WROZ250

While I agree with most of what you said in reference to the interference/jammers, what is your beef with Amateur Radio? Hams (the vast majority anyway) do not think they can talk on any channel they want. Where you getting that from??? Indeed, one can find such imbeciles (who think they can transmit anywhere, anytime) pretty much in any radio service/hobby. Such stupidity by a couple of miscreants isn't exclusive to people who also happen to have a 'Ham' license. In any event, if there is one thing in this forum that gets to me from time to time, it is this constant ideology by a few that 'Hams' are somehow 'bad people', idiots, 'snobs', whatever (take your pick). I would also point out that there is a large percentage of GMRS users on this forum who are also 'hams'. I guess I just don't understand this constant condemning of that segment of the radio hobby? ?

FWIW, I have two versions of this radio (actually there are a few of these under different labels) the DB20G and the AT779UV, and they are identical in every aspect save for the name on them. Indeed, the default startup on DB20G will display 'Anytone', as I'm told the other labeled units do. Depending on who one purchases the radio from seems to dictate what the factory range is. I purchased the AT779UV from Amazon as a 'GMRS' radio, but it came defaulted to Ham Band (with restrictions). Ironically this same radio has a Part 95 FCC ID. The latter I am less concerned about in any event. Regardless, at $100 (average) the radio is a good value for the money even for 'CCR'. Besides, it has a "FUN" button! LOL! ? That said, there are a lot of used Part 90 radios on the market that can be had for about the same price. ?

It might be a version thing and/or which range you selected. If I select the wider frequency range it does transmit 'everywhere'. The model I have offers several choices of ranges, one of which is specifically the US amateur bands and nothing more. That range is the one that will not transmit out of the specified band(s). Nice radio for the money in any event.

Actually, if you throw the radio onto the bench, a quick check will show that the microphone line doesn't even go active until the MDC/PTT ID has been sent as the radio (or rather the PTT ID circuitry) accounts for the power delay before sending the PTT ID. At least it does for Motorola radios. Worse case scenario is that the first syllable of your voice gets clipped if you're a bit quick to speak, which is the point of the PTT sidetone. You wait for the sidetone to complete before speaking. ?

It isn't about killing ideas or censorship, it is about a specific topic that has been beat to death so many times and on so many sites, that has become an annoyance for a lot of people. I would point out again that even the proponents of the 'national travel channel' can't seem to get it going even on a local level. This topic is a proverbial 'broken record'. Honestly, I think it keeps coming up because the OP didn't research the topic before posting, or just enjoys creating controversy. Perhaps the best thing to do here, is rather than even comment or suggest the topic be moderated, is to simply ignore it, lest someone take a dissenting view and extrapolate it to the Nth degree to suggest it means something far more sinister. ?

Back in the early 1970s, in the great lakes area, the truckers were on CB channel 11. I think the whole channel 19 as a road channel thing grew out of people hearing that dip-shit song Convoy, like a lot of the CB boom. Before the 'boom' (and that stupid song) in the mid 1970s there was usually 23 channels of mostly static and 5W AM with a modest antenna was good for many miles (without 'skip'). CB Channel 19 was never really any kind of standard, and the 'road channel' was more of a case by case geographical thing. As far as GMRS road channel... IMHO, if a 'road channel' was something that was ever going to become popular, it would have happened years ago with 462.675 and CTCSS 141.3 when it was the suggested channel. GMRS is way more popular than it even has been, but it's just not something that John Q Public is going to have in his car and use on vacation or traveling to grandma's house for Christmas. Indeed, the popularity of CB is way down all these years later, it has become a borderline wasteland populated mostly by die hard 'hobbyists', most of whom are using SSB these days, foul mouth truckers, and nut jobs running a couple thousand watts talking to nobody, none of these demographics follow the rules. Compound that with the complications of GMRS of having to know how to program/change CTCSS/DCS codes, programming a radio, etc.. none of which has to be done with a CB radio. It might sound like a nice idea to some, but it is just not something that will ever happen. The nature and limitations of GMRS... it doesn't make sense and, as someone else mentioned, groups that do need to coordinate their communication have long since settled on a (GMRS) channel and/or other radio services and/or technologies. John Q Public.. you find them down on the bubble pack radio channels, usually channel 1 and what ever tone (if any) it was on when they pulled it out of the box. I doubt that any of the current people calling for this could even get it rolling in their local area, nevermind nationally. All that said, this is such a redundant and beat to death topic, perhaps the admins will ban it going forward. ?

This Topic, Again?? ?

Not to mention there is only one 'top spot' and, not every user requires a full omnidirectional pattern. However, many (commercial) tower sites have one massive antenna at the top spot and feed it through RX multi-couplers and transmitter combiners, for customers who want, need, and can afford the 'top spot'. Side arms, in addition to the previously mentioned reasons, are a way to generate even more income to the site owner (more customers). None of this necessarily has anything to do with range, although height rarely is a bad thing. While coverage/range can be predicted, anything short of that is speculation (it depends). Even coverage prediction tools have their limitations. ?

I Sorry, didn't see the reply by @MichaelLAX Follow his procedure. It's not a bug. By default, there are a finite amount of memories that permit transmit in the GMRS mode. Do yourself a favor. With the radio off, press and hold V/M button and power the radio on. You will get a menu of configurations/frequency ranges. If you select the 400-480 range (or whatever roughly matches that) the radio will revert to that setup and all memories are usable for TX/RX. Your existing memories will be reset to new defaults, but assuming you only want GMRS, you now have as many usable memories as the radio offers. The same is true for the AT-779UV and other clones of that radio. FWIW, this 'mod' is completely reversible, at least it was for all of my radios.

Oh, sorry. I don't seem to have access to the alternate/magical FCC database. Just the same one everyone else uses. As far as the other stuff, everyone has their right to an opinion I suppose. ?

Yeah, programming DMR radios is definitely not for the inexperienced (or the impatient). LOL!

Wow, so because you, as a former ham (no current or former amateur license on record), apparently had a bad experience, you condemn an entire radio service.

The Spectra was the last radio that was given to field support specialists to 'beat up on' (in real world use) in an effort to uncover any serious issues, before it became a released product. That use to be a common practice in the Bob Galvin days of Motorola, and so the Spectra was perhaps, one of the most reliable radios ever produced. Not saying later model radios are of lesser quality, only that the Spectra was the last radio produced when 'do it right the first time' was an actual practice within the company, and not simply a 'slogan'. Bottom line, it was and remains a great radio! ?

I agree! With the limited number channels offered in GMRS. DMR could actually (if implemented) double the number of channels due to the dual time slot capability and, still remain compatible with analog users, so nobody gets 'left out in the cold'. I don't see the FCC doing this anytime soon (if ever), but we can hope, right? I think the issue boils down to such technologies taking GMRS beyond the scope of what GMRS is/was intended to be, at least from the FCC perspective. This too, is a topic for another discussion. ?

That is a very valid point. On one hand, as someone else mentioned, there appears to be no part 95 radios that have MDC in them, whereas some (not all) part 90 radios do. Sort of the same issue for ham radios. I don't know of any radio manufactured exclusively for amateur radio that includes MDC, yet hams are free to use part 90 radios whereas GMRS technically can't use them, even though it seems to be a common practice. So in reflection, it does beg the question of legality in both services and so perhaps I was misinformed about GMRS. Where I saw the difference was that hams can build their own radios and GMRS users can only use manufactured (part 95 type accepted) radios. I asked the original question because while I am certain that MDC is not permitted on ham, now I am back to questioning the legality of it on GMRS. (Oye!) The rules almost require a doctorate degree to understand, which leads to multiple interpretations. Combine that with the constant practice of people thumbing their noses a the rules (ham and GMRS) to the point where it becomes 'common practice', we find ourselves at the point where nobody really knows what is and is not legal. My interpretation, where ham radio is concerned, came from a legal explanation when I was still in 'the business'. At the time, GMRS was not not even on my mind and the conversation was specifically about the use of (commercial) digital protocols by hams. I agree with you in that if you look at the issue from the encode angle (virtually/effectively encrypted), it would be illegal in both services, save for the fact that there is no attempt to skew or hide the main information being transmitted. So for myself, I'm back to the 'adhere to the most restrictive interpretation of the rules' mode. That said, like the use of part 90 radio in GMRS, I don't see either user group who currently use it, ceasing the use of MDC until/unless confronted with a violation notice. If that happens at all. Doesn't really bother me in either radio service, indeed I rather hear people sending a short MDC burst than a string of DTMF tones. Personally, however, I simply don't operate in 'grey areas' where the rules are concerned. But that's just me and I'm not suggesting anybody stop if they do. To each their own! ?

Well this is where one gets into a grey area... sort of... But you nailed it on the head. MDC by default is not encrypted, but it is encoded within a proprietary protocol. A protocol which, being proprietary and restrictively/non-published, is unavailable for use and/or arbitrary decoding (deciphering?) by, in this case, amateurs. As I alluded to previously, MDC isn't simply PTT ID and/or private call, the full data protocol is extremely powerful and feature rich. Antiquated or not, MDC is capable of things that few (if any) amateur digital modes, even some commercial data protocols, are capable of providing . Perhaps that is why it has not been release as an open standard (admittedly speculating there)?. So while it isn't technically encrypted, it effectively/practically speaking is, or might as well be. Were Motorola to release the protocol to public domain, making it 'open' to all, there is no reason it would not be completely legal for amateur radio. However, unless something has changed, MDC is not an open standard. That, is how I interpret the restriction/prohibition under the Part 97 rules. There are protocols (such as D-Star and P25) that have some proprietary features within, however, the the protocol information is not restricted, hence the availability of, for example, hot spots and dongles, most of which support open protocols such as P25, Mototrbo (DMR), D-Star and a couple others. As far as the FCC is concerned, I do agree that under 'normal' (what's normal these days?) situations, the FCC would enforce the restriction. The reality is they rarely enforce anything but the most serious offenses these days. That, however, is an entirely different topic. Again, for those who have not been paying attention, not talking about GMRS legality, only Amateur radio. My original question was answered where GMRS is concerned. ?

My question had to do with GMRS use of MDC. However, at the risk of getting into a debate, I'll answer your comment. First, it has nothing to do with modulation and bandwidth, etc... MDC is prohibited (on ham radio) because it is not an open standard. MDC is proprietary, Motorola created and owned, and so for every radio manufactured that includes it, that manufacturer pays a licensing fee that is (one would assume) included in the cost of each radio. For example, were you to build your own radio and wanted to include MDC signalling, you would need to ask Motorola for the specifications of the protocol and (like their other software licensing) have to pay them for the information and the use of their technology. Also like their software licensing, it is highly unlikely that such a request would be granted to an individual/end user. With the above noted, because an individual cannot legally obtain access to the details of the protocol (MDC), and/or use it in a design, it cannot be used in amateur radio. All that said, I am more than aware that there are hams using MDC signalling and that a lot of details of the protocol have leaked out over the years, to the point where one might be able to build a unit and/or write some code to make use of it. However, to the best of my knowledge, it's remains Motorola proprietary and so would remain a closed standard. So how are these people getting away with it? My opinion is that #1. when it comes to rule violations, it's a minor violation. #2, the FCC rarely goes after serious offenders so it's unlikely something like this would ever be pursued (much like the part 90 vs part 95 radio issue). The fundamental difference is that Ham radio and GMRS are two different radio services each with it's own intended purpose, rules and restrictions. Hams are permitted to construct their own equipment, GMRS operates are not allowed to do this. Ultimately GMRS operators are, in many ways, just users and so as our equipment is manufactured, we are generally free to use whatever technologies come with those radios (rules notwithstanding). Even then, the GMRS rules have a lot of caveats in regard to what kind of things we can put into the microphone jack so to say. Hams have very few technical restrictions beyond ensuring bandwidth use and clean signals. What lead to my original question was that MDC seems to still have a lot of debate going on between proponents of its use in amateur radio and those like myself whose understanding of legal operation (when it comes to Ham radio) leans to the restriction on the use of proprietary technology of any kind. Basically, if Joe ham cannot legally build a radio that includes technology 'X', then technology 'X' cannot be used in amateur radio. MDC is one such technology. Many will point out that there are other protocols in use in amateur radio, some of which include technologies that are proprietary to the manufacturer, D-Star for example (Icom). Nevertheless, those protocols and the licensing of them to end users and equipment manufacturers are available. While an end user likely isn't charged a licensing fee, another manufacturer would be. That again, is the fundamental issue. The protocol must be legally available for the end user in amateur/ham radio. While Mototrbo (DMR) and P25 are Motorola creations, both protocols are openly obtainable, indeed published. P25 via/through APCO and Mototrbo is based on one of the ETSI standards. My understanding of such restrictions is based on a long career I had as an engineer with Motorola. That said, It could be, as @Radioguy7268 mentioned, it is possible that patents have expired on MDC. It is admittedly, a somewhat antiquated (but in its full implementation, extremely powerful) protocol. Indeed, it may be that MDC signalling (not the full protocol) is legal because there is little in that subset of the protocol that could be considered as a way to concealing intent or otherwise be considered as a 'cypher' (encryption), which is not legal on ham or GMRS. I don't fear the FCC, but I do like to operate legally as much as possible, and after years working in the communications field, my experience with FCC rules is that one should adhere to the most restrictive interpretation. I don't feel my understanding is simple opinion, but take it as such if that helps. My original question was specific to GMRS and was answered, so I'm done with the issue and have no interest in debating it. Indeed, for the purpose of this GMRS forum any such debate is irrelevant, because MDC is legal on GMRS! All that said... I do apologize if my explanation seems to carry some tone, but I am admittedly upset because I posed the same simple question on a different GMRS forum and the sysop/admin of that forum threatened another user with removal for disagreeing with him, even resorting to a personal attack before threatening removal. Yeah, an admin, over a technical discussion!!! WTF? I enjoy (some) of the discussions that occur here, but really guys, if anyone feels they are personally, nevermind violently, offended because someone has a different opinion, then perhaps that person should stay out of the frey (IMHO). So by all means continue to discuss this one if you must. Just do it with respect and civility. To each their own.

I feel kind of stupid asking this question, but I'm genuinely not sure of the answer. I know MDC signalling is not legal on amateur radio, because it is a proprietary (Motorola) protocol (e.g. not an open 'standard'). However, I can't find anything in the rules that prohibits its use on GMRS. Legal or not legal? (cause I'd really like to use it). I'm leaning towards it being legal but I'd really like some feedback on the topic Thanks! ?

Same reaction for suggesting GMRS coordination.. (LOL!)

Well, that sort of makes @Radioguy7268 case. If somebody is willing to pay a 3rd party 400% over retail, then they kind of deserve to get fleeced. Still, I don't see the 'authorized retailers' selling at MSRP, so they too are profiting to some extent. You are correct however, It isn't illegal, but it is horribly unethical. Either way it's a bad situation. While I don't have a stockpile, I do have enough for the projects I am working on and, while I would have liked to have had a few more in hand, I simply cannot justify paying even the best prices today. Given that, I have been looking at other SBC options if not reusing an older PC with Linux OS. I too apologize for the off track pull on the thread. ?

In this case it is (IMHO) a ripoff. Raspberry Pi in the UK, still shows the device (as @wrci350 points out) with a specific MSRP. It is the resellers that have jacked up their prices to close to 400% in some cases, and in doing so have created the shortage. At the same time, @Radioguy7268, you are correct in that there is nothing wrong with doing that (legally). To that point, by doing this, these retailers have taken an otherwise affordable product, targeting hobbyists, and put it financially out of reach of many of those same hobbyists. In the end, 'Economics 101' is probably going to come back and bite these hording, profit taking, retailers in their proverbial asses as sales will drop. This will happened because those targeted hobbyists will look to other options, and so by the time this BS crisis ends, interest in the Raspberry Pi line will have evaporated. In many ways I blame the Raspberry Pi Organization itself. If they really believe their product should retail for under $100, then why don't they sell it directly at that price to end users? Indeed, selling it only through retailers who are clearly capitalizing on a bad situation, kinda of makes them look as guilty as their 'authorized retailers'. If they were genuinely honest, they would either (as many manufacturers do) restrict the 'Authorized retailer" to a fixed price. If it was costing them more to make the product, they why not be honest and raise the MSRP to what they believe it should be. The bottom line is at that the Raspberry Pi is no longer an affordable alternative to, for example, a Linux PC (other than size perhaps) and, there are other (previously less popular) small board computers on the market that aren't selling at 400% over MSRP. So if the Raspberry Pi organization doesn't take control over its 'authorized retailers', then they are only hurting themselves in the long run. Yet another great idea ruined by greed. ? Just one opinion...

N = non-inverted I = inverted Referring to the digital polarity of the DCS signal. Interesting enough, there is a mirror effect in that many inverted codes will have no inverted equivalent. So even though there are over 100 DCS codes, in reality there is only half of that as again, inverted codes can have bit patterns that mirror non-inverted codes. https://forums.radioreference.com/threads/inverted-cdcss-dpl-conversion-chart.8261/

Sounds like what you are looking for is some kind of 'hot spot'. I think a bigger issue you might be running into is finding a GMRS network that will accept a non-repeater (i.e. Hot Spot) connecting to their network. Many, including the MyGMRS network only allow repeaters to connect. That said, I do know such system are out there because You Tube has all sorts of videos with people building these things. Unfortunately most of these are running asterisk (a.k.a A-star or Allstar) or some variation of it on a RPi. Really disgusting how much the price of the RPi has gone up. ? I could be wrong, but I believe there is a version of asterisk that will run under Linux on a PC. Good Luck in any event.

You might want to look at the physical requirements for a self supporting tower, specifically the concrete base/foundation and your city ordinances. I found the price of concrete required to make a proper base exceeded the cost of the tower itself by a factor of 4, more if your municipal ordinances requires a contractor do the work as a condition of acceptance. Just an FYI, do your homework before plunking down your money on something the vendor will not take back.

Just a thought, but perhaps a way around the store forward over the air limitation, would be for a base station (or similar S&R EOC setup) could receive and relay the data to rescue personnel via an alternate (non MURS) network? Dunno, bit of a PIA to deal with it all from my perspective. But... ?