intermod

I have operated amateur DMR since 2011 and legacy analog repeaters since the 1990's. What I increasingly find in amateur are many abusive people with closed minds that lack loyalty to friends. Also very cliquish. They want to consider amateur an exclusive club...no thanks. I find those in GMRS - many very new to radio - as more open-minded and less abusive (except for here . ) I am guessing that of all the people that want or need a radio, likely ~90% will never get their amateur license. So we miss out on all of them. GMRS is a great service for the vast majority of these people. The familial license is just the right amount of regulation to keep business and large incompatible organizations from monopolizing it and running legit GMRS licensees off. But the other nice thing is less content moderation by the government. I can actually conduct my small business communications over GMRS legally. The ability to hand a radio to another family member for quick comms is also great. Lets expand GMRS capabilities, not cripple it with inflexible rules.

Oh - you are referring to repeater-capable radios. Most OTS radio don't have repeater capability because its way too complicated, as you say. Just allow them to change the color code - done. There are only 16 to choose from. The same way an analog radio user would change CTCSS/DCS codes if the same thing happened. No different. Play nice - agree. That is the general guideline. What about BCLO and dual-mode would not be a way to play nicely? Also - I just considered you may be the kind of user that operates carrier-squelch. Digital signals are more annoying to listen to (but they don't cause more destructive interference than analog). If so, CTCSS/DCS can take care of that. We have to run CTSCC/DCS full time in this area so that we don't hear all the commercial bubblepack and digital traffic. I just create a channel for each repeater I want to listen to (with CTCSSS/DCS) and scan them. The bubble-pack radios come with CTCSS/DCS enabled so they won't know any annoying signals even exist.

I don't ever start nasty comments; I only reply to them. But I try to add some constructive comments that might help certin individuals. Agree that the vast majority of GMRS radio are "purchase off the shelf" (OTS). But once the FCC permitted repeaters, the radios needed to be a bit more complicated. Mobile radios were then available, and these are also a bit more complicated overall. So clearly the FCC did not intend this to be only OTS. They intended both. All I am saying is why handicap users who are willing to put the effort into it? The off-the-shelf radios will always be available for the majority of users. Even digital radios can come in bubble-packs, pre-programmed with all the required digital settings. Then the user does not even need to care.

Has anyone considered asking the FCC to permit digital direct-mode (simplex) such as P25, NXDN, DMR, on the 462 MHz channels? Some posters in other threads have been concerned about digital repeaters causing more interference than analog ones (although nobody has yet been able to show how this occurs). So why not allow it on the eight 462 MHz channels? We already have many people using digital in this manner daily here anyway - listening to them tells me they are commercial users. Digital radios are less susceptible to interference from analog or other digital signals, so this would be of great benefit in areas subjected to all the commercial 2-watt bubblepack radio traffic. Range would be limited so it would not disrupt a significant number of analog users - particularly those using CTCSS/DCS. I am not suggesting requiring anyone to use digital - it would just co-exist with legacy analog radios and be another buying choice. This would apply to both portable and vehicular radios. They would not be permitted to transmit on the 467 MHz repeater input/uplink channels.

I had a few DMR applications delayed back in 2016 for exactly that. One key reason that DMR was causing more issues was the repeater duty-cycle was higher (part manufacturer default settings, part traffic-related, and use of constant GPS messages). They had me reduce power in my case, but they were also considering directional antennas in others. But in the seven years since it seemed to reach an equilibrium and everyone settled in. The vast majority of systems that are actually in use here on UHF are digital now (maybe 80/20 DMR/NXDN). So you all-caps comment appears incorrect and a bit out of date. It works, but Part 90 is also a different environment. That is why I suggested using BCLO, dual-mode radios as GMRS is a different beast. But great ideas. Maybe require new DMR repeaters to run lower power and/or use directional antennas. G

From experience over the years it seems the FCC's main concern about mixing any type of digital in is it impacts the "listen-before-talk" (LBT) etiquette and the ability to work out interference issues via voice (analog users would not be able to hear the digital users). Of course, analog users could not hear the digital users' callsigns, but they could hear the repeater callsign that is always transmitted in analog. LBT can be solved today by requiring the digital users to operate dual-mode capable radios (ones that will decode digital or analog on the same channel automatically). Hytera, Anytone and others already have this feature. Or require Busy Channel Lockout (BCLO) be used on the digital-capable radios. So the manufacturers of digital-capable radios would be required to build one of both of these features into their products - make it a type-certification issue. The the other direction - i.e., analog users causing interference to digital users - is not an issue as most all digital radios are capable of receiving analog. So they could get callsigns and contact analog users that are causing IX. Or - place a requirement on the digital user that they must accept interference since they are the new kids on the block.

It will add a number of choices to the service, and to some it would cause complexity. But its complexity a consumer chooses to take on or not. Buy analog if you like that - and you could likely save some money as well. I never mentioned encryption, GPS, etc. as there is no reason that the current restriction on these would need to change. RAS can be accomplished today through various schemes in analog as well, so this is not specific to DMR. FB2/4/6 remain an option as you said before. Gortex2 said "Very few places in the US have issues with congestion so I don't see changing a service because one city or state has an issue.". So in reality maybe the FCC pushed us in the right direction by allowing site-specific authorizations for DMR. A federal rule change is quite an undertaking.

Apparently you did not understand my post. I once had reading comprehension challenges but was able to overcome them early in my childhood. I can contact you offline and make some recommendations if you wish. Should we dumb down consumer products for the lowest common denominator, or give consumers a choice?? Did you not agree that there (at least) two classes of users on GMRS? Are you thinking that Amazon, Walmart and others would only offer DMR radios? Why would that be?

But we have had two classes of users for almost 30 years - the "common folk" or bubblepack users (all direct-mode/simplex) and the more professional users that operate repeaters. 100% of our DMR users figured out their radios within about 1 day when first getting on.

Is this problem limited to one city or state? Or maybe neither of us really know. Are you suggesting a "one size fits all approach" is the only way? The FCC has created a list of "major metro areas" in Part 90 where different rules apply. Why not apply this same concept to GMRS? It is highly unlikely that additional radio channels will be allocated for GMRS in specific regions. So it seems logical that the best approach is to make better use of what we already have. Digital provides 4X the capacity within the same spectrum. It is not clear if this will actually increase perceived interference or reduce it since far fewer repeaters would be needed to support the same number of users. For example: I have two separate user groups operating simultaneously on a single DMR repeater today, as it provides for two simultaneous channels (slot 1 and slot 2). If I were to lose the DMR license for this and have to go back to legacy analog operation, I now need to build a second repeater and use yet another GMRS channel for that second repeater. I suspect this might increase interference to those on the new channel......

Seems to be many posters that are complaining about digital but do not come up with any viable solutions to the current reality in some areas (congestion due to very large influx of new users in a short amount of time). Creative solutions welcome.

If you like animals, carrier pigeons are great, too.

Lots of it going on. I have not identified that one rule...maybe I will dig around. The Commission routinely grants licensees requests to split the channel down the middle and licenses them to separate entities. Presumably they have waived that particular restriction. G

So, can one link Part 22 spectrum (private or common carrier) to GMRS legally? I cannot seem to find a restriction to this (just an idea, if we lack GMRS spectrum but have Part 22 available in an area). This would not be permitted on Part 90 or other LMR spectrum.

Good info. The Atty. I spoke with suggested as much.

Bingo...

I cannot disagree completely. In general, most all of the amateur systems sound on the edge of garbally, shrill, or muffled (Brandmeister) Our GMRS DMR repeater can also sound this way, but it depends on the transmitting user's radio quality. The utility DMR systems sound just fine and the vast majority of users like it - even the older employees. After working on many DMR systems, my confident conclusion is: - DMR audio can become quite good depending on the manufacturers microphone selection, audio processing on both TX and RX sides; and - Using the the same radio manufacturer throughout the network; and - The tonality of the speakers voice (some voices sound better on DMR than others; its also biased against females) - The RX speakers make no difference. The best I ever heard was when a $1500 David-Clarke headset was used with an XPR7550 portable radio. Equal or better than a strong wideband analog signal - and I am quite picky. This configuration met all the above conditions, however.

We also have some idle ones in our area I contacted the FCC a month ago to see how one might licenses them. An attorney confirmed that an auction is required. And none are currently planned.

Totally agree. These remain like gold, but we have been using them for trunked control channels, and then combine them with Part 90 channels, where we cannot attain FB8 status. The Part 22 channels are wideband (like GMRS) and can support two DMR channels like I proposed on the original post. I am also experimenting with placing three DMR channels in one Part 22 (-6.25 kHz, Center, + 6.25 kHz), with geographic separation between any 6.25 kHz adjacent channels.

Are you suggesting that people in areas that were just ravaged by wildfires are irresponsible when they install a new repeater to save lives?

GMRS is quiet much of the time here as well, other than the simplex traffic from business, or when there are major fires. The "congestion" issue I mention is related to time-of-use. Our groups, and those on other repeaters on the same channel, often want to use their systems at the same time. Due to the terrain here, our portable radio users can get stepped on from users of other systems operating mobile or control stations at high-elevations, even 80 miles away.

Agree - it really has to work this way.

Works great. Its been done since 1995. You can place two repeaters 12.5 kHz (or 10 kHz) apart on the same antenna and duplexer by using a hybrid-type combiner. Receivers can use an amplifier and two-way splitter. 12.5 kHz narrowband is less efficient unless you use the freed-up spectrum on either side of the narrow signal, right? And you can't place two 12.5 kHz analog narrowband signals on a GMRS channel due to overlap. In fact, analog narrowband is an even a worse loss because it reduces your coverage (same affect as reducing your transmit power by half) and worsens interference susceptibility by 6 dB. This is one reason digital was created (other than to sell more hardware...).

Here is another reason for placing two DMR repeaters within the same channel: We have two repeaters, 20 miles from each other, on the same frequency (using different CTCSS codes). There is significant overlap, so they cannot be used at the same time. We could use them at the same time if we replaced the two the analog repeaters with two DMR models, with one was moved down in frequency, and the other up in frequency. So they would effectively be operating on two different channels and not interfere with each other.

One example from one of our repeaters. Three different groups wanted to use one repeater (a general group, a family ranch & CERT). Using analog, we gave each group their own CTCSS code so they would not hear the other group. This was really needed as many were turning their volume down or radio off to silence the chatter from the other groups when they shared a single CTCSS code. But often enough they needed the repeater at the same time (weekends were the worst) and as expected, started walking on each other. Training on using the monitor function or watching their busy lamp was attempted, but as always, this failed. Using busy-channel-lockout (BCLO) was not possible as many radios did not have this feature, and the ones that did were locked out often due to traffic from commercial users and/or interference. They all wanted to buy a different model radio..so we could not dictate this. Repeater site rent is expensive, so each could not afford their own repeater. And, it would have required 3 of the 8 GMRS repeater channels for each to have their own. But only one GMRS channel was available (our existing one) - the other 7 are used nearby. With the proposed approach, each group could be assigned their own private slot and use it at the same time (with one slot left over). Thus, placing two DMR repeaters in the space of one analog repeater would solve this problem, without using more GMRS channels. And we would have one slot unused for yet another group. Or maybe we dedicated that that for text-messaging or private calls.