Absolutely excellent presentation and description of this radio fundamental.... watched this just for fun and was really impressed with your easy to follow explanation. I'm sure many people will get a lot out of this!
This was very instructive and answered a lot of questions I had about the new BW's and the interference I've been getting annoyed with! Thanks Man Great Job!
Great video explaining the confusion with FRS and GMRS sharing. All your videos are great for us without radio knowledge or too old to learn tough complicated topics. Keep up the good work.
Thanks for the encouragement. Have lost a few viewers over technical disagreements but all-in-all it has been a great first month. Getting a dozen or so great questions a day. Viewers and subscribers have been very supportive! Thank you for your support! Respectfully - CommsPrepper
Great illustration of channel spacing and wide and narrow band considerations. Knowing that with technical advances and the FCCs ability to further allocated/assign channels to obtain additional revenue was also helpful.
Nothing is too technical. confusing yes but never negative. I find myself seeking out these videos once I've gotten to a certain level of understanding and then I say to myself.. oh wait I saw something on this before and I then Have To Have that information. Also you have a very good way of explaining that is very easy to understand.
Sir, thank you very much indeed, for your service to us, and for your very informative video. Yes, confusing but now it makes sense. Again, thank you very much, Sir.
Clear and concise, Thank you! I am still struggling to understand bandwidth. in a non "frequency modulation" broadcast for example AM, why would there by more than one frequency used by a single broadcast, if all we are doing is changing the power of the highs and lows of the oscillations for modulation shouldn't we only need one frequency per broadcast?
@ardorlan As technology has advanced and radio receivers have become mor selective less bandwidth is needed. the addition of digital modes has also reduced bandwidth requirements, The FCC is not stopping with narrowband 12.5KHz - 6.25KHz is already out there. However, each change must be phased in over time.
For international and cross country communications - 20 meters is the band you want. For State and regional communications you will want 80 and 40 meter capability. Hope this helps
You are not gonna lose subscribers because your video is dense, we enjoy it. Those that don't want to see jump to the next video. You could start your video with a label, like content: easy or content: hard. Good job!
@@Commsprepper , The sad thing, In the 90's I could hear NYFD and NYPD down here in South Central NJ. They narrowed the bands.. Well.. You know the rest.!! Thanks Bro 👍
You are very knowledgeable and a good teacher so will get a lot of support for your channel I’m sure. As for morse how about using it through computers, the old with the new as it were.
Ok...... so channel spacing means the frequency GAP between the CENTRE frequencies of 'adjacent' (immediate next door neighbour) channels. So between two centre frequencies of next-door-neighbour (adjacent) channels, the gap in frequency is 25 kHZ. The '16 kHz' is the absolute maximum bandwidth of a channel (ie. 8 kHz on each side of the centre frequency of a channel). The 10 kHz bandwidth is for safety, which means deliberately operating well under the absolute maximum allowed bandwidth - to be conservative.
Happy to do something on CW/Morse Code. Can you be more specific (history, benifits, new technologies)? Thanks for watching, liking, and subscribing. It's only been a month for my channel but it has been allot of fun!
I was hoping you would touch on, whats is better about wide band vs narrow band, and why doesn't the FCC just go to a ultra-narrow band, super-ultra-narrow band etc.. Why not just do 8hz spacing?
First of all I would like to thank you! Very nice video! I would also like to ask you what bandwidth you are using (16KHz or 10KHz) when you want to check if there are overlaps in GMRS at 8:04 and 10:34 !
GMRS does have overlap with some FRS channels. GMRS is wide-band and FRS is narrow-band. Although many GMRS makers ship them narrow-band. FCC cares that you stay in your assigned box.
FRS and GRMS and whatever rides the air would be effectively canceled out by frequency silencers. So in a nut shell postal service would make a come back. But if major structural things went down like normal in cases of bad weather or other wise frs and grms would be great in those situations where infrastructure was gone. Thanks for the information on how all that works on paper. Also could you put band stacking into equation on a single channel?
Response to question: 25 Yr. radio tech. See USMC Radio Handbook MCRP 3-40.3B FM - The amplitude of the modulating signal determines how far away from the center frequency the carrier will move. This movement of the carrier is called deviation; how far the carrier moves is called the amount of deviation. During reception of the FM signal, the amount of deviation determines the loudness or volume of the signal.
Thanks for the video. It was explained very well. I just want to understand here is it possible to reduce the channel spacing to lower than 12.5Khz? I mean why its not possible to take the advantage and reduce the spacing to for instance 1Khz so we can transmit extra frequency channels. Another important question; how many voice channel does Tetra accommodate/transmit?
I have struggled for a long time to understand the topic of channel spacing. This video drives it home in a very clear and concise way. Thank you for a very well put presentation and concise tutorial. I get it now. One question, is it possible to translate the channel spacing to Mb/s? Or does the actual bit rate depend on other factors?
Channel bleeding should not occure if only 2.5KHz bandwidth channels are used in spectrum using 2.5KHz channel spacing. Narrowband bandwidth and channel spacing/stepping are not a negative. What preppers should know is that differences exists and how it applies when programming you equipment. Hope this helps.
Thanks for the video, Im just getting started into radio and have a question regarding bandwidth for MURS, some channels are wide vs some are narrow bandwidths. does choosing wide vs narrow make a difference in rang, clarity, and is one better than the other for buildings vs outdoor use?
What do you mean when you say (@7:50) that the gmrs channel is using 25KHz of bandwidth, when you already said that 25KHz is the channel spacing. The bandwidth is 16KHz at the maximum. Am i correct?
Good info as usual brother. How about doing someting on ''cw'' (morse code for those that don't know) i am trying to use this mode, it's hard work but fun at the same time. Thanks again and keep them vids coming!
I have question between 1hz and 2 hz infinite number of hz ? Like 1.0001 1.0002 and goes on forever and never reach 2hz ? Because i been wondering like what does wide bandwidth and narrow means if there is many frequencies between 1 and 2 thats means infinite bandwidth or im wrong ?
Bandwidth changes the width of the transmit signal, quality radios will also adjust the receiver circuits to be more sensitive to narrower incoming signals.
25 K channels heard by 2.5K channels, will often clip as the channel bandwidth is excessive for 2.5K channel spacing. I run narrow band on GMRS, not wide band. Set deviation for narrow band, so it hits the +/- 2.5 channel bandwidth, but you can turn mic gain up just slightly, and maintain full narrow band use without over deviating or co-channel 'splatter'.
very useful video and really well explained, will be good if you can enable translations for the video, so we can add translations for more languages, in subtitles.
I don't recommend Beufeng radios for anything but holding the bottom of a trash bag down. Additionally, they are only FCC approved for the Amateur radio service - not MURS/FRS/GMRS.
What if I use DC with pulsations then would I be considered belong to any of those frequency or band with because it it totally out of classification so am I considered for paying fee?
@@Commsprepper Thanks for reply! But Terms not clear till now. The term Channel width is used for channelised equipments and term Occupied BW is used for Non-Channelised equipments. Are both same or different?
You are right, I did not address the coming of 6.25kHz. Let me know when you post a video on 6.25 and I will mention it on the channel. Thanks for watching and commenting.
Could you please get everything which you are presenting here correct? I applaud and praise your presentation and effort, but just get it all correct...
Commsprepper Channels carriers paths, etc are confusing and not well defined anywhere, let alone by you. Assigned carrier = licensed marker center frequency authorized by the FCC for some particulate person or entity to used for communications: transport of information from one location to another without the use of wires or fiber technology. FCC Licenses users to place their communication on a particular frequency (carrier), of a particular bandwidth, at a particular power level using a particular modulation technology. These frequencies of which you are speaking are NOT sold by the FCC, the spectrum is owned by the citizens of the USA, the FCC rides "trail boss" over citizens use of the spectrum, to keep order and consistency, and to prevent one from incumbering others - known loosely as interference. Then there is segments of the spectrum which is "sold" of sorts. It is still owned by the citizens, but a short-cut to authorization is this competitive bidding by a dollar amount, a means to garner revenue for the US Treasury from the use of the public spectrum, also know as a tax.. but only to those persons who pay attention... These are the common carrier or 'cellular' and other commercial 'wireless' companies who obtain authorization to provide radio services to the general public, who only need to purchase usage from the providing company, or "common carrier", which is a company and not a Radio Frequency carrier... Yes, confusing at time. So each time you pay your cellular bill, you are sending revenue to that provider company who has "purchased" your spectrum (citizen owned) for its use, and the purchase price goes to the US Treasury!! Private Radio Services covers the category of radio you have been talking about: Business, police, fire, utility, municipal, railroad, land transportation, etc. for Private Radio (pt 90) Citizens Radio (pt 95) Amateur Radio (pt 97), Aviation Radio (pt 87), Maritime Radio pt 80), Then it goes into the others which are summarized as "non-private" which includes broadcast and cellular among others. Go to for a link to the actual Rules Parts... Now channel steps, bandwidth, narrowband, wideband, broadband... Another quagmire of lost and insufficient definitions. Simply; there are no hard definition for any of these 'bandwidths', that leaves them as merely relative indicators and not absolute entities.. Sad but true. Let us state that the channel steps are not bandwidth, but rather are the steps or distance (spacing) between "authorized carriers" which are the reference marks for the location of the radio energy used to carry information from one location to another by a particular "signal". The bandwidth is the amount of spectrum consumed by that energy in order to transport the information. Known as "occupied bandwidth" the location where the particular signal energy is situatied in the spectrum. Now, the specified bandwidth by the FCC is that which is felt will prevent undue disruption to other users of the spectrum, specifically the adjacent spectrum to that authorized carrier. Now, I can demonstrate how they (FCC etc) have disabled that concept, however let us just stay with the basics for now.. The modulation type (technology) and information flow rate are the controlling factors for occupied bandwidth. The FCC wants stuff within certain limits, hence us good citizens must constrain our communications in order to 'comply " with those limits. The bandwidths and channel spacings you were describing were set up to promote that "order" and prevent chaos.. Narrowband channels (carriers) were created to provide more pathways for more persons to use within the overall constraints of spectrum. Remember spectrum is not a single dimensioned entity, it is multi-dimensional: Frequency (where in the spectrum), geographic location (GA, NY, MT, CA, East of Mt Washington, West of Mt Washington...), power level of the transmitted signal (strong, weak, short range..), calendar time of the transmission (only at 2:00 PM, Only on Tuesdays...), and timing relation of the transmission (only in Tuesdays after 3:00 PM, not during the 2:00 PM transmission..).. Known as shared spectrum.. So I am tiring out here and will complete this stage by saying that your effort is well noted and appreciated. I fully support your intentions, however I appeal to you to get the facts correct. I urge you to NOT rely on Wikipedia, as it is only a populace propaganda tool and not a true reference. Use it superficially to obtain an idea then refine that with facts. Look at the FCC Rules & Regulations, they are free from that web site I provided to you. First, read and understand the definitions sections of each of the radio parts and services. Then build your case and system.
Sorry, don't know what your background is, but you don't understand the physics and math involved here. Repeating what you already said is not convincing those with knowledge. You also assume a reciprocity between the two bands, when there is none: GRMS will be able to deal with the narrower FRS just fine, because there is plenty of bandwidth in the circuitry. You just lost a new subscriber. Best to you.
This is an 8 year old video, but was exactly what I was looking for. Thank you.
Glad it helped!
Absolutely excellent presentation and description of this radio fundamental.... watched this just for fun and was really impressed with your easy to follow explanation. I'm sure many people will get a lot out of this!
Thank you.
I am learning more from your videos than any other source. Many thanks for the professionalism of the presentations.
Excellent information, especially for us "newbies". Great video. Thank you Sir, for your help to all of us.
Oscar
This vid has good timing. My department is switching to narrow band tomorrow and this helped me understand it better. Thanks.
Wow! Excellent video! This video will be a great resource work the prepping community for a very long time. Congratulations!
Your explanation was very clear on band width and channels spacing. It clear my mind of some confusions. Thank you sir.
This was very instructive and answered a lot of questions I had about the new BW's and the interference I've been getting annoyed with! Thanks Man Great Job!
Great video explaining the confusion with FRS and GMRS sharing. All your videos are great for us without radio knowledge or too old to learn tough complicated topics. Keep up the good work.
Finally got around to viewing this video. Wish I’d seen it sooner! Very well presented. Thanks.
Thanks for the comment and channel support.
Thanks for the encouragement. Have lost a few viewers over technical disagreements but all-in-all it has been a great first month. Getting a dozen or so great questions a day. Viewers and subscribers have been very supportive! Thank you for your support! Respectfully - CommsPrepper
Great illustration of channel spacing and wide and narrow band considerations. Knowing that with technical advances and the FCCs ability to further allocated/assign channels to obtain additional revenue was also helpful.
Thanks.
Then they will divide it again with 6.25 KHz spacing. 🤣
Hey many thanks for your video it was very well illustrated and made me understand something I've had trouble with. Good job !
+Daire Lyne Thank you for the feedback and taking the time to watch and comment. Respectfully - Hank
Thank you very much Commsprepper, very well explained with graphics. Now I will check out all your other videos
Very very great video! I learned a lot. Thanks so much.
I'm happy it helped.
Really enjoying your channel and I am learning a lot. Keep up the great work.
Fantastic video. Helped me understand bandwidth in general. Thank you!
thanks
Nothing is too technical. confusing yes but never negative. I find myself seeking out these videos once I've gotten to a certain level of understanding and then I say to myself.. oh wait I saw something on this before and I then Have To Have that information. Also you have a very good way of explaining that is very easy to understand.
Sir, thank you very much indeed, for your service to us, and for your very informative video. Yes, confusing but now it makes sense.
Again, thank you very much, Sir.
Glad the video helped
Outstanding presentation. Subscribed.
Thank you
Very informative video.
Thank you Sir.
Oscar
Brilliant explanation and graphics, I was trying to find a simple explanation of this exact subject matter.
Glad it helped.
Clear and concise, Thank you!
I am still struggling to understand bandwidth. in a non "frequency modulation" broadcast for example AM, why would there by more than one frequency used by a single broadcast, if all we are doing is changing the power of the highs and lows of the oscillations for modulation shouldn't we only need one frequency per broadcast?
@ardorlan As technology has advanced and radio receivers have become mor selective less bandwidth is needed. the addition of digital modes has also reduced bandwidth requirements, The FCC is not stopping with narrowband 12.5KHz - 6.25KHz is already out there. However, each change must be phased in over time.
Thanks a lot. I appreciate your lecture so simple.
Glad it helped.
For international and cross country communications - 20 meters is the band you want.
For State and regional communications you will want 80 and 40 meter capability.
Hope this helps
Great training! Keep up the good work.
You are not gonna lose subscribers because your video is dense, we enjoy it. Those that don't want to see jump to the next video. You could start your video with a label, like content: easy or content: hard. Good job!
AWESOME 👍 vid. It's slowly starting to make sense! Now the whole concept of antenna type has become much more clear 👊
Glad it helped. Thanks for the channel support and comment.
@@Commsprepper , The sad thing, In the 90's I could hear NYFD and NYPD down here in South Central NJ. They narrowed the bands.. Well.. You know the rest.!! Thanks Bro 👍
You are very knowledgeable and a good teacher so will get a lot of support for your channel I’m sure.
As for morse how about using it through computers, the old with the new as it were.
will 2.5 narrow band stepping help and possibly reduce channel bleeding? And to do see having a radio with with 2.5 stepping a plus for peppers or not
Thank you. Let me know if there is a specific topic you would like covered.
Okay. Ordered NMO cable kit today. Will have a video in a few weeks. Thanks for subscribing and watching - commsprepper.
Ok...... so channel spacing means the frequency GAP between the CENTRE frequencies of 'adjacent' (immediate next door neighbour) channels. So between two centre frequencies of next-door-neighbour (adjacent) channels, the gap in frequency is 25 kHZ. The '16 kHz' is the absolute maximum bandwidth of a channel (ie. 8 kHz on each side of the centre frequency of a channel). The 10 kHz bandwidth is for safety, which means deliberately operating well under the absolute maximum allowed bandwidth - to be conservative.
Happy to do something on CW/Morse Code. Can you be more specific (history, benifits, new technologies)? Thanks for watching, liking, and subscribing. It's only been a month for my channel but it has been allot of fun!
I was hoping you would touch on, whats is better about wide band vs narrow band, and why doesn't the FCC just go to a ultra-narrow band, super-ultra-narrow band etc.. Why not just do 8hz spacing?
Good job. Cleared up some for me. Thank you.
Glad it helped
First of all I would like to thank you! Very nice video! I would also like to ask you what bandwidth you are using (16KHz or 10KHz) when you want to check if there are overlaps in GMRS at 8:04 and 10:34 !
GMRS does have overlap with some FRS channels. GMRS is wide-band and FRS is narrow-band. Although many GMRS makers ship them narrow-band. FCC cares that you stay in your assigned box.
Thank you for the feedback. Feel free to suggest topics you would live covered. Respectfully - CommsPrepper.
@egn83b I don't understand the question (band stacking into equation). Can you rephrase it?
FRS and GRMS and whatever rides the air would be effectively canceled out by frequency silencers. So in a nut shell postal service would make a come back. But if major structural things went down like normal in cases of bad weather or other wise frs and grms would be great in those situations where infrastructure was gone. Thanks for the information on how all that works on paper. Also could you put band stacking into equation on a single channel?
Response to question: 25 Yr. radio tech. See USMC Radio Handbook MCRP 3-40.3B FM - The amplitude of the modulating signal determines how far away from the center frequency the carrier will move. This movement of the carrier is called deviation; how far the carrier moves is called the amount of deviation. During reception of the FM signal, the amount of deviation determines the loudness or volume of the signal.
Thanks for the video. It was explained very well. I just want to understand here is it possible to reduce the channel spacing to lower than 12.5Khz? I mean why its not possible to take the advantage and reduce the spacing to for instance 1Khz so we can transmit extra frequency channels.
Another important question; how many voice channel does Tetra accommodate/transmit?
I have struggled for a long time to understand the topic of channel spacing. This video drives it home in a very clear and concise way. Thank you for a very well put presentation and concise tutorial. I get it now.
One question, is it possible to translate the channel spacing to Mb/s? Or does the actual bit rate depend on other factors?
Happy to help and thank you.
Great explanation
Thank you.
I suspect your department also went digital when they narrow-banded (P25 mode).
Do a video on base antenna quality and set up... or mobile radio installation for dummys... just a thought
Channel bleeding should not occure if only 2.5KHz bandwidth channels are used in spectrum using 2.5KHz channel spacing. Narrowband bandwidth and channel spacing/stepping are not a negative. What preppers should know is that differences exists and how it applies when programming you equipment. Hope this helps.
can I know more about "channel spacing"?
Thanks for the video, Im just getting started into radio and have a question regarding bandwidth for MURS, some channels are wide vs some are narrow bandwidths. does choosing wide vs narrow make a difference in rang, clarity, and is one better than the other for buildings vs outdoor use?
wide band has a bit more range but with newer digital modulation modes it's negligible .
What do you mean when you say (@7:50) that the gmrs channel is using 25KHz of bandwidth, when you already said that 25KHz is the channel spacing. The bandwidth is 16KHz at the maximum. Am i correct?
Thanks for pointing this out. I should have been more specific and mention the guard space on the channels.
And I forgot to thank you for this video😅. Good work.
thank you! good video.
Good info as usual brother.
How about doing someting on ''cw'' (morse code for those that don't know)
i am trying to use this mode, it's hard work but fun at the same time.
Thanks again and keep them vids coming!
Thank you!
I have question between 1hz and 2 hz infinite number of hz ? Like 1.0001 1.0002 and goes on forever and never reach 2hz ? Because i been wondering like what does wide bandwidth and narrow means if there is many frequencies between 1 and 2 thats means infinite bandwidth or im wrong ?
Excellent explanation, thank you.
Does changing your bandwidth only effect receiving or both?
Bandwidth changes the width of the transmit signal, quality radios will also adjust the receiver circuits to be more sensitive to narrower incoming signals.
25 K channels heard by 2.5K channels, will often clip as the channel bandwidth is excessive for 2.5K channel spacing.
I run narrow band on GMRS, not wide band.
Set deviation for narrow band, so it hits the +/- 2.5 channel bandwidth, but you can turn mic gain up just slightly, and maintain full narrow band use without over deviating or co-channel 'splatter'.
thanks for the comment.
very useful video and really well explained, will be good if you can enable translations for the video, so we can add translations for more languages, in subtitles.
which would you recommend to set on baufeng radios (murs) ?
I don't recommend Beufeng radios for anything but holding the bottom of a trash bag down. Additionally, they are only FCC approved for the Amateur radio service - not MURS/FRS/GMRS.
Good video sir
What if I use DC with pulsations then would I be considered belong to any of those frequency or band with because it it totally out of classification so am I considered for paying fee?
I don't understand your question. Are you talking about spark-gap transmitters?
Thanks, I now understand
Glad it helped. Thanks for the channel support.
thanks for the info!
Glad it helped.
thank you!
You're welcome!
THank you.
So if I go from 25khz to 12.5 khz does that give me more range on my cp200 uhf
25kHz will have a bit more range with respects to signal to noise but it's hard to measure (in my opinion).
Great stuff, thanks.
Can you pls clear the term 'channel width' and 'bandwidth'?
clear it how? Make a new video - no way.
@@Commsprepper Thanks for reply! But Terms not clear till now. The term Channel width is used for channelised equipments and term Occupied BW is used for Non-Channelised equipments.
Are both same or different?
really thanks, bro. by the way if u have time ,pls explain OCI (optical channel interlever) for DWDM . I'm really hoping . thanks. have a nice day
I have no idea what OCI is - sorry.
really thanks,
that's what i was looking for, thanks indeed,
could you give me a vedios about spectrum allotment,
thank you
Nice
You left out the 6.25 KHz super narrow band.
You are right, I did not address the coming of 6.25kHz. Let me know when you post a video on 6.25 and I will mention it on the channel. Thanks for watching and commenting.
lol I'm not posting a video on it. I do not like making videos
Could you please get everything which you are presenting here correct? I applaud and praise your presentation and effort, but just get it all correct...
You will need to be more specific. What is not correct?
Commsprepper
Channels carriers paths, etc are confusing and not well defined anywhere, let alone by you. Assigned carrier = licensed marker center frequency authorized by the FCC for some particulate person or entity to used for communications: transport of information from one location to another without the use of wires or fiber technology.
FCC Licenses users to place their communication on a particular frequency (carrier), of a particular bandwidth, at a particular power level using a particular modulation technology. These frequencies of which you are speaking are NOT sold by the FCC, the spectrum is owned by the citizens of the USA, the FCC rides "trail boss" over citizens use of the spectrum, to keep order and consistency, and to prevent one from incumbering others - known loosely as interference. Then there is segments of the spectrum which is "sold" of sorts. It is still owned by the citizens, but a short-cut to authorization is this competitive bidding by a dollar amount, a means to garner revenue for the US Treasury from the use of the public spectrum, also know as a tax.. but only to those persons who pay attention... These are the common carrier or 'cellular' and other commercial 'wireless' companies who obtain authorization to provide radio services to the general public, who only need to purchase usage from the providing company, or "common carrier", which is a company and not a Radio Frequency carrier... Yes, confusing at time. So each time you pay your cellular bill, you are sending revenue to that provider company who has "purchased" your spectrum (citizen owned) for its use, and the purchase price goes to the US Treasury!! Private Radio Services covers the category of radio you have been talking about: Business, police, fire, utility, municipal, railroad, land transportation, etc. for Private Radio (pt 90) Citizens Radio (pt 95) Amateur Radio (pt 97), Aviation Radio (pt 87), Maritime Radio pt 80), Then it goes into the others which are summarized as "non-private" which includes broadcast and cellular among others. Go to for a link to the actual Rules Parts...
Now channel steps, bandwidth, narrowband, wideband, broadband... Another quagmire of lost and insufficient definitions. Simply; there are no hard definition for any of these 'bandwidths', that leaves them as merely relative indicators and not absolute entities.. Sad but true. Let us state that the channel steps are not bandwidth, but rather are the steps or distance (spacing) between "authorized carriers" which are the reference marks for the location of the radio energy used to carry information from one location to another by a particular "signal". The bandwidth is the amount of spectrum consumed by that energy in order to transport the information. Known as "occupied bandwidth" the location where the particular signal energy is situatied in the spectrum. Now, the specified bandwidth by the FCC is that which is felt will prevent undue disruption to other users of the spectrum, specifically the adjacent spectrum to that authorized carrier. Now, I can demonstrate how they (FCC etc) have disabled that concept, however let us just stay with the basics for now.. The modulation type (technology) and information flow rate are the controlling factors for occupied bandwidth. The FCC wants stuff within certain limits, hence us good citizens must constrain our communications in order to 'comply " with those limits. The bandwidths and channel spacings you were describing were set up to promote that "order" and prevent chaos.. Narrowband channels (carriers) were created to provide more pathways for more persons to use within the overall constraints of spectrum. Remember spectrum is not a single dimensioned entity, it is multi-dimensional: Frequency (where in the spectrum), geographic location (GA, NY, MT, CA, East of Mt Washington, West of Mt Washington...), power level of the transmitted signal (strong, weak, short range..), calendar time of the transmission (only at 2:00 PM, Only on Tuesdays...), and timing relation of the transmission (only in Tuesdays after 3:00 PM, not during the 2:00 PM transmission..).. Known as shared spectrum.. So I am tiring out here and will complete this stage by saying that your effort is well noted and appreciated. I fully support your intentions, however I appeal to you to get the facts correct. I urge you to NOT rely on Wikipedia, as it is only a populace propaganda tool and not a true reference. Use it superficially to obtain an idea then refine that with facts. Look at the FCC Rules & Regulations, they are free from that web site I provided to you. First, read and understand the definitions sections of each of the radio parts and services. Then build your case and system.
Sorry, don't know what your background is, but you don't understand the physics and math involved here. Repeating what you already said is not convincing those with knowledge. You also assume a reciprocity between the two bands, when there is none: GRMS will be able to deal with the narrower FRS just fine, because there is plenty of bandwidth in the circuitry. You just lost a new subscriber. Best to you.
Great, simple explanation.
Thanks.
Good video VU3RFN