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Digital Space Noise Detector

jamesadrian

Apr 4, 2023
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a) It doesn't matter what I would select. It's not my project and I have no operating parameters.

b) Since I have no idea what the intended application is, I have no idea.

After seven posts, we still have no idea what you are trying to achieve. We do not know if the white noise bit stream is going to the shift register's data input or clock input. If it is the data input, we do not know the clock frequency. The clock acts as a lowpass filter, significantly altering both the "whiteness" and the randomness of the result. This bears directly on the analog front end design.

Or, the white noise bit stream could be driving the clock input, to randomly (in the time domain) sample some other waveform for some other reason. All of this affects the required bandwidth of the noise source.

Three days, seven posts - not one number.

ak
AnalogKid,

I wish to make a product that converts the noise from space into binary digits stored in a flash drive. I am looking for people who have experience designing circuits of the kind that can implement the analog part of the product.
 

hevans1944

Hop - AC8NS
Jun 21, 2012
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No known algorithm is truly random.
This is true, but a finite-sized flash drive cannot hold a truly random set of bits either. Try generating, in binary, the number pi, which is approximately 3, to a few hundred-thousand or so bits and then take any sequential set from that series, enough to fill up your flash drive. That set won't be truly random either, but it may be "random enough" for many purposes, none of which you have specified. RF noise sources may generate random amplitudes, with a frequency spectrum approaching randomness, but unless the "RF noise source" has a frequency spectrum that extends from DC to infinity, it can not be a truly random noise source... even if the "noise" comes from a star.
 

hevans1944

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Concerning the adjusting of the range of input frequencies, you all may be interested in this link:



James Adrian
The "mixing" of two (or more) sine waves of different frequencies to create sum and difference frequency components is a well-known phenomenon. It is called heterodyning. It only occurs if the "mixing" is performed with a non-linear device, such as a human ear which has a logarithmic response. In electronics, mixing occurs when one signal is modulated by another signal. This can be modulation of amplitude, frequency, or phase and the result is the production of sideband frequencies. For amplitude modulation, there are two sidebands equally spaced above and below the frequency of the signal (called the carrier) that is modulated.

For frequency and phase modulations the sidebands are similar, but are described by more complicated functions and the sidebands are repetitive and theoretically infinite. However, that is not the topic under discussion. In this context, modulation means to vary some characteristic of a signal, such as its amplitude, frequency or phase as a function of some other signal, which may also vary in amplitude, frequency or phase.

Linear processing of two (or more) sine waves DOES NOT result in the production of sum and difference frequencies. The term "high fidelity" was applied originally to very linear audio amplification because "hi-fi" devices did not deliberately produce sum and difference frequencies from the audio input. That is, hi-fi tried to produce an output that was faithful in reproduction of the input, without adding or subtracting anything, or creating new frequency components sounds not present in the original. The same applies to RF: linear amplifiers are used to avoid the production of sum and difference frequencies or intermodulation distortion.

What any of this sum and difference frequency stuff has to do with generating truly random numbers from outer space is a mystery to me. As I may have mentioned before, any number from a set of finite numbers stored in any sort of finite memory device, such as a flash drive, is NOT a random number. It is simply a member of a finite set of numbers, however derived from a set of infinite possibilities. In other words, trying to squeeze random numbers (space noise) into a finite-sized box destroys the randomness by making it specifically finite. The probability of any number stored in the flash drive being truly random is exactly zero.

Are you ever going to tell us what you are trying to do? No one here is going to design your "analog" front end without knowing what it is supposed to do, or how it is supposed to do it. One of our moderators, @davenn, is quite well-versed in microwave electronics. Perhaps you should send him a private message explaining what you are trying to do, and WHY you are trying to do it, instead of wasting our time here in the forums.

Hop - AC8NS

BTW: I LOVE your website!
 
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jamesadrian

Apr 4, 2023
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The "mixing" of two (or more) sine waves of different frequencies to create sum and difference frequency components is a well-known phenomenon. It is called heterodyning. It only occurs if the "mixing" is performed with a non-linear device, such as a human ear which has a logarithmic response. In electronics, mixing occurs when one signal is modulated by another signal. This can be modulation of amplitude, frequency, or phase and the result is the production of sideband frequencies. For amplitude modulation, there are two sidebands equally spaced above and below the frequency of the signal (called the carrier) that is modulated.

For frequency and phase modulations the sidebands are similar, but are described by more complicated functions and the sidebands are repetitive and theoretically infinite. However, that is not the topic under discussion. In this context, modulation means to vary some characteristic of a signal, such as its amplitude, frequency or phase as a function of some other signal, which may also vary in amplitude, frequency or phase.

Linear processing of two (or more) sine waves DOES NOT result in the production of sum and difference frequencies. The term "high fidelity" was applied originally to very linear audio amplification because "hi-fi" devices did not deliberately produce sum and difference frequencies from the audio input. That is, hi-fi tried to produce an output that was faithful in reproduction of the input, without adding or subtracting anything, or creating new frequency components sounds not present in the original. The same applies to RF: linear amplifiers are used to avoid the production of sum and difference frequencies or intermodulation distortion.

What any of this sum and difference frequency stuff has to do with generating truly random numbers from outer space is a mystery to me. As I may have mentioned before, any number from a set of finite numbers stored in any sort of finite memory device, such as a flash drive, is NOT a random number. It is simply a member of a finite set of numbers, however derived from a set of infinite possibilities. In other words, trying to squeeze random numbers (space noise) into a finite-sized box destroys the randomness by making it specifically finite. The probability of any number stored in the flash drive being truly random is exactly zero.

Are you ever going to tell us what you are trying to do? No one here is going to design your "analog" front end without knowing what it is supposed to do, or how it is supposed to do it. One of our moderators, @davenn, is quite well-versed in microwave electronics. Perhaps you should send him a private message explaining what you are trying to do, and WHY you are trying to do it, instead of wasting our time here in the forums.

Hop - AC8NS

BTW: I LOVE your website!

hevans1944,​

I wish to provide numbers to scientists who wish to make their experiments unbiased. One idea is to use the noise from space. No finite collection of 1s and 0s is absolutely random, according to many definitions. Noise from space at least creates great uncertainty. There is no human interference, if you can avoid radio stations. The need for these numbers is well established and continuing.

A circuit that amplifies in a sufficiently non-linear way is one of the several challenges.

Creating a product needs to start somewhere. You know a lot about this. I hope you no longer feel my questions may be waisting your time.

Very sincerely,

James Adrian


P.S. By the way, I was born in 1944.
 
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jamesadrian

Apr 4, 2023
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The "mixing" of two (or more) sine waves of different frequencies to create sum and difference frequency components is a well-known phenomenon. It is called heterodyning. It only occurs if the "mixing" is performed with a non-linear device, such as a human ear which has a logarithmic response. In electronics, mixing occurs when one signal is modulated by another signal. This can be modulation of amplitude, frequency, or phase and the result is the production of sideband frequencies. For amplitude modulation, there are two sidebands equally spaced above and below the frequency of the signal (called the carrier) that is modulated.

For frequency and phase modulations the sidebands are similar, but are described by more complicated functions and the sidebands are repetitive and theoretically infinite. However, that is not the topic under discussion. In this context, modulation means to vary some characteristic of a signal, such as its amplitude, frequency or phase as a function of some other signal, which may also vary in amplitude, frequency or phase.

Linear processing of two (or more) sine waves DOES NOT result in the production of sum and difference frequencies. The term "high fidelity" was applied originally to very linear audio amplification because "hi-fi" devices did not deliberately produce sum and difference frequencies from the audio input. That is, hi-fi tried to produce an output that was faithful in reproduction of the input, without adding or subtracting anything, or creating new frequency components sounds not present in the original. The same applies to RF: linear amplifiers are used to avoid the production of sum and difference frequencies or intermodulation distortion.

What any of this sum and difference frequency stuff has to do with generating truly random numbers from outer space is a mystery to me. As I may have mentioned before, any number from a set of finite numbers stored in any sort of finite memory device, such as a flash drive, is NOT a random number. It is simply a member of a finite set of numbers, however derived from a set of infinite possibilities. In other words, trying to squeeze random numbers (space noise) into a finite-sized box destroys the randomness by making it specifically finite. The probability of any number stored in the flash drive being truly random is exactly zero.

Are you ever going to tell us what you are trying to do? No one here is going to design your "analog" front end without knowing what it is supposed to do, or how it is supposed to do it. One of our moderators, @davenn, is quite well-versed in microwave electronics. Perhaps you should send him a private message explaining what you are trying to do, and WHY you are trying to do it, instead of wasting our time here in the forums.

Hop - AC8NS

BTW: I LOVE your website!
Thank you for looking at my website. It has been up for 32 years.

James Adrian
 

Delta Prime

Jul 29, 2020
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It is called heterodyning. It only occurs if the "mixing" is performed with a non-linear device, such as a human ear which has a logarithmic response.
Not so.
The very reason we choose the
superheterodyne architecture is to simplify the filtering problems.
It’s much easier to filter a fixed IF
than filter a variable RF.
an local oscillator with a fixed amplitude sinusoid is applied to the mixer & mixers can be realized
with either time-varying circuits or non-linear circuits.
James Adrian
You should have said.
This is concerning the science of information theory and I wish to incorporate Galactic background radiation into a binary noise
 channel to model error correction.
But then again as the moderators graciously pointed out and it's true. I may have this new interpretation totally wrong as well.
 

Delta Prime

Jul 29, 2020
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Heck if I know.I just see everybody else putting OP.
I'm pretty much just a lemming.
I think for the person who started the thread I should have said thread starter TS. But I really don't know.
.
 

Harald Kapp

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I wish to make a product that converts the noise from space into binary digits stored in a flash drive.
What's the use of this?
I'm not a crypto expert, but I've read some about cryptography. From my understanding you can use the FLASH drive only once in a secure manner. The second time you use it, the numbers are no longer random (see one time pad). Re-using the same set of "random" numbers opens any crypto scheme to attack.

Have you had a look at Intel's random number generator in the IS64 cpu architecture? You can even these even from a programming language as simple as Python.
There's also more than one internet service that claims to offer true random numbers from athmospheric noise or a multiplicity of sources.
 

jamesadrian

Apr 4, 2023
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What's the use of this?
I'm not a crypto expert, but I've read some about cryptography. From my understanding you can use the FLASH drive only once in a secure manner. The second time you use it, the numbers are no longer random (see one time pad). Re-using the same set of "random" numbers opens any crypto scheme to attack.

Have you had a look at Intel's random number generator in the IS64 cpu architecture? You can even these even from a programming language as simple as Python.
There's also more than one internet service that claims to offer true random numbers from athmospheric noise or a multiplicity of sources.
This is not for encryption. As I have said, it is for scientific experiments where arbitrary selections must be made without human bias. It is a persistent and continuing need. You might read actual experiments, particularly those involving groups of people. The more random the selections, the less doubt.

James Adrian
 

jamesadrian

Apr 4, 2023
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Apparently, no search engine provides any relevant articles in response to "How to make a non-linear amplifier."
Does anybody here know how to make just a non-linear amplifier, in isolation of everything else - to show how it is done? All the search engines I have tried only talk about how to eliminate non-linearity.

James Adrian
 
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AnalogKid

Jun 10, 2015
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OP stands for Original Poster. Some forums prefer TS for Thread Starter.

ak
 

Harald Kapp

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This is not for encryption. As I have said, it is for scientific experiments where arbitrary selections must be made without human bias.
I think my argument is still valid: Once you re-use the data from the FLASH you get the same random number sequence. Therefore what you are looking for is imho a true random number generator which can be found e.g. by using the links I provided.

Although consider a good pseudo random number generator (PNRG) will deliver random number sufficiently random and definitely not human-biased for scientific experiments. Especially once you seed the PNRG with a different seed (e.g. unix time) every time you generate a sequence.

Apparently, no search engine provides any relevant articles in response to "How to make a non-linear amplifier."
Mine does. The term "non-linear amplifier" is very general. what exacrtly do you need? You could use a clipping amplifier which is linear in a part of its range but clips and is therefore non-linear in another part of its range. Or you could use a log-amplifier with a logarithmic characteristic.
How does your quest for a non-linear amplifier fit into the question of generating random numbers?
 

jamesadrian

Apr 4, 2023
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I think my argument is still valid: Once you re-use the data from the FLASH you get the same random number sequence. Therefore what you are looking for is imho a true random number generator which can be found e.g. by using the links I provided.

Although consider a good pseudo random number generator (PNRG) will deliver random number sufficiently random and definitely not human-biased for scientific experiments. Especially once you seed the PNRG with a different seed (e.g. unix time) every time you generate a sequence.


Mine does. The term "non-linear amplifier" is very general. what exacrtly do you need? You could use a clipping amplifier which is linear in a part of its range but clips and is therefore non-linear in another part of its range. Or you could use a log-amplifier with a logarithmic characteristic.
How does your quest for a non-linear amplifier fit into the question of generating random numbers?
A non-linear amplifier is needed to lower the range of frequencies of the space noise by mixing it with a sign wave from a local oscillator.

James Adrian
 

hevans1944

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This is not for encryption. As I have said, it is for scientific experiments where arbitrary selections must be made without human bias. It is a persistent and continuing need. You might read actual experiments, particularly those involving groups of people. The more random the selections, the less doubt.

James Adrian
Thank you for that response. There are statistical tests that can be performed to determine if a large sequence of "random" numbers meets some definition of randomness (there are several definitions currently in use). So, if you want to build and market a commercial device, you need to determine which statistical test will satisfy your potential customers. That it turn will help define how you create a set of working "random" numbers you can write into a flash memory.

Many things, other than noise from outer space, generate random events. One characteristic of true random noise is it exhibits a flat frequency spectrum from zero to infinity, which our ears interpret as "white noise." Of course our ears are limited in frequency response, so the white noise you think you hear is actually not. If you use real components, the frequency spectrum will be truncated, and the frequency spectrum low and high end-points will be "rounded off" as a characteristic of the device generating "random" numbers.

There are many electronic devices that exhibit randomness. Ordinary resistors, operating at temperatures greater than absolute zero, create Johnson noise because of the thermal motion of charge carriers (electrons). Perhaps you can use a resistor as a noise source to generate random numbers.

Getting noise signals from space, uncorrupted by man-made signals from satellites in Earth orbit, is difficult and getting worse. There is a lot of stuff up there generating RF signals. You need to build a radio-telescope antenna with a very narrow beam width (large dish) and point it at a "quiet" portion of the sky. Or perhaps use our sun as your noise source. Radio astronomers go to great lengths to remove noise from the signals they study. It is not unheard of to cool the low-noise amplifier, mounted at the antenna feed, either with a cryogenic liquid (nitrogen) or with a Peltier heat pump. Operating in a cold climate would help too.
 

melvinlcotto

Mar 29, 2023
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With the use of a digital space noise detector, sources of undesired noise may be found and appropriate noise control measures can be applied. A digital space noise detector detects and evaluates sound levels in an area or space.
 
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