Petitions for Reconsideration of Part 95 Personal Radio Services Rules Report and Order

[Mike_G_D]

I think the primary advantage of FM will be in utilizing radios equipped with CTCSS. That way you can squelch out co channel interference making CB more palatable for home use or a small business. The narrow band deviation does not offer much performance improvement over AM nor any appreciable FM capture effect. - Major EH Armstrong would not be impressed with +/- 2.0 KC.

Oh absolutely! I agree completely! We're really stretching the limits of the ability of FM to "shine" against AM with such a teensy bandwidth! I think the +/- 2.5 kHz deviation was stretching things as it is; +/- 2.0 kHz is pretty tight and you no longer get the AM noise suppression advantage you had with wider deviated FM nor, as you say, as good at capture effect. Maybe with some fancy modern I/Q demodulation and post-IF DSP processing things can be improved, buuuuut... (yes, before anyone asks - I/Q quadrature demodulators can be made to handle dang near any form of modulation, analog or digital which is why they are so bloody usefull!).

-Mike

 

[RFI-EMI-GUY]

Oh absolutely! I agree completely! We're really stretching the limits of the ability of FM to "shine" against AM with such a teensy bandwidth! I think the +/- 2.5 kHz deviation was stretching things as it is; +/- 2.0 kHz is pretty tight and you no longer get the AM noise suppression advantage you had with wider deviated FM nor, as you say, as good at capture effect. Maybe with some fancy modern I/Q demodulation and post-IF DSP processing things can be improved, buuuuut... (yes, before anyone asks - I/Q quadrature demodulators can be made to handle dang near any form of modulation, analog or digital which is why they are so bloody usefull!).

-Mike

As long as the designer has the "IQ" to put a front end RF filter before all of the "magic".

 

[Mike_G_D]

I think we went to great effort here on RR to dispel that proposal.

GMRS is just fine as it is.

I would like to see FM-FHSS in 27 MHz CB. I think it can be done rather cheaply with available technology.

Heh, well, I'll kind of agree with mmckenna here and I know you are in the majority and that makes me (and mmckenna) in the minority (a radio "heretic") but, I like the idea of GMRS going to very narrow NXDN, myself. I think the technology could be made very cheap, comparable to analog FM, these days with mass production. DMR allowing single frequency TDMA based repeaters sounds cool too but my knowledge of the full efficacy of that is not so good.

Anyway, as to FHSS on 27MHz - I do recall you or someone bringing that up in the past. Done right, it shouldn't interfere too badly with non-FHSS narrow band users but if widely used in a confined area, maybe. Still, opens up a LOT of potential "channels" without the need to expand the band. Interesting to ponder!

-Mike

 

[RFI-EMI-GUY]

Heh, well, I'll kind of agree with mmckenna here and I know you are in the majority and that makes me (and mmckenna) in the minority (a radio "heretic") but, I like the idea of GMRS going to very narrow NXDN, myself. I think the technology could be made very cheap, comparable to analog FM, these days with mass production. DMR allowing single frequency TDMA based repeaters sounds cool too but my knowledge of the full efficacy of that is not so good.

Anyway, as to FHSS on 27MHz - I do recall you or someone bringing that up in the past. Done right, it shouldn't interfere too badly with non-FHSS narrow band users but if widely used in a confined area, maybe. Still, opens up a LOT of potential "channels" without the need to expand the band. Interesting to ponder!

-Mike

Well; I am a bit of a Luddite when it comes to technology. I think there is a sweet spot in technology where a cave man can do it and get space man results. FM GMRS is one example. Sure you could switch it the NXDN or DMR (with great advantages) but then Motorola or Kenwood would have made the "D-GMRS" product proprietary and neither a cave man or spaceman can do it without paying for push to talk.

 

[Mike_G_D]

As long as the designer has the "IQ" to put a front end RF filter before all of the "magic".

That kinda goes without saying!

Yes, I do recall in the early days of digital cellular development I was involved with - DSP gurus pretty much ruled and, to their credit, were a pretty amazing folk! But I remember how some of them would say they could handle pretty much any form of "bad channel" and then later on down the road during integration testing (when us old RF weenies would start throwing in strong adjacent and alternate interferers and 3rd order intermod problems into the mix) would almost whine at us for throwing THAT kind of interference at them - that's just not FAIR!

-Mike

 

[Mike_G_D]

Well; I am a bit of a Luddite when it comes to technology. I think there is a sweet spot in technology where a cave man can do it and get space man results. FM GMRS is one example. Sure you could switch it the NXDN or DMR (with great advantages) but then Motorola or Kenwood would have made the "D-GMRS" product proprietary and neither a cave man or spaceman can do it without paying for push to talk.

I know and get what you're saying - a part of me agrees with that, too. I just kinda see both sides and feel, for the usage target that GMRS shoots for, a more sophisticated technology could reap huge benefits. Amateur radio already is a nice haven for both the "keep it simple and easily maintainable in harsh conditions and/or lack of fancy tools and test equipment" crowd as well as the "how do we push that Direct Sequence Spread Spectrum envelope a bit further" crowd.

But, I think you win anyway and don't want to make a huge deal about it here. Getting late at my end, food, mind numbing sheeple entertainment, and bed await.

All good discussion, though, have enjoyed it!

-Mike

 

[mmckenna]

But it will be nice to have as a consumer license-by-rule "low band" communication option! Especially if CTCSS is made workable and available at that deviation. Mmckenna would know best here, but it seems to me it might make a good option for off-roader use. Don't know, time will tell. I don't think it will "hurt" anything in the end - just nice to have as a "quieter option" for group communications.

I looked on the President CB European website, and they appear to have a few FM capable CB's that have CTCSS capability. So I guess they've made it work. Will be interesting to see how well it performs with the heterodyning AM signals and narrower bandwidth. Hopefully good filtering can allow it to work well. Using a non-standard CTCSS tone would be a handy solution for those that don't want to deal with all the other users.

I think the manufacturers and vendors that sell these new FM capable radios in the US will inflate the prices for a while to make the most money from those that want to play. Eventually the prices will stabilize, but I think FM will still be considered a 'premium' option, just like SSB is.

And like we saw with Digital Televisions, we'll probably see equally high priced "FM capable CB antennas". Should be pretty funny, actually. I'm sure there are those that will pay high prices for a "NEW FM capable CB antenna".

Here's the other issue I see:
I'm going to try to be really careful not to offend anyone here, but the average CB user is going to have a hard time with this. The average CB user won't know the difference between AM, SSB, FM, XM or RCA. There will be frustration. Trying to coordinate not only channel, but modulation and maybe CTCSS is going to be a challenge for some. Looking at the average consumer, FRS radios and "Privacy codes" have been difficult enough to understand, I think we'll have a lot of posts on this site from people asking for help.

But, for those that figure it out, I think it's going to be useful. Better audio, CTCSS/DCS squelch, etc. I can imagine a decent quality FM capable CB radio (that hasn't been jacked with by some golden screwdriver) with a good antenna, being a great resource for the off road community, as well as other hobbyists that are willing to put up a good antenna. Will be interesting to see if it catches on. There are a number of good options available to the consumer, CB, FRS, GMRS and MURS, so the battle of the bands will continue.

I wonder how big the market is for new CB radios, and if those that are in the market will be willing to pay for option of FM. Either way, I doubt we'll see basic AM only CB's go away.

No matter what, I think it's a good addition to the many radio services available. I hope that the manufacturers come out with some good radios with good features. Like Mike said, a consumer license by rule FM low band option.

 

[mmckenna]

Well; I am a bit of a Luddite when it comes to technology. I think there is a sweet spot in technology where a cave man can do it and get space man results. FM GMRS is one example. Sure you could switch it the NXDN or DMR (with great advantages) but then Motorola or Kenwood would have made the "D-GMRS" product proprietary and neither a cave man or spaceman can do it without paying for push to talk.

I think you are right on. It would be difficult to make any major changes to existing radio services now. GMRS is a great resource at it is, and I think it's under utilized and under appreciated.

But it's hard to look at that much spectrum in a prime slice of RF real estate and not see what could be done if the slate could be wiped clean and a fresh start given.

As for proprietary modes, The TDMA vs. FDMA battle is both good and bad. Both have their pro's and con's. I've played with both DMR and NXDN and found that they both can work well. But it's also created a division thats going to give us issues in the future. "True" 6.25KHz channels versus the "6.25 equivalent" thing is going to make any future refarming of our LMR bands difficult. But maybe we'll never need to go through that again. I would have personally preferred that the FCC had mandated true 6.25KHz channels. I've been fighting hard to find usable VHF pairs for some work stuff, and the mess that is the VHF band has stymied me at every step. Non-standard repeater splits, non-standard channel spacing, and all those agencies that migrated to 700MHz trunked that refuse to give up their VHF pairs.
But I'm off topic, and getting cranky thinking about that….

 

[RFI-EMI-GUY]

I think you are right on. It would be difficult to make any major changes to existing radio services now. GMRS is a great resource at it is, and I think it's under utilized and under appreciated.

But it's hard to look at that much spectrum in a prime slice of RF real estate and not see what could be done if the slate could be wiped clean and a fresh start given.

As for proprietary modes, The TDMA vs. FDMA battle is both good and bad. Both have their pro's and con's. I've played with both DMR and NXDN and found that they both can work well. But it's also created a division thats going to give us issues in the future. "True" 6.25KHz channels versus the "6.25 equivalent" thing is going to make any future refarming of our LMR bands difficult. But maybe we'll never need to go through that again. I would have personally preferred that the FCC had mandated true 6.25KHz channels. I've been fighting hard to find usable VHF pairs for some work stuff, and the mess that is the VHF band has stymied me at every step. Non-standard repeater splits, non-standard channel spacing, and all those agencies that migrated to 700MHz trunked that refuse to give up their VHF pairs.
But I'm off topic, and getting cranky thinking about that….

The FCC, and Industry really missed a golden opportunity to fix the problems in the VHF band at same time as with the narrow banding mandate. Duplex pairs could have been carved out and high power FB and low power MO's segregated. Very stupid and short sighted to ignore those challenges.

 

[mmckenna]

Very stupid and short sighted to ignore those challenges.

And costing taxpayers a LOT of money because I now have to build a system using 800MHz when I could have used VHF with less radio sites.

 

[Golay]

.... Not much going on the 10 meter and since they made the test stupid simple to get other bands, maybe push the tech class to upgrade. Just my thoughts on this subject.

How often you get on the air? There's quite a few of us here in Metro Detroit that ragchew thru the day on 28.330. Or have the radio parked there while putzing with other stuff. The band opens quite a bit, and we'll be talking around the world.

 

[Golay]

Just a blanket response to a few comments.
I think FM CB is going to be a good option for "wilderness" communications. A nice high base antenna monitoring a channel with the encode and decode enabled. Mobiles on snowmobiles and ATV's with a nice gain antenna or full length whip.
Handhelds with some of those "tape measure" antennas like they sell for the dual band CCR's now. Keep the antenna banded up. Make it full length when you need to get hold of someone.
Just my thoughts.

 

[Duckford]

How often you get on the air? There's quite a few of us here in Metro Detroit that ragchew thru the day on 28.330. Or have the radio parked there while putzing with other stuff. The band opens quite a bit, and we'll be talking around the world.

I've been monitoring CB and 10 meters a lot over the last year, almost daily, and often just letting the rig sit and monitor most of the night when I'm here. I'll tell you, for the last year at least, CB and 10 meter have been just about dead. Even when it does open up, it is unstable and difficult to make long contacts, and the band almost always shuts down hard in a few hours or less.

Those wanting to do some skywave are still waiting. And it may be a while.

 

[n7lrg]

I think there should be a gentle mans' agreement for band plan....Channels 1-10 for FM 11-30 for AM, 31-40 for SSB or something like that.

 

[mmckenna]

I think there should be a gentle mans' agreement for band plan....Channels 1-10 for FM 11-30 for AM, 31-40 for SSB or something like that.

CB? Gentleman? Surely you jest. Channel 6 is survival of the guy with the biggest amplifier. They are not going to move.

 

[vagrant]

The only thing that might fly is 1-19 for AM due to several obvious reasons, 20-30 for FM, and 31 and up for SSB. As mmckenna noted the two impossible words working together for this service, CB & Gentleman.

I think there should be a gentle mans' agreement for band plan....Channels 1-10 for FM 11-30 for AM, 31-40 for SSB or something like that.

 

[n7lrg]

Oh yeah...superbowl. I was thinking rationally. Vagrant you are right and your band plan makes more sense.

 

[KB4MSZ]

Do we dare try for spread spectrum?

 

[jhooten]

Do we dare try for spread spectrum?

Packet

 

[nd5y]

Packet

There has been packet on "freeband" for over 30 years.
Packet is 1970's technology that sucks for several reasons It's especially bad on HF. There are much better performing digital modes now.