Polish Pi

[Bayu]

my experience on two sample delay resistors:
i tried 20k for both (27uS sample delay) with a 50cm spiral flat coil about 350uH
detects gold very good but as soon as you try to go over some clean ground it does not work, too sensitive to capacitive effect of ground
have to shield it
but increase the resistors up to 27k both, it works like a champ
40uS delay if i remember correctly and very little ground effect
still catches gold
12gram bracelet 18k : 80cm
2gram ring 14k(not sure) : 17cm

I am seting freq 750hz 33k pin 1 from4011 use 10k
33k use trimp 50k to setting
330 from 6 lf357 replace 10r
Detec ring 1,8grams 18k 17cm in red ground

[Bayu]

@Bayu, what did you use as your schema for the VCO? Please show us.

[Andi68]

The detector gets faster when you get theApplying Sanbanks Mods

[Mr.Jaick]

That's funny.

When you say "detects gold", most people immediately assume you mean gold nuggets. Rings (whether made of gold or not) enhance the flow the eddy currents, and are the easiest targets to detect.

That is indeed
"nuggets" oh boy...
detecting rings with this detector is a big achievement on it's own

[Qiaozhi]

those are the detection depths
we're not giants

That's funny.

When you say "detects gold", most people immediately assume you mean gold nuggets. Rings (whether made of gold or not) enhance the flow the eddy currents, and are the easiest targets to detect.

[Mr.Jaick]

That's a huge bracelet and ring!
I assume you actually meant 80mm and 17mm?

those are the detection depths
we're not giants

[dbanner]

i think his coil is not 350-380uH but less. with 560 Ohm he has to get near-to-good picture.

I concur. The coil itself is under the so called " inhabitable zone".

You may want to wind a new coil, and don't be surprised to see different results.

[Qiaozhi]

12gram bracelet 18k : 80cm
2gram ring 14k(not sure) : 17cm

That's a huge bracelet and ring!
I assume you actually meant 80mm and 17mm?

[Mr.Jaick]

my experience on two sample delay resistors:
i tried 20k for both (27uS sample delay) with a 50cm spiral flat coil about 350uH
detects gold very good but as soon as you try to go over some clean ground it does not work, too sensitive to capacitive effect of ground
have to shield it
but increase the resistors up to 27k both, it works like a champ
40uS delay if i remember correctly and very little ground effect
still catches gold
12gram bracelet 18k : 80cm
2gram ring 14k(not sure) : 17cm

[surfdetector]

[ATTACH]54603[/ATTACH]
[ATTACH]54603[/ATTACH] Green [ATTACH]54603[/ATTACH] Pin 10 4011
Yellow pin 5

@Bayu, what did you use as your schema for the VCO? Please show us.