Guest Post: Citizens Band FM mode is long overdue

Many thanks to SWLing Post contributor, Peter Laws, who shares the following guest post:

Adding FM as an allowable mode on CB seems long overdue

by Peter Laws

The FCC’s recent action to add FM as an allowable mode on CB seems long overdue.  See the final rule as published in the Federal Register on September 28, 2021:

Looking through old CB and amateur radio magazines from the 1970s it appears that the FCC considered allowing FM around the time that the service expanded to 40 channels.  The FCC being the FCC took their usual “what’s the least we can do to make this issue go away?” path and just added 17 new channels starting at the beginning of 1977.  Other than that expansion, they didn’t really change anything.  There were incumbents on the spectrum re-allocated to CB, too, and licensees were given a 2-year grace period to vacate what was to become channels 24, 25, and 26 and up.

Personally, your humble reporter is happy that the Commission has finally allowed FM on CB.  This should be a big improvement for people who are actually trying to communicate.  The reduction of static alone will be welcome.  There are claims that AM has better range than FM at the same power levels.  I suspect that people who make that claim are confusing AM broadcast (on MF) to FM broadcast (on VHF) but the proof will be in the pudding once we start to see new FM CBs hit the market.

And what about that?  When will we see new radios?  It should happen pretty quickly, almost certainly by the end of the year “Christmas” rush assuming no supply chain delays.  If you are unfamiliar with CB outside of North America, you may be surprised to find that radios that will meet the new FCC rules already exist.  I don’t mean those quasi-legal “Export” radios that many are fond of, but main-stream consumer radios from vendors like Midland, Cobra (the petitioner that got FM approved), Uniden, and President.

If you are an amateur licensee, you may be familiar with CEPT, the Conférence européenne des administrations des postes et des télécommunications.  That’s an association of the various FCC equivalents (and USPS equivalents) in each of the European nations.  In the amateur world, CEPT has a simple reciprocal licensing regime that allows US amateurs to operate in CEPT countries and amateurs from CEPT countries to operate in the US without any extra paperwork.  CEPT also works to harmonize radio and other telecommunication rules regimes between the different nations to make it easier for vendors to build equipment acceptable to all and making the market bigger.

For the most part — there are exceptions — CEPT nations have all adopted the same CB radio band plan and rules.  Here’s the surprise: they are nearly identical to the FCC rules!  Same 40 channels, even with the weirdness between channels 22 and 25 and the skipped channels for radio control, the 4 W power output, etc.  The only big difference is that CEPT allows FM in addition to AM and SSB.

So a CEPT-spec radio will meet the new FCC rules today.  A vendor will simply need to make certain that their product’s firmware and other components really do match US requirements, get it tested by a contract certification facility (those facilities will also need to update their FCC CB test procedures for the addition of FM), and file the paperwork with the Commission.  This is far simpler than actually having to engineer the addition of FM to an existing AM-only product.

One jurisdiction that has their own rules, in addition to allowing CEPT rules, is the United Kingdom.  When CB was legalized in the UK in 1981, the government allowed FM (only) on 40 channels that start at 27.60125 MHz and go up every 10 kHz to 27.99125 MHz.  A decade or two after that, the UK also made operation of CEPT-spec CB radios legal with the result being the UK CBers have 80 legal channels available – 40 CEPT channels with all three modes and an additional 40 with FM only.

Don’t expect to see “multi-norm” radios in the US like those marketed in Europe.  Multi-norm units allow for switching between CEPT, UK, and other national channel/power/mode layouts, often with only a few simple button presses.  Historically, the FCC has been reluctant to allow radios that have user-adjustable operating parameters outside of the Amateur Radio Service so watch for firmware on US versions to be locked down.

Undoubtedly, some will claim that this is all being done so that Cobra (the petitioner in this case) can sell more radios.  What is the problem with this?  The new rules do not change anything with regard to the current rules.  If you have a legal AM or AM/SSB radio now, you will still have a legal AM or AM/SSB radio after October 28, 2021.  And after that, it will be legal to sell an FCC-approved radio that includes FM in addition to AM or AM and SSB.  That’s right – radios may include FM but must have AM.

Generally speaking, I am one that is not in favor of deregulation.  But if you look through old FCC regulations, either in Part 97 (Amateur) or Part 95 (CB, GMRS, et al), there really were a lot of silly regulations.  But only silly by the time they went away; at the time they were created they were, or were at least thought to be, vital.  Time showed that some of those rules really weren’t vital and many have been removed.  One of those rules was the 250-km limit on CB communications.  It’s likely that at the time the rule was promulgated it was intended to reinforce that Class D CB (as it was known then) was intended as a short-range communications system.  The ionosphere made sure that the “DX rule” was nearly impossible to enforce as even regular, law-abiding citizens could and did answer a “breaker” who ended up being 1000 miles away!  In Cobra’s initial 2017 petition to the FCC, they requested abolition of the distance limit and the Commission agreed but in that same Report and Order, they declined to add FM.  Cobra petitioned for reconsideration of that point (FM) and here we are.

While there are still allocations for other services between channel 40 and the start of the 10-m amateur band, and while there are still licensees there, it is hard to imagine that those licensees are actually using that spectrum.  Free-banders, yes, licensed stations, unlikely.  A quick tour of the Commission’s Universal Licensing System shows a number of licensees in the spectrum between channel 40 (27.405 MHz) and the start of the amateur allocation at 28.0 MHz.  Most, however, appear to be dealers, consultants, and manufacturers in the communications business that are required to have blanket licenses for any band that they intend to use.  As a result, there are many licenses that cover 25-50 MHz (and many other bands) inclusive for demonstration purposes.

So where is this story going?  Why not petition the FCC to allow UK-spec radios to be used in the US?  Literally, almost no one is using this spectrum aside from freebanders that may already be there.  The reason that the Congress reserved to itself the ability to regulate the radio spectrum, later delegated to the FCC, was to ensure that the spectrum was used in the most efficient manner possible and to prevent interference.  Since almost no one uses this patch of spectrum at 27 MHz, why not let it become an expanded “national park” for hobbyists?

If you are thinking, “well, if the FCC does that for 27 MHz, why not new bands in other, largely-abandoned spectrum?”  This reporter’s answer is “sure, why not?”  This is, after all, how amateurs got bands at 630 and 2200 meters – the spectrum was largely abandoned.  WL2XUP is an Part 5 experimental station that is transmitting various digital modes between 40.66 and 40.7 MHz.  This roughly aligns with 8-meter amateur allocations that are popping up in other jurisdictions.  Maybe this 8-meter experiment, too, will pave the way to a new allocation like the Part 5 operations did on the new MF and LF bands mentioned above.

It’s a brave new world in CB.

Peter Laws has been licensed as a ham since 1991 (after a false start c.1978), has listened to scanners since 1982, was on CB in the late 1970s, and started DXing on MW and SW in the mid-1970s.  He edits columns in both LWCA’s Lowdown and IRCA’s DX Monitor.  He lives in Norman, Oklahoma, with his wife, several small doggoes, and many radios and antennas.

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8 thoughts on “Guest Post: Citizens Band FM mode is long overdue

  1. John K5MO

    It’s interesting that this is authorized just as the MUF is heading up to 30Mhz. It’ll be fun to hear the return of the squeal of the hetrodynes alongside linear amped FM transmitters fighting for the “capture” rights. 🙂

  2. John K5MO

    I suggest that following in a similar vein, the FCC take up authorizing spark transmission between 14 and 30Mhz, and allowing AM stereo on the 30 M.

    After all, “no interference will be caused since the person hearing the signal can tune to another frequency”.

  3. Patrick

    FM on CB will not have a long term huge affect on sales. GRMS is far better because you can have 50 watts on the main GRMS channels plus you can have long range repeaters excatly like the HAM’s use on UHF 70 cm band. The bandwidth is far to narrow on CB FM to be of any use, and then add the noise makers, echo and over driven audio to the mess. If they would allow 100 SSB and 50 watts AM, this would be helpful to fighting QRM on 11 meters and drop the FM idea all together.

  4. Bas PE4BAS

    New Zealand 40 channels are in the 26MHz, UK 40 channels still allowed just below 28MHz. Many CB users do DX between 27,4-28 MHz as a hobby. There are more countries that have extra channels in the 26MHz. My believe is that they should free CB from 26-28MHz all mode worldwide. And even if they do I don’t think CB will be much more populair. In the Netherlands we got FM from the start in the early eigthies of last century. FM has advantages but also disadvantages just like AM. Cheap communication between mobile/mobile is done with cheap Baofeng transceivers these days, people just choose a clean frequency illigal or not (most don’t really know). Besides that, most people have a mobile phone, who cares about CB anyway?

  5. Rob W4Zng

    “assuming no supply chain delays.”
    Hm, so sometime early 2023 then?

    Supply chain issues aside, by allowing CB to function in RFI burdened environments, perhaps this change will allow the band come back as the inexpensive comms method of choice for people who need a little more range than FRS. It’s going to be interesting to see how this shakes out. In any case, it’s a good excuse for me to go out and buy more gear!

  6. mangosman

    I agree with Michael’s comments. If you try and fit an FM signal in a bandwidth of an SSB CB channel, the deviation is so low, there is no noise or range advantage.

    Living outside the USA, I note the other following technical disasters the FCC has inflicted on North America.

    Analog National Television Systems Committee standardised ‘Never Twice the Same Colour’ for TV. It was the only system which required a front panel control called Hue. PAL used the same technology but added a glass delay line to enable hue correction to be intrinsic. The USA said it would cost too much, but when you make products by the millions the costs come down.

    The NTSC standard required the use of 3.579545 MHz subcarrier to minimise a coloured wavy pattern caused by the sound. The end result is that it is not divisible down to 30 Hz which was the monochrome frame rate. This not only makes timecode for editing having to “drop frames”, it also caused the Compact Disc sample rate not to be divisible to 30 or 25 frame/s. Fortunately now digital audio is sampled at 48 kHz which is divisible.

    When digital TV started the USA repeated the NTSC debacle by creating the American Television Systems Committee which adopted a system which did not use the COFDM modulation which eliminates reflected signals. With the exception of Canada, Mexico, South Korea the rest of the world uses COFDM. Now finally ATSC3.0 uses COFDM.

    HD radio is the latest. There is no sign of all digital HD radio in the FM band. DAB+ and DRM have live broadcasting using much higher power because it is not trying to prevent interference with adjacent channel FM or AM signals. India for example is transmitting DRM at 1 million Watts.

  7. Michael Black

    The only time I remember serious discussion of FM for CB was in the early seventies, the EIA proposing a CB band instead of the 220MHz ham band. So add a band, make it FM, have way more channels and allocate for channels specific purposes.

    I do remember one plan for more CB channels at 27MHz, until some math was done and a realization that there’d be problems.

    AM stereo failed, one reason seems to be that the FCC didn’t pick one method, but allowed multiple formats, so nothing was successful. When the FCC decided the 2-3MHz marine band should go SSB in the seventies, it set a deadline well in advance. And it opened up a marine band at about 156MHz, FM, where small boat owners moved. Analog tv went away by a drastic change to DTV, while previously color and stereo had been tacked on to the existing standard.

    FM comes to CB over sixty years after it was launched. Its peak time is passed. For businesses needing communication, there’s GMRS, MURS, and even cellphones. FRS seems to get more attention than CB. I don’t see FM making much impact. They couldn’t ban AM, so this sits on top. If people actually buy FM sets. We don’t see figures in these stories about how many CB sets are sold in the US each year. That would be an indication of how fast change might happen. Wedon’t hear about CB, but I doubt many will spend on a new set.

    CB wasn’t intended as a hobby band, but cheap communication. The rules reflected that. 27MHz was not a good choice, but since TV got such a big allocation after WWII, there was little emoty space after WWII, at least until advances in electronucs made ever higher frequencies more useful, and indeed, more suitable. Hence the rules against skip always made sense.


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