• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Infinite bandwidth, FM & the human voice?

LeapFrog

Wielding Hanlon's Razor
Feb 15, 2016
1,709
903
123
Anchorage, Alaska
jpbajdV.png

Here is a link to the "Reddit thread" I found while browsing that site.
[Click "Load More Comments"]

How does Gaussian function relate to "infinite time domain"?
How can I use the Bessel function?
What is this on about?
I don't understand the phrase "All finite time signals take infinite bandwidth".

What is meant by "the number of frequencies in human voice is infinite"?


also

I was born and raised on a small goat farm so of course I managed to brought this huge post full circle all the way back to crappy CB mods. (y) ( I don't quite think I'm ready for college-level quantum physics discussions )
A lot of theory is discussed in that thread, but how does this relate to a clean sine wave signal vs. flat topping in A.M.?
 
Last edited:

How does Gaussian function relate to infinite time domain & what is this on about? I don't understand the phrase "All finite time signals take infinite bandwidth.

A lot of theory is discussed in that thread, how does this relate to a clean sine wave signal vs. flat topping?

Dude, how could you do that to us? Quantum Mechanics? Plus a whole bunch of hyperbole I am trying to put into meaningful communications. Where is Schrodinger's cat?
 
Dude, how could you do that to us? Quantum Mechanics? Plus a whole bunch of hyperbole I am trying to put into meaningful communications.
*face palm*
My bad, it's probably years worth of theory to discuss, yikes!!
I guess if I'm trying to get a taste of what college level discussion would be, I don't know anything about the questions I asked, and to be honest I may not understand an honest answer unless it was simplified.


The quotation below is taken from here.
Where does "RF Signal" fall in these categories?
A signal can be classified based on its power or energy content. Signals having finite energy are energy signals. Power signals have finite and non-zero power.

Energy Signal :
A finite energy signal will have zero TOTAL power. Let’s investigate this statement in detail. When the energy is finite, the total power will be zero. Check out the denominator in the equation for calculating the total power. When the limit [imgbroken/img]∞

, the energy dilutes to zero over the infinite duration and hence the total power becomes zero.

Power Signal:
Signals whose total power is finite and non-zero. The energy of the power signal will be infinite. Example: Periodic sequences like sinusoid. A sinusoidal signal has finite, non-zero power but infinite energy.

A signal cannot be both an energy signal and a power signal.

Neither an Energy signal nor a Power signal:
Signals can also be a cat on the wall – neither an energy signal nor a power signal. Consider a signal of increasing amplitude defined by: [imgbroken/img]


For such a signal, both the energy and power will be infinite. Thus, it cannot be classified either as an energy signal or as a power signal.
Maybe one day I can bury my head in theory, for now I'll just enjoy talking on the radio.
 
Last edited:
  • Like
Reactions: Tallman
I cannot post what all I'm thinking at this point because I'm sure some "Arm Chair Physicist" will take offense. This is what it looks like when it is very very dark where your head is. And I'm not talking about you either LeapFrog.
After all he is looking for Schrodinger's cat.
Cage driver.jpg
 
the 88 MHz to 108 MHz is referring to the commercial FM broadcasting. It does have a huge bandwidth because of the stereo sub carriers 19 kHz and 38 kHz if I remember correctly. Add all of that plus the baseband audio and it gets wide.
Also the size of the signal and it's content is open to a lot of interpretation.
In Texas for example the size of the signal could refer to the caliber of the bullet and the intent of the person with the finger on the trigger.
 
  • Like
Reactions: LeapFrog
I cannot post what all I'm thinking at this point because I'm sure some "Arm Chair Physicist" will take offense. This is what it looks like when it is very very dark where your head is. And I'm not talking about you either LeapFrog.
After all he is looking for Schrodinger's cat.
View attachment 20013
Tallman, while I appreciate your strong stance, & firm approach on the subject of "Arm Chair Physicist", whomever this person is they have not yet showed up to make any outlandish claims in this thread.

I suggest people read scientific literature published in regards to the subject in debate, whatever that subject matter is...

Things may not be open for debate or interpretation, if someone gets offended because they have a different interpretation of the material; That is on them, what is fact is fact. How can someone "read a paper" & then emotionaly respond in regards to "how you read it", some miscommunication is happening on a deep level, where are the facts?

Someone needs to preemptively declare the FACTS of the situation and settle any potentional debates/retorts with knowledge.
Dancing around (& behind) an interpretation tells me someone believes they understand the material & is arguing that they know the facts and that you've got it wrong. Someone here is in error.
 
Last edited:
  • Like
Reactions: Tallman
the 88 MHz to 108 MHz is referring to the commercial FM broadcasting. It does have a huge bandwidth because of the stereo sub carriers 19 kHz and 38 kHz if I remember correctly. Add all of that plus the baseband audio and it gets wide.
Also the size of the signal and it's content is open to a lot of interpretation.
In Texas for example the size of the signal could refer to the caliber of the bullet and the intent of the person with the finger on the trigger.
The Reddit thread had the title: "Why are FM radio frequencies always listed with odd decimals (.1, .3, .5 etc instead of .2, .4, .6)?"
An answer for that question was provided in this LINK, shared by a Reddit user.
While perplexing, I found the "infinite bandwidth, & theory" discussion in the comments section more interesting!
 
Last edited:
Dude, how could you do that to us? Quantum Mechanics? Plus a whole bunch of hyperbole I am trying to put into meaningful communications. Where is Schrodinger's cat?
Ate the Cesium atom and the poison.
Scratched a hole from inside the box, got out, and then yakked it all up on the carpet - along with a hairball. Had to clean up a coil of super position as well.
 
Last edited:
The Reddit thread had the title: "Why are FM radio frequencies always listed with odd decimals (.1, .3, .5 etc instead of .2, .4, .6)?"
An answer for that question was provided here by a Reddit user.
While perplexing, I found the "infinite bandwidth" & theory discussion in the comments section more interesting!
The FCC sets a block of frequencies for certain uses and the bandwidth of the FM Stereo signal is around 250 kHz. Then you have to have 300 kHz separation between stations. So from 108 MHz 107.7 is the next available channel.
 
  • Like
Reactions: LeapFrog
The FCC sets a block of frequencies for certain uses and the bandwidth of the FM Stereo signal is around 250 kHz. Then you have to have 300 kHz separation between stations. So from 108 MHz 107.7 is the next available channel.
(y)
FCC Link here, it was in my previous post, but I couldn't make the link blue, also I often have issues creating a link on the forum software. (potential bug?)
 
Last edited:
...

The quotation below is taken from here.
, the energy dilutes to zero over the infinite duration and hence the total power becomes zero.



.

Absolutely incorrect.
P(ave) may approach zero, but it will never reach zero.

FWIW. even Algebra I students know better than to divide by or into zero.
 
  • Like
Reactions: LeapFrog

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Wildcat27:
    Hello I have a old school 2950 receives great on all modes and transmits great on AM but no transmit on SSB. Does anyone have any idea?
  • @ ButtFuzz:
    Good evening from Sunny Salem! What’s shaking?
  • dxBot:
    63Sprint has left the room.