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The Amazing All-Band Receiver

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000SHREDDER000

000SHREDDER000

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Hi there, I am back:-?, a few days ago I found a circuit in the Internet, circuit maker claimed it can receive many frequency at same time, yesterday I build it but it doesn't work.
also it doesn't work on simulator above 1Mhz, can someone tell me The truth about it?
can I change R7 and R4 to 1M, R6 to 10k, C6 to 100pf for more output power?

pp.PNG
 

It probably does receive many frequencies at the same time, subject to the upper limit set by construction, transistor Ft and component parasitics. All it though is a lightly biased detector and an audio amplifier. What are you expecting to come out of it?

To be able to receive a radio station you need a method to select it from the background and eliminate all the frequencies you DON'T want to pick up. There is nothing in that schematic to do that. It has no tuning mechanism.

Different component values will not improve the output and the changes you suggest will probably make it work even less efficiently, especially R7.

Brian.
 
I can put a tuner and a demodulator into it. but in the simulator it gives me higher output when I changed values, anyway I want to know can it works correctly or not?

This is better version:

Captuccre.PNG

What about this one:

ww.PNG
 
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000SHREDDER000 said:
I can put a tuner and a demodulator into it. but in the simulator it gives me higher output when I changed values, anyway I want to know can it works correctly or not?
Click to expand...

You are trying to demodulate a signal supposedly in the megahertz range with an operational amplifier designed to operate on the audio frequency.
 
First tell us what you are trying to receive.

All you have is a rectifier and audio amplifier. In the second CAD schematic you add a twin-tee oscillator which will do nothing to help you receive anything. It might mix a VERY strong input signal around 17KHz to a lower frequency but I doubt it would even be very good at that.

Your hand drawn schematic is just a simplified version of the previous one with an added switch. It will do something but we are still confused about what you want to achieve. None of the circuits seem efficient and certainly do not fit the "Amazing All-band Receiver" title of your post.

Brian.
 
andre_teprom said:
You are trying to demodulate a signal supposedly in the megahertz range with an operational amplifier designed to operate on the audio frequency.
Click to expand...

I think it can work at higher frequencies, What can I use instead of it?
 

000SHREDDER000 said:
I think it can work at higher frequencies, What can I use instead of it?
Click to expand...

Your belief is based on what technical basis? At least the operational amplifier datasheet clearly show it start decreasing its open loop gain well below the megahertz range. Moreover, as Brian already mentioned and repeated above, it is missing fundamental circuits of standard receivers in your scheme. And to complete, you did not even mention what kind of demodulation, or what frequency band you want to work with.
 

andre_teprom said:
Your belief is based on what technical basis? At least the operational amplifier datasheet clearly show it start decreasing its open loop gain well below the megahertz range. Moreover, as Brian already mentioned and repeated above, it is missing fundamental circuits of standard receivers in your scheme. And to complete, you did not even mention what kind of demodulation, or what frequency band you want to work with.
Click to expand...

Really I didn't saw that,It's really bad news.
Do you know better model of audio amp for wider frequency range, I don't want to demodulate and select any range of frequency right now before completing this circuit, below circuit is without audio op amp, I can put on a sensitive crystal earphone into output also.

3.PNG
 
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Reviewing the apparent source of information http://www.techlib.com/electronics/allband.htm reveals confusion already in some of the original circuit schematics, but you get a least a glimpse of what they try to achieve.

The final paragraph is describing the hand sketched schematic copied in post #3. It raises serious doubts that the author of this compilations actually understands demodulation principle.

- - - Updated - - -

I like to suggest a different approach: Specify the purpose of your design, e.g. which wireless signals you want to detect.
 

FvM said:
Reviewing the apparent source of information http://www.techlib.com/electronics/allband.htm reveals confusion already in some of the original circuit schematics, but you get a least a glimpse of what they try to achieve.

The final paragraph is describing the hand sketched schematic copied in post #3. It raises serious doubts that the author of this compilations actually understands demodulation principle.

- - - Updated - - -

I like to suggest a different approach: Specify the purpose of your design, e.g. which wireless signals you want to detect.
Click to expand...

First of all I said at first I found it on the internet, Second I know demodulation, but as I said before I don't want to demodulate FM, just I want to know these circuits works well or not.
 

My comment is about the techlib author.

In my view, none of the circuits works "well", some not at all. Problem is however the lack of specification, which signals do you want to detect respectively demodulate?
 

FvM said:
My comment is about the techlib author.

In my view, none of the circuits works "well", some not at all. Problem is however the lack of specification, which signals do you want to detect respectively demodulate?
Click to expand...

Thank you, If none of the circuits works "well" which other Experts said before, I have only one question, How can I correct them?
It's designed to receive a wide band of frequencies so I want to simply receive them without tuning and demodulating specially FM, You think I want to receive audio sound form different bands but for now just I want to
receive raw signals.
 

How can I correct them?
Click to expand...

A radio frequency receiver is comprised of several circuits, each one doing its own task:
https://en.wikipedia.org/wiki/Radio_receiver_design

For each one you have to calculate component values according to specification you want to achieve. Your circuit barely seems to have all parts as shown at the above link, therefore rather than corret your circuit, you should redesign instead of copy-paste circuit from somewhere without knowing exactly what they do.
 

andre_teprom said:
A radio frequency receiver is comprised of several circuits, each one doing its own task:
https://en.wikipedia.org/wiki/Radio_receiver_design

For each one you have to calculate component values according to specification you want to achieve. Your circuit barely seems to have all parts as shown at the above link, therefore rather than corret your circuit, you should redesign instead of copy-paste circuit from somewhere without knowing exactly what they do.
Click to expand...

I don't agree with you, I think I can correct it, so I must correct it myself, actually it is correct!!!, I think just I have to find better parts, If I change components and add new values it's redesign.
 

A receiver that "receives many frequencies at the same time"
is a lousy receiver, in terms of selectivity - if you want to
listen to -a- frequency, what you want will be buried in "noise"
(true broadband ambient noise plus all interferers).

The uses for such a circuit are few (like, "detect any local
low frequency RF", which is occasionally but rarely useful).
 

Really no one knows better audio amp model:roll:?!!!

You was right:

nn.PNG
 

000SHREDDER000 said:
I want to simply receive them without tuning and demodulating
Click to expand...

1.
It is possible to receive magnetic or electromagnetic transmissions in the audio range, and listen to them without demodulating. You only need to amplify what comes from the antenna. (The antenna needs to be large.) Noises originate from atmospheric phenomena, lightning, whistlers, etc.

2.
Ambient mains hum emanates from house wiring and appliances. If you figure out a way to create a good wireless coupling to it, then you might have a source of energy harvesting.

3.
Your radio AM band probably has one or two strong local stations. Anyone can build an old-fashioned 'crystal' radio receiver, which needs no power. A homemade tuning coil and capacitor tends to have low selectivity, so you might hear two or more stations simultaneously.
 

BradtheRad said:
1.
It is possible to receive magnetic or electromagnetic transmissions in the audio range, and listen to them without demodulating. You only need to amplify what comes from the antenna. (The antenna needs to be large.) Noises originate from atmospheric phenomena, lightning, whistlers, etc.

2.
Ambient mains hum emanates from house wiring and appliances. If you figure out a way to create a good wireless coupling to it, then you might have a source of energy harvesting.

3.
Your radio AM band probably has one or two strong local stations. Anyone can build an old-fashioned 'crystal' radio receiver, which needs no power. A homemade tuning coil and capacitor tends to have low selectivity, so you might hear two or more stations simultaneously.
Click to expand...

Man it's an All Band Receiver not a simple crystal radio!, I don't want a giant antenna.
 

000SHREDDER000 said:
Man it's an All Band Receiver not a simple crystal radio!
Click to expand...

Aside from the controversial blog mentioned above, I did not find anywhere an amazing "all-band" receiver. Actually, there are ICs which do that, but these have standard AM/FM receivers built in, so there are a clear misuse in the terminology from your side, diverging from the conventional.

The closest of an "all-band" receiver which we could recognize is what was formerly known as a galena crystal receiver, which in other words had no intermediate frequency, but even this circuit does not look like the one that you insist that works, therefore I recommend you claim the patent of the above discovery, but first you should prove that it works, at least in simulation.
 

andre_teprom said:
Aside from the controversial blog mentioned above, I did not find anywhere an amazing "all-band" receiver. Actually, there are ICs which do that, but these have standard AM/FM receivers built in, so there are a clear misuse in the terminology from your side, diverging from the conventional.

The closest of an "all-band" receiver which we could recognize is what was formerly known as a galena crystal receiver, which in other words had no intermediate frequency, but even this circuit does not look like the one that you insist that works, therefore I recommend you claim the patent of the above discovery, but first you should prove that it works, at least in simulation.
Click to expand...

I know and you know what I said, it isn't but my mean was it must be an all band receiver, it can detect around AM band but no one said how can I improve it for detecting higher frequencies I don't think it's a rally hard question!
If you say it's impossible then I quit.
here is a car version of it I think it's better, can I modify it to portable 9v version?
car version.PNG
 
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