forward to trying out this top tip. Thanks very much.
Posted By: MartinG21 on January 27, 2011 11:18pm
I am in the US and use several different coin patterns that use multitone conductivity sounds. Should I be using the manual noise cancel instead of the auto when using these programs?
Posted By: Bell-Two on March 05, 2011 03:08am
If running auto-sensitivity, you will be OK selecting auto-noise cancel. Also if your coin pattern is anything more than a couple of bars at the bottom of the screen, this probably won't affect you.

If you are using manual sensitivity, minimal discrim and running high levels of gain... I would pick a quiet manual noise channel.

Personally I always choose a manual settings, and select a noise channel of between 2 and 4 (2,3 or 4).

Try it and see if your find rate increases!
Posted By: Ironhearted Gog on March 07, 2011 09:31am
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