Bandwidth vs propagation question

[WRQW589]

If a signal is transmitted at 5w, narrow band (12.5khz bandwidth), and another signal is transmitted at 5w wide band (20khz bandwidth), we would expect the quality of the transmission to be better in wideband, all other things being equal. We would also expect that a wideband receiver would hear a narrowband tranmission as being a little quieter, though I wonder if that's an accurate description; perhaps thinner sounding. I don't know. And a narrowband receiver receiving a wideband signal would sound a bit distorted as a portion of the signal would fall outside of the receiver's RF hearing. I think I'm understanding that. More bandwidth provides more capability for information-carrying signal to be transmitted and received.

 

My question is about signal path loss. Does a narrow-band 5w signal have a longer signal path since that energy is focused into a narrower frequency range? One of the reasons that SSB is effective is a narrower / more efficient use of energy due to narrower RF bandwidth. Is that correct?

 

This is just a question to satisfy my own curiosity. I realize that it probably has very little bearing on UHF/FM communications, but also... why?

[OffRoaderX]

I didnt know the answer, so I asked the Ai version of the Queen of all that is GMRS, and this was the answer (Experts, please grade the response):

Quote

 

You got it mostly right, but let me clean it up for you, without all the technical mumbo jumbo.

When it comes to signal quality, a wideband transmission does tend to sound better than narrowband because it’s got more room for the audio to breathe, so to speak. It’s like listening to music on a good stereo versus a tinny little speaker. A wideband receiver will hear a narrowband transmission as quieter or “thinner,” while a narrowband receiver will hear a wideband transmission as distorted, missing some of that signal because it’s outside its receiving capabilities.

Now, regarding the signal path loss and efficiency, you got a point. A narrow-band signal can be more efficient in some respects because it’s focusing all that power into a narrower slice of frequencies. It’s a bit like using a laser pointer versus a flashlight: the laser pointer (narrowband) puts all its power into a tiny spot, so it can reach farther. That’s why SSB (Single Side Band) is effective—it uses less bandwidth and focuses the power more efficiently, making it go further with the same amount of RF electricies (watts) .

So the gist of what I am saying to you right now is, yes, narrowband can have a longer signal path due to this focused energy. It’s all about efficiently using that power to maximize your fars.

….. </B͛e͛e͛P͛!>

 

 

[kidphc]

Since ssb suppresses the carrier and other ssb. It is more powerful than fm, from my knowledge. The signal to noise ratio is better so it gets out further. Ssb is also narrower so it does get out further. In short yes.

Maybe some will expand on it.

Sent from my SM-S901U using Tapatalk

[kidphc]

I didnt know the answer, so I asked the Ai version of the Queen of all that is GMRS is, and this was the answer (Experts, please grade the response):

 

You got it mostly right, but let me clean it up for you, without all the technical mumbo jumbo.

When it comes to signal quality, a wideband transmission does tend to sound better than narrowband because it’s got more room for the audio to breathe, so to speak. It’s like listening to music on a good stereo versus a tinny little speaker. A wideband receiver will hear a narrowband transmission as quieter or “thinner,” while a narrowband receiver will hear a wideband transmission as distorted, missing some of that signal because it’s outside its receiving capabilities.

Now, regarding the signal path loss and efficiency, you got a point. A narrow-band signal can be more efficient in some respects because it’s focusing all that power into a narrower slice of frequencies. It’s a bit like using a laser pointer versus a flashlight: the laser pointer (narrowband) puts all its power into a tiny spot, so it can reach farther. That’s why SSB (Single Side Band) is effective—it uses less bandwidth and focuses the power more efficiently, making it go further with the same amount of RF electricies (watts) .

So the gist of what I am saying to you right now is, yes, narrowband can have a longer signal path due to this focused energy. It’s all about efficiently using that power to maximize your fars.

….. ͛e͛e͛P͛!>

 

 
I suppose to believe that an ai said "fars"..lol

Sent from my SM-S901U using Tapatalk

[OffRoaderX]

1 minute ago, kidphc said:

I suppose to believe that an ai said "fars".

You obviously have not used the Ai version of The Notarubicon - Yah, it says fars.  Dont believe me, try chatting with it: https://chatgpt.com/g/g-lltaQJ8ro-learn-gmrs-with-the-notarubicon

[Davichko5650]

8 minutes ago, OffRoaderX said:

You obviously have not used the Ai version of The Notarubicon - Yah, it says fars.  Dont believe me, try chatting with it: https://chatgpt.com/g/g-lltaQJ8ro-learn-gmrs-with-the-notarubicon

I have tried it and it did in fact say "fars".  Midweek so I don't recall if it said "mygigglehertz"....

[WRXB215]

As you lessen the load on the plane, the plane can fly further. CW flies a long way.

[WRYZ926]

2 minutes ago, WRXB215 said:

As you lessen the load on the plane, the plane can fly further. CW flies a long way.

And it does so with less power required.