ALONSO PD MISSION ACCOMPLISHED V1,V2

[brain]

hello geo
Is there a local oscillator at these frequencies.when passive or active

I will share the fm receiver circuit

I want to review this. Does it look like alonso pd
[IMG][/IMG]

[humhum]

From my experimets... i found buried objects with below frequencies...

60Khz,62 Khz, 75Khz, 78Khz, 80Khz, 84Khz, 88Khz, 92Khz, 100Khz, 125Khz, 133Khz, 250Khz, 500Khz, 513Khz, 1Mhz,80Mhz, 84Mhz,110Mhz,438Mhz.
Do you mean that all these frequencies are special frequencies??? or the gold emmits a signal at these frequencies???

Ok , this is your success , but in me not is so , for full FM sensitive working system it is
only in some special frequency ,
also dear Dubulumatch and Esteban say about special phenomenon frequency in FM .

In my last attempt with FM, the phenomenon burned out the Buzzer floor of my device, I was very surprised .

[Geo]

hello geo
Is there a local oscillator at these frequencies.when passive or active

I will share the fm receiver circuit

I want to review this. Does it look like alonso pd
[IMG][/IMG]

Yes Q1 works as local oscillator. You can make it to oscillate between 80 and 110 Mhz by playing with coil and trimer ....

[brain]

Ok , this is your success , but in me not is so , for full FM sensitive working system it is
only in some special frequency ,
also dear Dubulumatch and Esteban say about special phenomenon frequency in FM .

In my last attempt with FM, the phenomenon burned out the Buzzer floor of my device, I was very surprised .

hello humhum
What is the fm receiver frequency.?
Are you using 80mhz or 110mhz?
What is the IF frequency? Is it possible to write them.

[abdou2014]

Hi Brain , why you don't use display ?

[brain]

I'm trying to figure out why. I partially understand that we are evaluating the electrical value of the electromagnetic field. I am looking for another solution as it is not the tda7000.

[abdou2014]

but you need a good display to catch the small variation

[brain]

What is a display?

[abdou2014]

audio meter

[brain]

I will deal with the microcontroller, I need important points.
with a 125khz frequency microcontroller for Tx I did . Important points are required for Rx.

[humhum]

hello humhum
What is the fm receiver frequency.?
Are you using 80mhz or 110mhz?
What is the IF frequency? Is it possible to write them.

I can't measure my setting FM receiving frequency , because it is very power low signal ,
, IF of some FM receiver is 10.7 Mhz , IF of AM receiver is 455Khz , This is after
mixing of input and local OSC , but TDA7000 not use 10.7Mhz , only few Khz .

about IF see this link :

https://www.analogictips.com/radio-receiver-architectures-part-1-trf-superhet/

https://www.analogictips.com/radio-receiver-aarchitectures-part-2-zero-sdr/

[abdou2014]

I finished my new TDA system, very sensitive for the electric field,detect a laptop at 4 meters, an antenna cable at 1.5 meters, a problem with the buzzer, the sound very weak ,

[abdou2014]

sound problem solved I think a colpitt oscillator is better than the NE555

[Geo]

For audio signals i believe that 555 is the best choise

[abdou2014]

Thank you Geo