RF Detector circuit design

Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
Hi guys here is my RF Detector circuit. I am not familiar with circuit designing but I could make it and it's working, it can detect Cell Phone radiation maybe GSM band and a little bit WiFi also electromagnetic waves from power sources and AC lines.
What do you think about it?
Can I improve it?
EMF.PNG20191026_15772148.jpg
 
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Papabravo

Joined Feb 24, 2006
12,500
I doubt it. You have no way to couple the RF signal into your circuit, and the anode of the diode is held at GND. You have no feedback so the opamps are probably sitting at the supply rail since they are in an open loop configuration.

Google "Crystal Radio Circuits" for ideas
 
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Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
I doubt it. You have no way to couple the RF signal into your circuit, and the anode of the diode is held at GND. You have no feedback so the opamps are probably sitting at the supply rail since they are in an open loop configuration.

Google "Crystal Radio Circuits" for ideas
It's designed to detecting not receiving RF.
 

Papabravo

Joined Feb 24, 2006
12,500
It's designed to detecting not receiving RF.
I don't think it has been "designed" at all as I understand the conventional meaning of that word. What I see is a diode with the anode at GROUND potential followed by two high gain amplifiers with no feedback. What evidence can you offer to demonstrate "RF Detection"?
 

Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
I don't think it has been "designed" at all as I understand the conventional meaning of that word. What I see is a diode with the anode at GROUND potential followed by two high gain amplifiers with no feedback. What evidence can you offer to demonstrate "RF Detection"?
Maybe I don't know words mean!!! anyway If it's not working can you explain how can I fix it?
My evidence is my eyes.
Circuit is balanced with no RF in input when I inject RF to antenna it change the balance of opamp and I will see electric flow in output.
 
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Alec_t

Joined Sep 17, 2013
10,447
All those straggly wires on the breadboard act as antennas and will pick up interference. That is most likely what results in some deflection of the microammeter if there is some means of rectifying it.
If your opamps are indeed LM358 then their unity gain bandwidth of only 1MHz means that they do nothing useful at WiFi or cell phone frequencies (except perhaps provide a parasitic rectifying function).
Microammeters usually have a low impedance, so if one is connected directly to the output of an opamp as shown then the opamp output is essentially shorted to ground.
 

Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
All those straggly wires on the breadboard act as antennas and will pick up interference. That is most likely what results in some deflection of the microammeter if there is some means of rectifying it.
If your opamps are indeed LM358 then their unity gain bandwidth of only 1MHz means that they do nothing useful at WiFi or cell phone frequencies (except perhaps provide a parasitic rectifying function).
Microammeters usually have a low impedance, so if one is connected directly to the output of an opamp as shown then the opamp output is essentially shorted to ground.
It's not Microammeter. It's 10 volt meter.(look at resistors) Yout can find many cell phone detector circuits with LM358 from Internet. So It will work when some amplified current is in input. Microammeters can't detect raw RF as you know.
 

Papabravo

Joined Feb 24, 2006
12,500
It's not Microammeter. It's 10 volt meter.(look at resistors) Yout can find many cell phone detector circuits with LM358 from Internet. So It will work when some amplified current is in input. Microammeters can't detect raw RF as you know.
You still have not provided any evidence of what exactly is working. Just because you find a circuit on the internet does not mean it is worth anything. I don't think injecting an RF signal to a high impedance input is a good idea. I'm a graduate electrical engineer, so what do I know about magic circuits.
 

Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
You still have not provided any evidence of what exactly is working. Just because you find a circuit on the internet does not mean it is worth anything. I don't think injecting an RF signal to a high impedance input is a good idea. I'm a graduate electrical engineer, so what do I know about magic circuits.
I said before bro, It's very simple and clear it can detect(react) to what I said before.
It's working but as you said it's maybe not a good idea, but I wanted to share.
 

Papabravo

Joined Feb 24, 2006
12,500
I said before bro, It's very simple and clear it can detect(react) to what I said before.
It's working but as you said it's maybe not a good idea, but I wanted to share.
I'm not your "bro" and it is neither simple nor clear what is being detected. You're completely entitled to believe anything you want to believe and promulgate any theories you wish. You are not entitled to shovel loads of fantasy detritus without objection from the community.
 

Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
I'm not your "bro" and it is neither simple nor clear what is being detected. You're completely entitled to believe anything you want to believe and promulgate any theories you wish. You are not entitled to shovel loads of fantasy detritus without objection from the community.
Be careful with your words, it's not fantasy, no one said to you to answer to me. It's my experience if you don't believe it, it's your problem.
 

Papabravo

Joined Feb 24, 2006
12,500
Be careful with your words, it's not fantasy, no one said to you to answer to me. It's my experience if you don't believe it, it's your problem.
Oh ... but I have an obligation, even a duty, to challenge extraordinary claims so that other electronic enthusiasts don't take those claims as revealed truth. There are any number of topics that are banned here because there is no substance to them like: free energy, brown gas, over unity machines, and Stanley Meyer. In these cases extraordinary evidence is required and you have given us...your assertions. So far, they lack credibility.
 

Thread Starter

000SHREDDER000

Joined Apr 9, 2017
49
Oh ... but I have an obligation, even a duty, to challenge extraordinary claims so that other electronic enthusiasts don't take those claims as revealed truth. There are any number of topics that are banned here because there is no substance to them like: free energy, brown gas, over unity machines, and Stanley Meyer. In these cases extraordinary evidence is required and you have given us...your assertions. So far, they lack credibility.
Please don't scare me!!!, your claim about my circuit is not fair and you can't say something is wrong before knowing exactly how it works so I think your knowledge is limited! big lies like free energy and so on doesn't even 1% related with this. Keep in mind you can't blame new ideas or something different are fake before knowing exactly what it is. every one some times can made mistakes even a proffesor. I see your silent supporters in every post without thinking of what is inside of it, it's fair or not so you know (bro!!!) world is like wild west there is no justice.
 
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Janis59

Joined Aug 21, 2017
797
Have meditated about growing trend toward up the 60GHz, 120 GHz, 240 GHz ranges and complete lack of instruments capable to measure any radiation in those ranges. My set of tools have end at 10 GHz and no an droplet over. Therefore would be good to create new class of special detector. Idea for such is to take two ampulae (of say quartz as it not warms at microvawes) filled with - one with organic strong polar solvent (Acetonitrile?, Dimethylformamide?) and other with non-polar protic one (Hexane?, Benzene?). If both sizes of colbs are more or less equal (must choose equal area or volume, or contrary, the mass - may be equalized by mass of quartz/thickness). In RF field one will warm up hardly whilst other will not. So, the environmental temperature will be well compensated. As the best digital thermometer IC are capable nowadays to give figures in 32 bit accuracy (microgrades, yet metrologically invalid), but DIFFERENCE between two such ultra-precize temperature readings will be rather accurate thingy. Thus the Atmel may recalc those temperature figures to the W/m2 figures and show on the display. Very sad but EU-ERAF concourse said to me just now "no money for such project". By the way, such apparatus would have even quality to catch the ultra-short radar pulses, what at airports sometimes may have as much as 60 GHz but pulse duration so short as picoseconds at terawatts scale and then second long - zeroe. Normal instrument never see such hedgehog style signals.
 

DickCappels

Joined Aug 21, 2008
5,941
This detector is pretty sensitive and very broadband. I use it for cell phones, RF remote controls and to verify various other transmitters are emitting.

Only two AA cells (or cells of your choice), very low current draw.

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