E-Trac EMI channels

[Jason in Enid]

OK, I have been wondering about this since I first got my E-Trac. Every time I set the EMI reduction it almost always selects channel 6 or 9. Exactly how do these "channels" work? Does any channel have an advantage of the others for silver? What channel does your machine pick most often?

Anybody have any info?

 

[Jack Flynn]

My channels are different at different areas of one given park lets say. Also at the many places I hunt it will always pick the same channel where I start which is where I park the truck and get out. Depending on what I'm next to or close by it will pick different channels too. I think it's actively working like it's supposed to.

 

[Jason in Enid]

OK, but what effect do those channels have on coin detection? Anyone?

 

[The Beep Goes On]

I think that the 11 channels are subsets of frequencies that are offset by a certain amount. The E-Trac uses 1.5

 

[MT]

My favorite channel is 10. I manually set it. Some of the lower channels make my X-1 probe false too much.
HH,
MT

 

[Chris(SoCenWI)]

The Minelabs transmit square waves of a couple different frequencies to generate the multiple frequencies. It samples frequencies from 1.5k to 100k hz. The noise cancel basically just shifts one of the square waves by a small amount which in turn shifts the rest of the frequencies by a small amount. You can actually hear this happen; just hold the coil next to your head phones and press noise cancel. You will hear the shift each step. My understanding is that they don't sample frequencies that fall near fundamental harmonic frequencies from power lines; which is why some channels use less than the 28 frequencies advertised.

Yes, some frequencies perform certain functions better than others, but the amount of frequency change in a noise cancel is trivial.

Chris

 

[silvereagle]

i thought it was set in auto?

 

[Jason in Enid]

i thought it was set in auto?

It auto selects the channel when you press the button, but you have the ability to set the channel to which ever one you want.

 

[Nick A]

OK, but what effect do those channels have on coin detection? Anyone?

None whatever in my experience. My machine typically settles on channels 2 and 10, but has come in other numbers as well. I still find stuff regardless of the channel selected.