C.Scope CS990XD

[asolone]

[pelanj]

And how about the today's 1220R or XD? Are there some other good non-motion machines? Is there some physical limitation in depth compared to the motion machines? I am seriously considering getting one, as I have used a Whites 3900 and a Viking 5. I liked the way they operated, but the sensitivity and depth were not great.

I think I need a non-motion machine with ground balance adjustment and iron discrimination

[TH Jim]

Hi Asolone,

Thank you for posting your modifications, I look forward to trying them out Are your modifications taken from a 1220 circuit or did you design them yourself?

Regards, Jim.

[asolone]

Hi Asolone,

Thank you for posting your modifications, I look forward to trying them out Are your modifications taken from a 1220 circuit or did you design them yourself?

Regards, Jim.

for changing the sensitivity I have copied from the 1220b to the modification of the ground is my own invention, the metal part of the potentiometer is connected to the virtual ground to limit the noise, I added a third change, a low pass filter on every channel all metals as present in the scheme of 1220b.
The modification serves to decrease the sensitivity of the channel gain all metals,
potentiometer to the maximum amplification is the original,ruotand the potentiometer to its maximum resistance value decreases the gain of the circuit , you get a better threshold that is more stable and the sound of the channel vco is much cleaner and improves performance on small objects like coins and deep and medals, also in the midst of many signals is easier to distinguish sounds good.
recommend using the headphones for maximum depth and go very slowly with the search coil
my English is not very good, I use google translator

[asolone]

And how about the today's 1220R or XD? Are there some other good non-motion machines? Is there some physical limitation in depth compared to the motion machines? I am seriously considering getting one, as I have used a Whites 3900 and a Viking 5. I liked the way they operated, but the sensitivity and depth were not great.

I think I need a non-motion machine with ground balance adjustment and iron discrimination

Both are good , 1220r is good for coins, 1220xd is good for militaria, 1220xd 1220r-1220b-go deeper,has a fixed adjustment of the audio level of discrimination , while the 990 is adjustable, I prefer the 990xd for the opportunity to adjust the discrimination audio vco.
these metal detectors are not suitable for research on mineralized ground like beach or volcanic soils, with the modification improves performance. I modification10 c.scope 990xd of friends and everyone was congratulating me.
many people do not like metal detectors no motion, I love them, depending on the sound emitting I know what's in the ground
you have to use headphones, and move slow with the search coil for optimal performance

[Eugen]

Hi Asolone and Guys!
Please send c.scope 990xd diagram. Asolone change can be done, if you can help.

[asolone]

Hi Asolone and Guys!
Please send c.scope 990xd diagram. Asolone change can be done, if you can help.

Hello Eugen
I do not have 990xd diagram, there is an old post 990b of the circuit is very similar

[Eugen]

Hi Asolone!
Thank you for your help. The sensitivity test is how much change.
Google translate, because I'm Hungarian!

[asolone]

Hi Asolone!
Thank you for your help. The sensitivity test is how much change.
Google translate, because I'm Hungarian!

the sensitivity is equal with 0 ohm potentiometer and decreases by increasing the value of the potentiometer, the result is better stability of the threshold , vco signal is much cleaner

[Eugen]

Hello Asolone!

Thank you for your answer. I guess the old switches stances after placed your subject. I just changed the sensitivity potentiometer element, because the conditioning is not mineral land.
The inland-beach option remains.
Thanks: Eugen

[asolone]

Hello Asolone!

Thank you for your answer. I guess the old switches stances after placed your subject. I just changed the sensitivity potentiometer element, because the conditioning is not mineral land.
The inland-beach option remains.
Thanks: Eugen

I only use it to audio disc meter, I jumpered the selectors

[Eugen]

Grazie! Molto buona. Congratulazioni.

[asolone]