AMX RX

[Tinkerer]

both coils AWG22 ?

For the receive coil I use AWG 30 wire wrapping wire. The resistance of the coil is about 7 Ohm, very little current.

I tried TX coils with AWG 22 magnet wire and a fishing line spacer between the wires. It works, but the interwire capacitance and resistance is a little higher.
Using genuine Litz wire we could probably go with AWG 24 wire as it has significant lower resistance due to the Skin Effect.

Insulated, AWG 22, 1x19 tinned wire is a good compromise for TX.

Lower TX coil resistance reduces the RX offset.
Thicker wire is heavier.
The weight of the coil is an important ergonomic factor.
Like always a compromise has to be found.

http://www.miscel.dk/MiscEl/miscel.html This is the very useful calculator I use for most coil calculations.

[David_1]

both coils AWG22 ?

[Tinkerer]

AMX_RX_PREAMP_01-27-2023 - Schematic.pdf

Here is a tentative preamp. I did some real testing with this and a real CCPI TX, using an 8" DD coil.

ivconic, if you want to use the 037 opamp, take advantage of the opamp offset correction. I am interested to see what delay you can achieve with this opamp. Probably you need to reduce the gain in the first opamp and add gain later.

[Tinkerer]

RX_REACTIVE_FILTER_DIFFERENTIAL_01-27-2023 - Schematic.pdf
Here is part of an RX circuit that measures the power absorbed by the ground and the target.
Or we could say the REACTIVE signal during the Flyback.
C29 and C26 need to be of about double the voltage of the Flyback.

The circuit is very sensitive.