What is timming

[Bayu]

timming !!! is that timming ?? what is its use, especially in the type PI metaldetector, still confused in my thoughts about timming, and what effect is produced by this timming arrangement, please enlighten the teachers

in the settings there is a micro sound (uS) setting I'm still confused about how it works

[Mr.Jaick]

timing is referred to the sampling pulse timing, in another word -> where to sample, how much delay from tx turn off and how much sample pulse width
let's take polones circuit that you're building as an example :
the pulse coming out of pin 10 of the 4011 ic is our sample pulse which goes to bf245 to switch on at a specific time window from the signal that comes from pre-amp(LF357 in this case)
that time window(sample) is the place we find metals near coil
these samples are called timings

uS is micro second or 1 / 1,000,000 of a second

[Bayu]

timing is referred to the sampling pulse timing, in another word -> where to sample, how much delay from tx turn off and how much sample pulse width
let's take polones circuit that you're building as an example :
the pulse coming out of pin 10 of the 4011 ic is our sample pulse which goes to bf245 to switch on at a specific time window from the signal that comes from pre-amp(LF357 in this case)
that time window(sample) is the place we find metals near coil
these samples are called timings

uS is micro second or 1 / 1,000,000 of a second

what will happen if the timming polones are set to 75uS ?? and what is the difference if it is set 10uS ???

[Mr.Jaick]

if you set it at 75us it will be very insensitive to many targets especially small ones and pretty much no response to low conductive targets like gold jewellery with higher impurities
on the other hand if you go down to 10uS (assuming that you have the right coil for it + pre-amp) you will get very good response to low conductive targets, gold jewellery and even nuggets
but you will also get more ground mineralization response (like crazy) and ground capacitive loading which will make the machine unusable in practice
you can solve the first issue with ground balancing techniques and second with a shielded coil or maybe a good self adjusting threshold
i mean there's a lot more to it than just lowering the sample with a good coil

my opinion : keep the sample delay above 30us to 35us with these single sample, no SAT machines. especially if you don't shield the coil

[Bayu]

Thanks Mr.jaick, for your sharing