RX - Mini PCB - Resistor and Filters

[Daves]

Hello,
There is a small PCB inside some coils. Here, the wires coming from the coil are generally transferred to the coil cable, but some devices also have a few parts.

For example, I think there is a resistor at the Rx input. What does this resistor do?

I see different materials are also added, what are the filters used in the rx front end?

[Carl-NC]

It depends on the design of the coil. Many coils (especially older ones) would passively tap some TX signal and feed it into the RX for X-null or R-null purposes. This was often because the coils ran high inductances with correspondingly high parasitics, and there were a lot of variations on how this was done. Modern coils tend to run much lower inductances and don't need the compensation.

[Daves]

It depends on the design of the coil. Many coils (especially older ones) would passively tap some TX signal and feed it into the RX for X-null or R-null purposes. This was often because the coils ran high inductances with correspondingly high parasitics, and there were a lot of variations on how this was done. Modern coils tend to run much lower inductances and don't need the compensation.

Can you say something about the example in the picture?

[Carl-NC]

I have no idea what that is or what it does.

[ivconic]

Looks like frontend with ADC included.
Also can be anything else.
If you can provide accurate writtings from a chips; guessing game can be narrowed.
Funny questions you ask Daves!

[Daves]

Looks like frontend with ADC included.
Also can be anything else.
If you can provide accurate writtings from a chips; guessing game can be narrowed.
Funny questions you ask Daves!

It wouldn't be bad if you shared some tips, ivkonik

[ivconic]

It wouldn't be bad if you shared some tips, ivkonik

First step to make a good guess is to clearly read what's written on the chip.
I have troubles recognizing the labels on the photo.

[Daves]

First step to make a good guess is to clearly read what's written on the chip.
I have troubles recognizing the labels on the photo.

I know you love analog designs, I would have thought you would recognize this type of analog circuits as soon as you saw them and I thought you already knew

[ivconic]

I know you love analog designs, I would have thought you would recognize this type of analog circuits as soon as you saw them and I thought you already knew

I wish I am so smart!
My best gueess is what I said earlier; probably a frontend.
Is it ADC chip there too? Can't say, cant recognize the inscriptions.
I think I see 4 wires comes to pcb. So it is probably a pcb from a searchead.
So what such pcb can have? A frontend(s).
Of course I can be wrong.
...
Indeed I love analog desings.
One simple reason; I can't keep up with ongoing progressive technology.

[Daves]

I wish I am so smart!
My best gueess is what I said earlier; probably a frontend.
Is it ADC chip there too? Can't say, cant recognize the inscriptions.
I think I see 4 wires comes to pcb. So it is probably a pcb from a searchead.
So what such pcb can have? A frontend(s).
Of course I can be wrong.
...
Indeed I love analog desings.
One simple reason; I can't keep up with ongoing progressive technology.

I understand you about technology, lastly I want to ask this. What's in the RX frontend circuit?

[ivconic]

I understand you about technology, lastly I want to ask this. What's in the RX frontend circuit?

Usually one or two opamps.

[kt315]

I have no idea what that is or what it does.

pcb from xTERRA coil, Minelab. with programmed micro on principle of military airdefence system 'SELF - ALIEN' request. alien coil will be not not working.
kinda a protection from ML.