TDI THRESHOLD ADJUSTMENT ???:rage:

[earthsea]

When I set the threshold with the ground balance toggle ON, I find that there is always some CHATTER to some degree, is this normal? No matter how high I turn up the threshold there is some chatter with the GB toggle on.
When I turn the GB toggle OFF I get a nice pure sound with no chatter, is this pure tone what I should expect when the GB toggle is on?
Also, should the coil be on the ground or above the ground? when setting the threshold, or doe's it not matter?
Good hunting all.

 

[Reg]

Yes, this is normal on the TDI. PI's are historically noisy and depending upon the amount and type of filtering, the noise can be hashy type chatter or a warble present with the GB on.

Now, the GB toggle turns on something called the GB channel used for ground balancing. Because of the signals involved, the GB channel has a lot more amplification than the normal channel, thus more noise. The higher you turn the GB control, the greater the gain which further results in an increase in noise.

If you were to increase the gain or sensitivity of the main channel by itself, you would experience similar noise. Unfortunately, if this is done, then the signal needed for ground balancing would be extremely noisy, making the detector almost unusable.

So, in a nutshell, what you are experiencing is normal.

Reg

 

[earthsea]

Thanks heaps for that Reg, problem solved. I Just love my TDI and crave knowledge on its workings. Thanks again and good hunting.