Hello, ferrite rod coupling inductor, I dont understand

[michael1978]

hi to everybody,

can somebody tell me, ferrit rod coils, is a transformer?
if yes how do you calculate? what is the formula

how you select the coupling inductor L2 or L3...

because like i read the maing inductor must connect to capacitor(for frequency to find min and max i understand)
but what about L2 or L3 is the output ferrit rod

So now how is formula ? is transformer,
i find very importand for me thanks..

 

[scottdave]

It is difficult to understand what you are asking. Do you have a specific example? If so, please show what you do understand, and what you are having trouble with in the circuit.

 

[Rive]

Is this about your previous ferrite rod antenna topic?

The answer is a kind of 'yes'. That's why you can tune with one coil, and take the signal from the other (with the first coil designed for selectivity, ant the other is for the required impedance of the following amplifier stage).

However, I don't know how should it be calculated since it is not really my area.

 

[michael1978]

It is difficult to understand what you are asking. Do you have a specific example? If so, please show what you do understand, and what you are having trouble with in the circuit.

yes i have
here the circuit

 

[michael1978]

Is this about your previous ferrite rod antenna topic?

The answer is a kind of 'yes'. That's why you can tune with one coil, and take the signal from the other (with the first coil designed for selectivity, ant the other is for the required impedance of the following amplifier stage).

However, I don't know how should it be calculated since it is not really my area.

so is kind of transformer, i know the main coil with vc, but the oupling i don't understand, can you show me one example please?

 

[Rive]

As I said, it's just not my area, I can't help.

If you could not get help so far, then I would suggest an old style 'offline' library with a decent collection of books about electronics from 50' to 60' or so.
Sometimes there is no help on the internet.

 

[Svein]

This circuit is an example of a regenerative receiver which was popular back in the 1940s or so (when radio tubes were expensive). The circuit around the ferrite rod creates a tuned antenna with a slight positive feedback trough Q1. L₁ and C_V is the tuning part. Q₂ isolates the Radio Frequency part from the Audio Frequency part. D₁, C₃ and R₆ is the AM (Amplitude Modulation) demodulator.

 

[michael1978]

This circuit is an example of a regenerative receiver which was popular back in the 1940s or so (when radio tubes were expensive). The circuit around the ferrite rod creates a tuned antenna with a slight positive feedback trough Q1. L₁ and C_V is the tuning part. Q₂ isolates the Radio Frequency part from the Audio Frequency part. D₁, C₃ and R₆ is the AM (Amplitude Modulation) demodulator.

ok, so we leave regenerativ, for example if we want coupling L2 only main with vc resonant and coupling how to know how many turns?

 

[michael1978]

As I said, it's just not my area, I can't help.

If you could not get help so far, then I would suggest an old style 'offline' library with a decent collection of books about electronics from 50' to 60' or so.
Sometimes there is no help on the internet.

exactly i search a lot...before i asking in forum

 

[Svein]

ok, so we leave regenerativ, for example if we want coupling L2 only main with vc resonant and coupling how to know how many turns?

The regenerative setup changes the sensitivity of the tuned circuit, therefore you need another schematic.

 

[michael1978]

The regenerative setup changes the sensitivity of the tuned circuit, therefore you need another schematic.
View attachment 224182

Thankss man