Basic Bandwidth Schooling

[prcguy]

The statement could have different meanings depending on how you read into it. If the OP meant to say the radios will work better on close channel spacing in the narrow band mode, then yes. If he meant the radios will work better in all respects in narrow mode, then no.

What did he really mean?
prcguy

Baloney...

 

[clbsquared]

There are no "narrow" or "wide band" frequencies. If you choose to transmit and receive on a specific frequency, let's say 151.1200, then you will simply enter 151.1200. That frequency will not change. However, when you transmit or receive on that frequency, the transmission that is sent out can be received on another radio that may be programmed with a frequency within 12.5 lower or higher than 151.1200. Wide band will give you 25 higher or lower than 151.1200 You will program your radio to either narrow or wide band. It makes no difference. The frequency will not change.

 

[clbsquared]

Think of it like a shotgun with two different types of barrels. The first being a modified choke. The pattern of the shot coming out of the end of the barrel will be wide. Now, if you replace that barrel with one that has a full choke, the pattern of the shot coming out of the barrel will be narrow and much closer together. Same shotgun shell, but different patterns.

 

[kayn1n32008]

There are no "narrow" or "wide band" frequencies. If you choose to transmit and receive on a specific frequency, let's say 151.1200, then you will simply enter 151.1200. That frequency will not change. However, when you transmit or receive on that frequency, the transmission that is sent out can be received on another radio that may be programmed with a frequency within 12.5 lower or higher than 151.1200. Wide band will give you 25 higher or lower than 151.1200 You will program your radio to either narrow or wide band. It makes no difference. The frequency will not change.

A narrow band transmission will deviate +/-2.5KHz from centre frequency, a wide band transmission will deviate +/-5KHz from centre frequency.


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[clbsquared]

A narrow band transmission will deviate +/-2.5KHz from centre frequency, a wide band transmission will deviate +/-5KHz from centre frequency.


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That's a much more simple explanation than mine.

Thanks

 

[kixntuff]

3Operations using equipment designed to operate with a 25 kHz channel bandwidth will be authorized a 20 kHz bandwidth. Operations using equipment designed to operate with a 12.5 kHz channel bandwidth will be authorized a 11.25 kHz bandwidth. Operations using equipment designed to operate with a 6.25 kHz channel bandwidth will be authorized a 6 kHz bandwidth. All stations must operate on channels with a bandwidth of 12.5 kHz or less beginning January 1, 2013, unless the operations meet the efficiency standard of §90.203(j)(3).

I thought 5KHz and above were considered wide band? That table shows 150-174 as 6KHz up to 20Khz I believe. Then you throw in the 2013 ruling, but I thought that would still be considered wideband? About the radio, I know it's not the correct radio to do what I'm doing here in the states and it will not be used to do any racing here in the states. Only in Ol Mexico where we are granted some freedoms from the Mexican government for a week. The radio even came modded from the shop I bought it off of with warranty seals all over it. I don't know if they knew it was modded because they didn't advertise it as such.

Thanks for all that comments fellas. This is really helping. Still trying to wrap my head and research some of the comments so I understand them better. I'm finding this very interesting.

 

[nd5y]

You're confusing deviation with bandwidth.
5 kHz deviation makes approximately 20 kHz bandwidth (wideband).
2.5 kHz deviation makes approximately 11.2 kHz bandwidth (narrowband).

Frequency modulating a carrier moves the carrier above and below its center frequency by the amount of deviation and also makes sidebands above and below the center frequency that are more than just the deviation alone.

 

[mmckenna]

About the radio, I know it's not the correct radio to do what I'm doing here in the states and it will not be used to do any racing here in the states. Only in Ol Mexico where we are granted some freedoms from the Mexican government for a week. The radio even came modded from the shop I bought it off of with warranty seals all over it. I don't know if they knew it was modded because they didn't advertise it as such.

Understood. I think I recall you saying that earlier.

The last few Yaseu radios I've purchased didn't have factory warranty seals on them, so I suspect the company you purchased from did that.

Thanks for all that comments fellas. This is really helping. Still trying to wrap my head and research some of the comments so I understand them better. I'm finding this very interesting.

This stuff can get confusing. The FCC rules, on their own, are not always easy to comprehend. You are getting some good advice, though.
If you are going to be using the Yaseu in Mexico, just match what they are telling you to do and don't get too hung up on it. Sounds like they are doing something special for the race. You won't be the only one with these radios down there. Also, you'll probably be going fast enough that they wouldn't be able to catch you, anyway.

 

[kixntuff]

You're confusing deviation with bandwidth.
5 kHz deviation makes approximately 20 kHz bandwidth (wideband).
2.5 kHz deviation makes approximately 11.2 kHz bandwidth (narrowband).

Frequency modulating a carrier moves the carrier above and below its center frequency by the amount of deviation and also makes sidebands above and below the center frequency that are more than just the deviation alone.

Could you provide some examples. using the band 150-174? I think I see what you're saying, but I want to make sure I understand it. I'm assuming there are a set amount of center frequencies in this band set a certain amount of KHz apart.

Thanks,

Kix

 

[ecps92]

Yes in the US as defined by the FCC, however you will need to talk to the Mexican Authorities as to their band plan, which is not the same as the US


FCC: Wireless Services: Industrial/Business: Data: Band Plan

https://transition.fcc.gov/oet/spectrum/table/fcctable.pdf

Here is the Business Band channel Plan
http://cfr.regstoday.com/47cfr90.aspx#47_CFR_90p35

Could you provide some examples. using the band 150-174? I think I see what you're saying, but I want to make sure I understand it. I'm assuming there are a set amount of center frequencies in this band set a certain amount of KHz apart.

Thanks,

Kix

 

[kixntuff]

Understood. I think I recall you saying that earlier.

The last few Yaseu radios I've purchased didn't have factory warranty seals on them, so I suspect the company you purchased from did that.



This stuff can get confusing. The FCC rules, on their own, are not always easy to comprehend. You are getting some good advice, though.
If you are going to be using the Yaseu in Mexico, just match what they are telling you to do and don't get too hung up on it. Sounds like they are doing something special for the race. You won't be the only one with these radios down there. Also, you'll probably be going fast enough that they wouldn't be able to catch you, anyway.

You hit that nail on the head. The race is 33 to 36 hours long and you'll be in some of the most remote desert imaginable. No mans land brotha. The big race radio companies that are involved kind of frown on the modded hams, 1 because they lost a sale and, 2 they claim which I've read as being correct, they don't transmit properly to the part 90 compliant radios because of filtering issues and such. Here's a pretty good read the main facilitator A.K.A. Weatherman put out. He works for PCI race radios. It's to try and minimize hundreds of racers from going hog wild with coms during the race. I'm at least trying to learn this stuff so I kind of half *** know what I'm doing and don't end up will the call name Richard Crainium over the airwaves. ;-) I've learned a lot from you guys in the past few weeks for sure. http://www.mattsnook.com/baja500/score2009files/WeathermanSpeaks.pdf

 

[kixntuff]

Yes in the US as defined by the FCC, however you will need to talk to the Mexican Authorities as to their band plan, which is not the same as the US


FCC: Wireless Services: Industrial/Business: Data: Band Plan

https://transition.fcc.gov/oet/spectrum/table/fcctable.pdf

Thanks for the links. For example then, 1st link says channel spacing is "Generally" whatever that means 7.5KHz apart. So when speaking to center frequencies would that be, 150.000, 150.0075, 150.015, 150.0225, etc etc moving all the way out to 174.000? Now, what does the bandwidth of 6KHz, 11.25KHz and 20KHz for those center frequencies look like?

 

[nd5y]

Could you provide some examples. using the band 150-174? I think I see what you're saying, but I want to make sure I understand it. I'm assuming there are a set amount of center frequencies in this band set a certain amount of KHz apart.

It's not that easy.
The FCC Industrial/Business Radio Pool frequency table lists all frequencies available for licensing to businesses and non public safety organizations.
Most of the frequencies in the 150-162 band are spaced 7.5 kHz apart and limited to 11.2 kHz bandwidth (2.5 kHz deviation) but there are some exceptions.

This has nothing to do with the 5, 10, 15, 20 kHz, etc., VFO tuning steps on a ham radio.

The general oversimplified rule of thumb for calulcating the occupied bandwith of an FM signal is
BW = F + D x 2

where
BW = bandwidth
F = highest modulating audio frequency
D = deviation
BW, F and D all must be in the same units (Hz or kHz)

 

[ecps92]

NO - see Toms Reply.

Plus (Again, US is NOT MX) 162.xxxx - 174.xxxx is mostly US Federal Government, you can not use those Frequencies in the US of A

Thanks for the links. For example then, 1st link says channel spacing is "Generally" whatever that means 7.5KHz apart. So when speaking to center frequencies would that be, 150.000, 150.0075, 150.015, 150.0225, etc etc moving all the way out to 174.000? Now, what does the bandwidth of 6KHz, 11.25KHz and 20KHz for those center frequencies look like?

 

[cmdrwill]

NO - see Toms Reply.

Plus (Again, US is NOT MX) 162.xxxx - 174.xxxx is mostly US Federal Government, you can not use those Frequencies in the US of A

No one in their right frame of mind would use the 162 -174 frequencies, even in Mexico......

 

[krokus]

This page gives some visuals, to help understand the concept.

http://www.raveon.com/data_radio_info/dual-bandwidth-capable-wide-and-narrow-band-explained-34/

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[kixntuff]

Thanks for the link. I like the way it spoke to wide band communicating with narrow band and vise versa. Sounds like everyone should be Tx'ing and Rx'ing on narrow band if I'm not mistaking for 150MHz to 155Mhx. Meaning I need to program my radio with all appropriate channels as narrow band so It will receive them as narrow band to narrow band correct?

Can we talk channel stepping now? Am I correct in saying that all licensed business race team frequencies should be stepped off of 150Mhz by 7.5Khz and therefor I should have my race team stepped off of that as well? For example, 150.0075, next would be 150.015, next 150.0225 etc etc? I want to get this right because I'm not supposed to have my team on a channel that's in-between frequencies.

Thanks,

Kix

 

[NDRADIONUT]

Arent you assigned a freq or freqs by the racing people ??

 

[ecps92]

ha ha ha ha, you mean FM users on NWS channels, or a stray from CN or MX who are here (Illegally or even Legally) and are 5, 10, 15 khz off a standard US Gov't Pair ?

Naw, never would happen in a million years
:roll:

No one in their right frame of mind would use the 162 -174 frequencies, even in Mexico......

 

[AK9R]

The general oversimplified rule of thumb for calulcating the occupied bandwith of an FM signal is
BW = F + D x 2

where
BW = bandwidth
F = highest modulating audio frequency
D = deviation
BW, F and D all must be in the same units (Hz or kHz)

I wondered when someone would get around to Carson's Rule.

F, in the case of FM radios use in two-way communications, is usually accepted to be 3 kHz since that's as much high frequency audio you need for effective comms.

So, for a +/- 5 kHz deviation, BW = 2 x (3.0 kHz + 5.0 kHz) = 16 kHz. The FCC emission designator for this type of transmission is usually 16K0F3E where "16K0" is the bandwidth and "F3E" means FM modulated analog voice.

And, for a +/- 2.5 kHz deviation, BW = 2 x (3.0 kHz + 2.5 kHz) = 11 kHz. The resulting emission designator is 11K0F3E.