Are these marine channels am or fm

[kmacka]

I'm trying to find out if these marine channels are am or fm, couldnt find an answer.

156.4500 Marine 9
156.6000 Marine 12
156.8000 Marine 16 Emerg.
157.0500 Marine 21A
157.1000 Marine 22A
157.1500 Marine 23A
156.4250 Marine 68
156.4750 Marine 69
157.0750 Marine 81A
157.1250 Marine 82A
157.1750 Marine 83A

 

[aensr]

All of the VHF Marine channels are NBFM
Alan

 

[kmacka]

All of the VHF Marine channels are NBFM
Alan

Thank you very much.

 

[Grog]

All of the VHF Marine channels are NBFM
Alan

I'm not monitoring USCG stuff anymore, but when did they switch to narrowband? What about all the old VHF radios out there?

 

[N_Jay]

I'm not monitoring USCG stuff anymore, but when did they switch to narrowband? What about all the old VHF radios out there?

They are 25 kHz NBFM, not the "new" 12.5 kHz narrowbanded FM.

 

[Grog]

They are 25 kHz NBFM, not the "new" 12.5 kHz narrowbanded FM.

I expected that, just was not sure as there are different views on just how "narrow" narrow really is :lol: I guess compaired to FM or TV a lot is narrowband.

 

[N_Jay]

Narrow and Wide FM are technical distinctions based n the modulation index of above or below "1".

http://en.wikipedia.org/wiki/Frequency_modulation

 

[WA4MJF]

Well, for years in Part 80, 90, etc wideband was 36F3 and narrowband was
16F3. Now 16F3 is wideband .

 

[N_Jay]

Well, for years in Part 80, 90, etc wideband was 36F3 and narrowband was
16F3. Now 16F3 is wideband .

Only by common usage. The technical definition stands.

 

[kb2vxa]

The occupied bandwidth of a standard FM communications channel is 10Khz (deviation +/- 5KHz) and NFM is 5KHz (deviation +/- 2.5KHz). That's the simple way of stating it, modulation index takes into account deviation, the highest modulating frequency and amplitude.

N_Jay likes to confuse people with stuff like that even when he himself is confusing bandwidth with channel spacing. I guess things like that happen when he uses a Wiki instead of FCC/ITU definitions.

Hmmm, if you remember the juice commercial on TV could be he needs "the V-8 forehead slap treatment". (;->)

 

[N_Jay]

The occupied bandwidth of a standard FM communications channel is 10Khz (deviation +/- 5KHz) and NFM is 5KHz (deviation +/- 2.5KHz).

Yet again, you have taken the time to prove you know much less than you think you know!

Occupied bandwidth includes the amount of the carrier shift, and the significant sidebands.

To put it in simple terms so you are not confused; "You are wrong!"

That's the simple way of stating it, modulation index takes into account deviation, the highest modulating frequency and amplitude.

Why yes, it does, and these are what define the spectral width of the signal. And that provides the true definition between wideband FM and narrowband FM. (Hence where we started.)

N_Jay likes to confuse people with stuff like that even when he himself is confusing bandwidth with channel spacing.

Excuse me?
I provided a clear and correct answer.
You in turn tried to "correct" me with WRONG information, confusing anyone who might not recognize your erroneous crap.
As for channel spacing, it was not brought up, although in Land Mobile communications, channel spacing and occupied bandwidth are often use in a manner as if they were the same.

If you pay attention to teh flow of the thread, you would see that as specific questions are raised, they were addressed in a clear and non-confusing manner. (Right up to when you decided to make a point of your (egotistically though to be) superior knowledge, and proceeded to post incorrect information addressing issues that no one was asking about.

I guess things like that happen when he uses a Wiki instead of FCC/ITU definitions.

No I used WIKI as a reference for others who might want to do some additional study.

I used my BSEE, FCC General Class Radiotelephone License, my 30+ yeas of experience in radio, including FM Broadcast, Land Mobile, Cellular, terrestrial microwave, and amateur as my reference.

You obviously need to go back to my WIKI reference and follow some of the links till you understand everything you think you know.

Hmmm, if you remember the juice commercial on TV could be he needs "the V-8 forehead slap treatment". (;->)

Yes, you do need that!

And here it is for you! (Read my Sig line):twisted:

P.S. If anyone would like to discuss channel spacing and occupied bandwidth, as it applies to the narrowbanding of frequencies below 512 MHz (The current narrowbanding activities), I would suggest so pre-work on emission masks and adjacent channel rejection ratios for various modulation forms (and the complete ignoring of anything Warren tries to add to the conversation).

 

[mciupa]

if anyone would like to discuss channel spacing and occupied bandwidth, as it applies to the narrowbanding of frequencies below 512 MHz (The current narrowbanding activities), I would suggest some pre-work on emission masks and adjacent channel rejection ratios for various modulation forms

Oooh... N Jay , I love it when you talk nerdy.

You and kv2vxa are something else.

I like how this thread was answered in post # 2 but yet . . .

 

[N_Jay]

I like how this thread was answered in post # 2 but yet . . .

And Grog's question in post 4 was answered in post 5. (My first post in the thread)

And WA4MJF's incorrect statement in post 8 was clarified in post 9.

And Warren's complete crap in post 10, was handles in post 11.

Yet, you seemed to feel there was a need for post 12? :roll:

 

[WA4MJF]

What was incorrect about mine? I think I recall when the FCC made the
change from wideband 36F3 to narrowband 16F3 is when ham VHF/UHF
FM took off because of the glut of wideband FM transcievers in the
surplus market. My first was a T43GCV on two meters
followed by a Progline on six meters. Of course, this was back in the
late 1960s, so I could be misremembering. Some users made their transmitters
narrowband and used the wideband receivers and turned the volume up.

 

[N_Jay]

What was incorrect about mine?

It was always Narrowband FM by the technical definition. It was further narrowbanded with each change. Part 90 land mobile has never "wideband".

It went from 36F3 narrowband FM to 16F3 narrowband FM, and now to 11F3 narrowband FM.

 

[WA4MJF]

Well, it all can't all be narrowband. Didn't the FCC refer to the 36F3 as wideband
when they were phasing it out and referred to 16F3 as narrowband. they
announced a date when all wide band transmissions would cease, but in the
interim both wide band and narrow band could be used. I think
I've heard 11F3 reffered to as sliver band, but not by the FCC, but
I cannot recall from whom.

 

[OceanaRadio]

It was always Narrowband FM by the technical definition. It was further narrowbanded with each change. Part 90 land mobile has never "wideband".

It went from 36F3 narrowband FM to 16F3 narrowband FM, and now to 11F3 narrowband FM.

I haven't been involved with the FCC side, but NTIA described 16F3 as "Wideband" when it became the standard, and it used that title even though it was indeed narrower than the previous standard. Likewise 11F3 has been dubbed "Narrowband" even though there were already applications for half of that bandwidth in special applications (but they were not a requirement). I'm reasonably sure that's why NJay mentioned the common-use descriptions, as they are indeed the terms used throughout the field. It only becomes relevant during a transitional period when both types of equipment are authorized. Right now there is no wideband anymore but when a new "narrower" standard becomes the requirement we will go through this all over again ;-)

Jack

 

[WA4MJF]

Jack, I think JTRS is not ready for prime time yet, but
getting there and, I recall that SINGARS
(it was coming in as I was retiring) is 36F3,
so what does NTIA call that?
We always called it WBFM in the Army.

 

[zz0468]

The occupied bandwidth of a standard FM communications channel is 10Khz (deviation +/- 5KHz) and NFM is 5KHz (deviation +/- 2.5KHz).

You forgot Carsons Rule...

Bandwidth= 2 (Δf + f m). Δf=Deviation, f m= Highest modulating frequency

A 3 KHz bw voice channel at 5 KHz deviation would have a 16 KHz occupied bw. Your 2.5 KHz deviation channel would have an occupied bw of 11 KHz.

 

[N_Jay]

Well, it all can't all be narrowband. Didn't the FCC refer to the 36F3 as wideband
when they were phasing it out and referred to 16F3 as narrowband. they
announced a date when all wide band transmissions would cease, but in the
interim both wide band and narrow band could be used. I think
I've heard 11F3 reffered to as sliver band, but not by the FCC, but
I cannot recall from whom.

"Widerband" and "Narrowband" have very little meaning unless you are saying wider then or narrower than something else.

Whereas; "Wideband FM" and "Narrowband FM" have very specific technical definitions.

Think "Hotter" and "Colder", vs. "Above freezing" and "below freezing"! Get it??