Narrow FM, Anyone? HamRadioNow Episode 544 A: In many areas of the US (and the world), the ham radio 2 Meter band repeater segment is 'full' - no room for new repeaters. In some areas, there's not much elbow room on 70 cm, either. And it's especially been a squeeze trying to accommodate new DV mode repeaters. Even though their narrow footprint saves spectrum, our band plan structure, designed in the 1970s, is a bad fit. B: Most of our radios - those manufactured in this Century at least - have a mode button usually labeled 'Wide/Narrow'. Yet the only time we refer to them is when someone shows up on a repeater with low audio, and we ask if they are in 'Narrow' mode. That button could be the key, the answer to repeater spectrum problems in most areas of the country. Changing repeaters (and users) from Wide to Narrow, and finaggling the band plan a little (ok, more than a little), could nearly double the available repeater channels on 2 Meters and 70 cm, probably solving our repeater crowding problems for decades (or the next six months, whichever comes first). The Western Washington Amateur Relay Association, frequency coordinators for most of the western half of the state of Washington (the 'other' Washington), have decided that's exactly what they're going to do. They've already started, and they're giving themselves 10 years to get it done. There are a lot of details to the plan. They see user education as one of the biggest challenges, but repeater owners may have some work to do, too. Changing a 'modern' repeater to narrow can be as simple as a menu item in its programming, or it may involve a small frequency shift and duplexer trim. But not all repeaters are 'modern'. There are more than a few out there from the crystal-control era that have no provision for narrow operation. For them, it's replacement time (it's probably been 'replacement' time for a few years anyway). And not every user radio was made in this Century. I have a shelf full of legacy radios that don't know anything about 'narrow'. Fortunately, none are in my active radio arsenal. But they're still usable, and someone out there is still using that vintage. Have we finally disposed of all the radios that don't have CTCSS tone? The WWARA isn't proposing this as a model for the rest of the country (or the world), but I think it could be for most areas. I almost forgot - I'm here plugging a show! David W0DHG, Jim NO1PC and I welcome WWARA Chair Scott Honaker N7SS. Kenny Richards KU7M, and Steve VanWambeck N9VW to HamRadioNow for a lively discussion of the issues involved in this mass migration. HamRadioNow is also available as an audio podcast on most podcast players
Going narrow is not for amateurs.... 1) Commercial were FORCED by the FCC to go narrowband... 2) commercial radios include compandoring....Compression and expansion used for the narrow bandwidth to improve S/N Amateur gear does NOT have that and going to Narrow makes S/N suffer.... 3) NFM analog as used on commercial bands now requires 12.5k min channel spacing...10k will NOT WORK....15k didn't work out so well either....that why WWARA and others went 20k spacing in the 1980s when 15 splits were proposed....wideband noise out of a FM carrier causes desense at 15k spacing.....I PROVED that with MICORS, MSTRIIs, etc...you think the Chinese stuff flooding the market is CLEANER? AND their rcvrs can't even handle 20k spacing on RCV either!! I cannot drive by my 146.94 Quantar site trying to listen to my 146.96 Quantar 30 mile way without my TYT9800 getting clobbered by desense... you can't be serious thinking going closer will solve this issue.....As Scotty said, You CANNOT change the laws of physics... 4) if 2m is full, use 220 or another band....don't split the 20k channels to 10k....it WON'T work.....Texas adopted the 20k plan WWARA uses in the 1980s due to my proposal and technical findings after Clay, K7CR, made a talk about it at a TXVHFFM Society meeting..Clay told me after I did my part that if I ever moved to the NW, he would find a seat for me on the council there.... I'm sorry but going NARROW on amateur gear analog does NOT cut it in my professional opinion....50+ years in LMR, broadcast and Telecom engineering It WONT function correctly in amateur gear.....promote other bands OR use the existing repeaters that sit quiet 90% of the time... Chris WB5ITT Trustee W5APX Life member, former BoD Member and Frequency Coordinator, TXVHFFM Society
I appreciate your comments - good to hear from someone who was there 'back in the day'. I was a young pup in the mid 70's, hanging around the guys who formed the Illinois Repeater Council in the Chicago area. There, we opted for 15 kHz 'inverted', but that didn't last long before we went 'upright' but with spacing. I've been in the Carolinas since 1990, also 15 kHz territory. In that time, I've seen a total of ONE example of adjacent channel interference, a wide area repeater on 147.27, 20 miles SE from my base station, getting some sideband hash from a 147.255 repeater, also wide area, 60 miles W of my base. The receiver was a Yaesu 8900. My point is that 15 kHz pretty much works, and I listen a lot, constantly scanning every repeater in the territory at home and on the road. But, I appreciated the move to 20 kHz that EVERYONE followed when the FCC opened up the bottom MHz of 2 meters to repeaters, and we all started with on 220 (I'll never call it '222'). At the least, it eliminated the need for geographic separation between adjacent channel repeaters. You do mention not going to 10 kHz steps, and nobody is proposing that. The WWARA plan for 2 meters is for 12.5 kHz steps, which would require most repeaters to make a small frequency adjustment in addition to narrowbanding. And probably a duplexer tweak (which I'm guessing most of the duplexers could use now, anyway). They acknowledge the S/N issue. Hard to say how serious it will be in real world. I haven't heard talk of companding on commercial systems, but I don't live in that world. I scan commercial and public safety a lot, too, but 90% of that is now digital. The WWARA guys are seeing a lot more digital ham operation that I see here, and they said that the performance hit in NFM drives the move to digital. I suppose. I do have D-STAR, DMR, Fusion at home, mobile and HT, so I see all the activity. I do question the quality of receive filtering for NFM in even the current crop of ham radios. I mention on the show that I tried to do a simple test of S/N loss between my Yaesu FTM 300 and FT5D, but got stymied when the VOLUME CHANGED on open squelch noise as I switched the 300 from wide to narrow. Did they just boost the volume with no filter adjustment? I haven't dug out the specs to see if they say anything. I know that's what Kenwood did with the antique TH-6 handheld, because I asked at a hamfest. It was my first encounter with NFM, and I was curious. So I question that filtering, but I'm not sure how much of a problem it would be, even if the filters aren't that great. OTOH, the idea of desense in the SOC Chinese radios is something I see often between my AnyTone 578 and my ICOM, Kenwood and Yaesu radios. The AnyTone goes deaf with a pegged 'S Meter' in some places that the others have no problem. Not super-high RF areas, either. (I did observe that Yaesu 8900 working well on a trip back to Chicago, driving through downtown where all the TV, FM and 2-way stuff sits on a handful of tall buildings. The ICOM 2820 was mostly deaf there, while the 8900 was hearing suburban repeaters 25 miles away without trouble). I would be interested in doing another show with Frequency Coordinators from other areas reacting to the WWARA's plan, which they said is NOT proposed as a model for other areas. What are their current issues and plans for the future, especially accommodating DV mode repeaters on two meters? I would also like to find some more of the leaders from the 70's era you reference who created the band plans (especially the 600 kHz offset on two meters), then handled the explosion in repeater growth in several ways (15 kHz channel split, move to 20 kHz, etc.). Do you know any way to reach these guys? Are many still alive? I was in my 20s back then, and I'm 75 now. Reach me at my email listed on QRZ!
FM-N at 12.5 kHz instead of FM at 25 kHz has been the standard for 2 m in IARU Region 1 for many years and is also widely used on 70 cm. It works very well and has given us many new channels and enabled many new repeaters. I am surprised that it is only now starting to be used in the USA. By the way, 10 kHz FM-N also works very well, it has been used for CB in Europe for decades and in the USA I think since 2024 or 2023. List of Swiss repeaters: https://uska.ch/wp-content/uploads/2022/06/220622-USKA_Frequenzliste_Voice.pdf Map: https://repeatermap.de/?lon=8.1&lat=46.8 73, Peter - HB9PJT
Type "silent ham radio repeaters" into your search engine and explain to me why it's a good idea to spend the money to make these "silent repeaters" narrow FM.
From my term on the board of TXVHFFM I can say that the first thing to do is get rid of the paper repeaters. Give them 6 months to get it on the air or relinquish the frequency. Going to narrow splits just doesn't make sense in the amateur world. Heck, it didn't make sense to me in the commercial world except to generate sales for Motorola. GeorgeC W2DB Crowley, TX
The WWARA plan, presentations and FAQ are available at https://www.wwara.org/documents/narrowband-plan/ Scott N7SS
In a town of 5+ million and thousands of licensed hams, repeaters on VHF/220/UHF/900 are quiet. The technical reasons for narrowbanding are to pack more in to less spectrum. Part 90 went through this, one county near me stayed on VHF analog, narrowbanded (and spent over 2 million dollars replacing public safety grade infrastructure) only to find out: 1)-Audio quality on analog FM degraded 2)-Co-channel interference, especially when combined with older equipment with poorer selectivity, further degraded the system performance 3)-They ended up migrating to a regional 700/800 P25 network and ended up spending millions more anyway Why would amateurs even want to embark on such a journey? Most amateur equipment doesn't and isn't designed to perform optimally at 2.5Khz deviation and RX bandwidth. Never mind the cost of replacing legacy repeaters, which make up a good portion of the landscape, with narrow band capable station. Most of the clubs here including one of the most prominent and active 2 meter analog repeaters are GE MASTR IIs which I wouldn't even want to think of what it would take to modify for 2.5KHz. A solution in search of a problem.
Yeah narrow banding is needed because there's hardly a day that goes by where I can find a clear frequency to use on the busy, jammed packed 2m band.... (/Sarc)
Narrow is not needed in ham radio. We have more spectrum than anyone else. We need a better plan on how we are using it. Personally I like the idea of wider to accomodate say 4 TDMA talk paths off one machine. Or the ability to transfer a decent image while also talking. Also getting away from traditional modulation needs to be part of the long term goal. Analog and FSK modulation need to be phased out so ham radio can evolve. Each geographical area needs to set a number of machines per mode. That way there is equal accomodation. Define "full". There is a lot of problem at least to me, on repeater coordination. Its gotten even worse since we have so many digitial varients. While some places in the country can manage to put up a repeater for several digital voice modes, others cannot. Even in analog a lot of these machines sit idle most of the time. And linked repeaters are another waste of spectrum in most cases. Many just belch out activity that is not anywhere near local. When machines sit idle most the day I see no reason a second machine cannot co-exist on the same pair with a different tone. Just take aware their coodination complaint privilege. Some more SNP (shared non protected) pairs for lower profile/lower power machines are in order. As for the 31 flavors of digital problem and how to accomondate that.. New repeaters seeking coordination should be required to accomondate more than one digital flavor. This will encourge site owners to hook up a MMDVM modem. Coordinators need to take things like this into account when they create new polices.
In Kansas, at least, the movers and shakers that were still alive 40 years ago when I first became active on repeaters have since gone SK. At that time the debate was raging about 15 kHz versus 20 kHz channel spacing on 2m. Kansas retained 15 kHz spacing in the 146 to 148 MHz portion of the band and 20 kHz spacing in the lower FM segment of 2m including the once popular packet radio simplex frequencies. Mid-America Coordinating Council (MACC) was the big thing 40 years ago and some of the Kansas Repeater Council (KRC) leadership were active in its formation as I recall. Both are essentially defunct today. 20 some years ago KRC declared dues would no longer be collected. Later on the coordinator transferred the job to someone else and over the past few years I'm not sure if the last coordinator that I know of is even active. For Kansas it was declared that the Repeater Book Web site and app are the definitive list of coordinated repeaters. Perhaps the only real historical resources that exist are minutes of past coordinating council meetings or newsletters.
The fact that there are so many repeaters that are hardly used is because we as HAM like to set up systems. We do a lot of things that we enjoy and like to experiment. I think that's good. I think it's wrong not to give new HAMs the opportunity to set up their own repeaters. Anyone who wants to experiment with it should have the opportunity. The use of narrow bandwidths provides this opportunity. I can't understand why anyone would say that narrow bandwidths don't work or cause interference. My experience says it's not a problem. Certainly the frequencies have to be planned sensibly so that two neighboring repeaters are not only 12.5 kHz apart. If you distribute the frequencies cleverly, there will be no interference, even if an OM forgets to switch his device to FM-N. 73, Peter - HB9PJT
There are far too many repeaters, and they are mostly built for vanity reasons. Currently. about 400 repeaters are known to exist in Sweden, about evenly split between 144 and 432 MHz bands. Almost all are uncoordinated, with a possible exception for those built in the 70s and 80s, when a separate licence and coordination by professionals at the Government spectrum authority was required. In total, there were between 45 and 50 repeaters 40 years ago which was entirely sufficient even when VHF/FM activity was at least one order of magnitude higher. I see no point in constructing completely redundant repeaters which are silent 99.99 % of the time. The best way out in my opinion would be to reinstate the separate licence and professional-level coordination requirements.
