EMI

[markg]

Does EMI reduce the depth capability of the F75?
In other words, if you're hunting in an area where there's a lot of interference and the F75 is real clattery (with the coil not moving), does the interference reduce or rob some of the transmitting/receiving signal (which would also reduce depth)?

 

[Shambler]

I don't think so.... it just reduces the amount of time you're willing to hunt with it

 

[Hightone]

Electronically..................yes.

It would be like trying to hear someone talking in a crowded noisy room. Like ground balancing, you want the return signal from the transmitter to be as pure as possible to allow the circuitry to make an unobstructed analysis of the return signal. Throw extra ambient waves into the mix only confuses the processor to the point that it doesn't know what to do with the extra foreign signals. Since the EMI is usually not as powerful as the transmitted signal from the coil, turning down the sensitivity allow the detector to only hear the coil signal, stops the chatter. Though deep targets would register during chatter, you would have a much harder time distinguishing the target, though if you are really good, it could be done.

 

[jbow]

Edit: I re-read your question and personally I don't think the noise it makes when the coil isn't moving has anything to do with depth or finds... again, watch Bill Ladd's video.

Julien

 

[Shambler]

Electronically..................yes

I'm not sure that's correct. I think the problem is the user's brain being able or willing to decipher the difference between EMI and real targets. I can't imagine a manual adjust detector could have "depth" effected by EMI. Now, in the Explorer line, maybe. When you use auto-sensitivity and auto-tracking - a ton of EMI could cause a loss in depth.

 

[Hightone]

High voltage induction and Electro Magnetic Interference is absorbed by anything that can't take the signal and run it to ground. Shielding helps, but you are basically swinging an antenna (the coil as well as the cord from coil to processor). The more you sensitize the unit, the more you are going to hear the ambient signals not produced by the coil transmitter. Filters can only do so much, since the ambient signals are all over the spectrum. Believe anything you like. I do this for a living, removing ambient signals traveling in industrial and commercial applications that effect different low voltage equipment functions.

 

[Cal_Cobra]

EMI absolutely can and will affect depth. I hunt several bay area city parks that are loaded with EMI which limits most detectors, even renders some unusable.

 

[Shambler]

In your business application, the effects of noise on your circuit might be significant, but if you test this application, WITH the F75, it doesn't seem to.

This is in the "F" series forum so I always assume that a discussion about EMI is with the F75 and F70 . If you take the F75 out to a field with no EMI and test it with a high conductor at a disc of "6" - then bring it in the city or in the house and let it go whacko (which it does well!) and test it, you will see almost no difference in depth - the tone is there - the TID is for the most part unusable because of the speed with which its changing. No normal person could hunt in those conditions but the depth doesn't seem to be effected.

Give it a shot

 

[Low-Boy/LCPM]

My take on this is you don't lose depth you lose the the ability to hear targets or lock in on targets. So your machine just won't function the way it should. That happened to me in SF this weekend but I went with the 5DD and it made a big difference but I do think it also acts like masking and you don't hit on targets the way you would with no EMI...