Novice description of RF vs Electrical waves

[keithb1234]

Is there a simple explanation of the difference between RF waves, WiFi Signals, Bluetooth signals, electrical pulses, etc. In other words what is the difference if i create a wave by pulsing an electrical connection 50 times per second (50 hz), vs creating a 50hz sound wave. I need to create a 33Mhz RF signal and was wondering what is the difference between a 33Mhz RF signal and a 33Mhz tone generated from a computer/device?

Hopefully that makes sense.

 

[KlausST]

Hi,

What you bring up is a mixture of terms .. They may belong together, but not necessarily.

One could write a whole book to give feedback on your post, because your question is too corase .. and the answers could be very different dpending on what you focus on.

Just a tiny bit of an example:
waveform: It may be a pure sine. It is defined by amplitude and frequency. But there may also be a DC offset.
Or there may exist erroneous overtones, caused by distortion.
Or there are intentional overtones. If you use the right frequencies with the right amplitudes and the right phase alignment .. you may create a square wave ... or by using different amplitudes and phase shifts you may generate a triangle shape.

One could go even further into detail ... and still nothing mentioned about bandwidth, bursts, modulation, impedances, medium, voltage, current, and many other parameters....

So, please focus on one item (after the other) and ask a detailed question.

Klaus

 

[danadakk]

Generally speaking in the vernacular of the industry a tone is
considered audible sound, not RF.

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If you feed a 33 Mhz RF sine into a circuit, and it has no non linear elements in it,
then you get a sine out. Keep in mind all active amplifier circuits have some non
linearity in them. But well designed you get a sine out for this situation.

But if you feed a pulsed waveform into a circuit it inherently has strong harmonics
in its composition, so you get a pulsed waveform out, if circuit has enough BW to
handle the harmonics.


Regards. Dana.

 

[keithb1234]

Thanks - I am trying to figure out the differences between RF waves, EM waves, and Audio waves but don't know enough yet to phrase my question right. I did find a guide that might help me to clarify my question.

 

[volker@muehlhaus]

what is the difference between a 33Mhz RF signal and a 33Mhz tone generated from a computer/device?

There is no difference, if your computer output can generate that high frequency.

 

[FvM]

The question isn't completely clear, but sound waves are air pressure changes propagating in space, EM waves are propagating coupled electrical and magnetical fields.

Electrical signals can be converted into sound waves by sending it to a sound transducer or into EM waves by sending it to an antenna.

 

[keithb1234]

The question isn't completely clear, but sound waves are air pressure changes propagating in space, EM waves are propagating coupled electrical and magnetical fields.

Electrical signals can be converted into sound waves by sending it to a sound transducer or into EM waves by sending it to an antenna.

Ok - i get that sound is air pressure changes and EM are electrical/magnetic - but before the sound signal gets to a speaker it is EM and the speaker converts it to Air pressure right. What is the difference between the EM on the wire and an RF signal?

 

[FvM]

As stated, the question is unclear. A 33 MHz signal on a cable will be usually not described as electromagnetic wave but simply as AC voltage. For higher frequencies, propagation speed, cable impedance and possibly signal reflections become relevant and you may want to analyze the signal as (one-dimensional) wave.

EM waves in free space are generally three-dimensional and you can't analyze it's behavior without considering interaction of electrical and magnetically fields, in other words complete set of Maxwell equations.

 

[KlausST]

Hi,

Ok - i get that

not really. It is:
* electric signals <--> [antenna] <--> electromagnetic FIELDS
* electric signals --> [speaker] --> acoustic signals (air pressure)
* acoustic signals --> [microphone] --> electric signals

Electric signals need something electrically conductive. A copper wire for example.
EM fields don´t need anything. They can be transmitted even in vaccuum.
Acoustic signals need something. Air, liquids, solid material, but does not work in vaccuum

It´s still not clear what information you are after.

Give an example, tell us your ideas.

Klaus

 

[BradtheRad]

difference between the EM on the wire and an RF signal?

RF is photons traveling in air (or vacuum or 'ether') in the form of electromagnetic waves. Similar to microwaves, light, x-rays, etc.

RF transmitting circuits have a borderline condition where oscillations in the wiring attain the state of EM waves, emitting from the wiring or an antenna of some kind.

Here is a phenomenon which touches on all three terms. Surrounding our earth are VLF (very low frequency and very-long-wavelength) electromagnetic waves at audio frequencies. They are not audible sound waves. They're more like radio waves. Articles describe picking up these electromagnetic waves using large coils wrapped around the walls of a living room. A simple audio amplifier lets you listen to them. A sound often heard is called 'whistlers'.

They have directionality. Reports from experimenters claim the planet Jupiter has its variety of electromagnetic waves at audio frequencies. As with earth, these are not the same thing as sound waves. They travel through the vacuum of space as electromagnetic waves.

Electromagnetism is not the same thing as magnetism.
Electromagnetism is not the same thing as an electromagnet.

 

[keithb1234]

Hi,


not really. It is:
* electric signals <--> [antenna] <--> electromagnetic FIELDS
* electric signals --> [speaker] --> acoustic signals (air pressure)
* acoustic signals --> [microphone] --> electric signals

Electric signals need something electrically conductive. A copper wire for example.
EM fields don´t need anything. They can be transmitted even in vaccuum.
Acoustic signals need something. Air, liquids, solid material, but does not work in vaccuum

It´s still not clear what information you are after.

Give an example, tell us your ideas.

Klaus

Actually that helps. I am confusing a pulsed electrical signal with an electromagnetic field. I will try and refine my question and give an example in a couple days. I am taking off for the weekend.

 

[D.A.(Tony)Stewart]

Ask AI or Look up: Fourier spectrum of a pulse in amplitude and phase of harmonics.
Also ask how does Er = dielectric constant of the insulator change the speed of conducted vs radiated waves.

 

[keithb1234]

Thanks everyone - so what i am understanding is that an electrical pulse is the same until it gets to a transceiver. The transceiver converts it into audio, rf, whatever. Depending on the transmitter it can be 2.4Ghz or 5Ghz or some other frequency. The only difference between like Bluetooth, WiFI, cellular is the frequency of the signal, based on the transmitter. They are all forms of RF waves.

 

[keithb1234]

Hi,


not really. It is:
* electric signals <--> [antenna] <--> electromagnetic FIELDS
* electric signals --> [speaker] --> acoustic signals (air pressure)
* acoustic signals --> [microphone] --> electric signals

Electric signals need something electrically conductive. A copper wire for example.
EM fields don´t need anything. They can be transmitted even in vaccuum.
Acoustic signals need something. Air, liquids, solid material, but does not work in vaccuum

It´s still not clear what information you are after.

Give an example, tell us your ideas.

Klaus

So, what i am trying to do is replicate a device built by Raymond Rife in the 30s. It produced a 3.3Mhz RF signal modified with an audio signal. I am trying to reproduce the signal using an Arduino and some sort of transmitter, i guess. I can post links to the original work, but the documentation is sparse and hard to weed through.

 

[KlausST]

Hi,

Rather confusing:
* frequencies: 50Hz, 33MHz, 2.4GHz, 5.0GHz, now 3.3MHz

Now you talk about modulation. And you talk about some interfaces like WiFi and BT and Raymond Rife´s device.
(Please, when you refer to such informations, post a link, so we can look it up)
There are several types of modualtion:
To name a couple: AM, FM, PSK, QUAM ... some are good for analog signals, some are for digital signals.

WiFi and BT are for digital data transfer. I bet Raymond Rife´s machine was for analog signals.

***
Then you talk about Arduino. The next riddle. Arduino is an IDE and Arduino is some kind of "hardware standard" for boards to be programmed via the Arduino IDE. Different boards use different microcontrollers with different features. Thus the word "Arduino" tells us about nothing.

***
Then I guess you mixed TRANSCEIVER with TRANSMITTER. A transceiver is the combination of transmitter and receiver.
From all your informations before I can´t find that you want to build a device to "receive". Correct me if I´m wrong.

***
The problem is: your post are very diffuse. I can´t find what information you are after. You (randomly) mix phrases ...

A forum can´t replace school. I recommend you to:
* draw a sketch of what you want to achieve .. your target function.
* then do internet search on your own.
* if you fail to understand some items ... first do internet investigation. Maybe use chatGPT.
* if still are doubts: Give a link to the according document and ask a detailed question .. by referring to the document (chapter / page..)

Klaus

 

[keithb1234]

Hi,

Rather confusing:
* frequencies: 50Hz, 33MHz, 2.4GHz, 5.0GHz, now 3.3MHz

Now you talk about modulation. And you talk about some interfaces like WiFi and BT and Raymond Rife´s device.
(Please, when you refer to such informations, post a link, so we can look it up)
There are several types of modualtion:
To name a couple: AM, FM, PSK, QUAM ... some are good for analog signals, some are for digital signals.

WiFi and BT are for digital data transfer. I bet Raymond Rife´s machine was for analog signals.

***
Then you talk about Arduino. The next riddle. Arduino is an IDE and Arduino is some kind of "hardware standard" for boards to be programmed via the Arduino IDE. Different boards use different microcontrollers with different features. Thus the word "Arduino" tells us about nothing.

***
Then I guess you mixed TRANSCEIVER with TRANSMITTER. A transceiver is the combination of transmitter and receiver.
From all your informations before I can´t find that you want to build a device to "receive". Correct me if I´m wrong.

***
The problem is: your post are very diffuse. I can´t find what information you are after. You (randomly) mix phrases ...

A forum can´t replace school. I recommend you to:
* draw a sketch of what you want to achieve .. your target function.
* then do internet search on your own.
* if you fail to understand some items ... first do internet investigation. Maybe use chatGPT.
* if still are doubts: Give a link to the according document and ask a detailed question .. by referring to the document (chapter / page..)

Klaus

Do you get the feeling i really don't know what i am talking about? I have bits and pieces of what i know and am trying to string it together. I'm kind of like a kid who learned how to ride a bike and now wants to know how to drive a formula F1 car. I mean it is basically the same thing right (go fast, steer, brake, etc)?

To clarify a couple of things. I was using Arduino as a generic reference to ESP8266/ESP32 SOC boards that i am working with on other projects. I know Arduino is just the IDE but i get lazy and use it to refer to the boards.

I guess i used the wrong term for transceiver. I was thinking in computer networking terms of devices that change signals into different types (optical/electrical). You are correct in that i am really interested in just a transmitter.

I know a forum can't replace a school - You are being very patient in trying to guess what i am thinking. I have been doing searches but part of the problem is that i don't know enough to know what to search for. And when i find information, it is so far over my head i am lost. I honestly think that the whole RF/EM stuff is borderline magic.

The basic idea that i want to create is a device that generates a 3.3Mhz RF signal that is modified(?) with a signal between 200Khz and 1.6Mhz.

If you want to go down the rabbit hole here are a couple links

Royal Rife Technologies

Dr. Rife's True Original Frequencies

I really appreciate the time you have taken to respond to me.

 

[D.A.(Tony)Stewart]

The frequency can be a low-energy inert gas tube wand pulsed LC resonant circuit that tingles from the modulation. Some believe in certain patterns of pulsing.
The carrier frequency in this MHz range is irrelevant but preferably an AM channel for public use or does not exceed local guidelines for E-fields for example Canada
or US FCC .
I suggest 28MHz AM pulsed low frequency patterns

Absorption losses injected in tissue generally increase with frequency. Thus SAR reported W/kG is frequency sensitive.

I have seen one example of a Cat cured of cancer stg.3 by an inventor who used a glass wand filled with argon/helium pulsed at 28 MHz and a friend who had a multi-fluorescent tube floor unit that was an expensive duplicate of a Rife unit, that was ineffective.

Few websites report positive effects: https://www.healthline.com/health/rife-machine-cancer

https://www.scirp.org/journal/paperinformation?paperid=120483 Cancer-Specific Resonances

 

[D.A.(Tony)Stewart]

In the report it clearly states that the original Rife machine was rich in spurious harmonics which support my experience that the precise carrier frequency is unimportant and broadband harmonics or higher frequency operation is acceptable and better than sinusoidal 3 MHz.

"The building of this instrument also showed that it didn't have the reported harmonics which the genuine Beam Ray Clinical instrument was supposed to have. Little did we know, at that time, that the harmonic concept we were looking for was there but we didn’t really understand how the instrument was supposed to work."

 

[KlausST]

The basic idea that i want to create is a device that generates a 3.3Mhz RF signal that is modified(?) with a signal between 200Khz and 1.6M

No.
The true goal is something else. What do you expect the frequency to do?

Btw: modulating a 3.3MHz carrier frequency ... with a 16MHz signal ... does not work. (At least I think so. I'm no modulation specialist)
Again two new frequencies: 200kHz and 1.6MHz .... I see no progress.

I come back after you did some research and followed my recommendations of post#15.

Klaus

 

[keithb1234]

No.
The true goal is something else. What do you expect the frequency to do?

Btw: modulating a 3.3MHz carrier frequency ... with a 16MHz signal ... does not work. (At least I think so. I'm no modulation specialist)
Again two new frequencies: 200kHz and 1.6MHz .... I see no progress.

I come back after you did some research and followed my recommendations of post#15.

Klaus

The goal is to try and replicate the device. We do agricultural research at my work and one of the original frequencies was supposed to kill nematodes. I would like to see if it is possible to create a low cost, effective device that would do that. Beyond that it would be interesting to see if the concept is valid. To me it makes sense and seems plausible. I take a lot of the information on the web with a grain of salt, both for and against. I have a healthy distrust of the medical industry, especially when they say that a cheap, effective alternative is not good.

I will keep doing research though. It does make sense that modulating a 3.3Mhz carrier with a 16Mhz signal won't work. I will look more into how stuff about how modulation works on a carrier signal and see what other research i can find on the original device to see if it can be replicated.

Again - i thank you for all the time you have taken and the information you have provided. I know i have not been clear in what i am looking for, not intentionally, just out of ignorance.