intermod

Does the FW need to be removed, or can he just program a conventional channel in them and go with that? Or does CP preclude programming a conventional channel?

Good recommendation when using those model for repeater operation. But if/when the transmitting radio fails, just swap the radios around.

See attached model number chart. These are 450-512 MHz models. These will work on GMRS but not amateur. I have many XPR4550 radios and a few 5550. They have superior receivers from a susceptiility/overload perspective. They are perfect radios for creating a repeater. Their accessory outputs are easy to program. They have a design flaw where their accessory port output of low frequency CTCSS codes (below 114.8 Hz) or DCS are poor. But that is fine. Not sure about cables. XPR 4550 Model Number Chart.pdf

I will also add that if an analog signal comes along and happens to be as strong if not stronger than the digital signal you are trying to listen to, the analog will either make it impossible to hear the digital signal or you just wont hear it at all.

The General Welfare clause amounted to no more than a reference to the other powers of the subsequent clauses of the same Section. How could this be any other way? If "general welfare" was interpreted to mean virtually anything, it would destroy the entire concept of limited (federal) government and justify expenditures in any field. Limited (federal) government was one of the primary goals of the Founders. However, I get that this has been the interpretation for a long time (re: Butler Case, 1936). I wonder if this has had any impact on our national debt?

Uh - you followed *me* here. Please add me to the list. OffroaderX can't be too bad if he studies the Constitution. Did you have any comments on what in our Constitution authorizes the FCC to exist?

Excellent term. Agree - such topics are truly meant to trigger g-m. Its so effective.....

I though this was just someone messing with the camera - but then I heard the voice modulation in the recording....cool. Further - Imagine if the Great State of California tried to manage radio spectrum.

Agree that some bands that are used over state lines need general administration - or those that involve life-safety. Spurious are the same as non-spurious: if they don't cross a border, then its not their responsibility. This is not a binary choice (regulation versus free-for-all). Each state may have unique wireless needs that they could address - interior to the state - away from the edges - that would add flexibility.

Correct, but any law in violation of the Constitution is null and void on its face ("pretend legislation").

We simply use the magnetic field versus the electric field as a measurement basis. It falls off much faster with distance.

Does anyone know what gives the federal government the right to get involved in local wireless communications - or their justification to even exist as an agency? I can understand that they could justify involvement in long-distance HF, and any wireless signals that cross state or international borders (i.e., commerce clause, etc.). But I operate on UHF where the signals don't cross any state or international border. Their authority to exist is not defined in the US Constitution (of course). Thus, this responsibility should either fall to the State, or the People.

Lscott's proposed plan using a narrow NXDN or dPMR type emission (~4K00 - if am I correct) is absolutely the easiest way to approach this when we have a federal bureaucracy to deal with. And the manufacturers will jump all over digital in any form to sell more equipment or differentiate their products (ant least temporarily). So he would likely have both GMRS licensee and manufacturer support. And all the hate that comes with mentioning the D-word. As we have many mountains here in our Northern California area (repeater signals travel great distances), GMRS interference and capacity issues can only be dealt with by addressing repeater use. So that is why I focus here. Agree that getting more spectrum is unlikely. If we eventually have to discontinue use of DMR, the two main users groups (on Slot 1 and Slot 2) will now have to share a common (single) repeater channel, but they are more likely going build a second repeater on a different channel, in an attempt to get the same level of service. This will create as much or more interference than the single DMR repeater did before and eat up more of our limited spectrum. So these things need to be looked at broadly to really understand the overall picture. The horse has expired.

I am sorry to have triggered you. So I understand - are you suggesting I try amateur radio?

See attached. This is the key table for determining what the required C/I ratio is for a given voice quality and technology. Much of the other data was use to generate this table. DAQ3 column is what should be used from commercial and GMRS. For others who have not used this, it shows that: 1. Analog FM ± 5kHz (25 kHz) requires a Carrier-to-Interference (C/I) ratio of 17 dB (e.g., any interfering signal, regardless of type, must be 17 dB weaker than the signal you are trying to receive for good voice quality) 2. ETSI DMR 2 slot TDMA (AMBE +2) (12.5 kHz) requires 14.3 dB This indicates that DMR and other digital signals can tolerate more interference than Analog (2.7 dB greater interference tolerance in this case). This table also indicates why you really don't want to use analog narrowband. Narrowband analog (Analog FM ± 2.5kHz (12.5 kHz)) requires a C/I of 23 dB, which is 8.7 dB worse than DMR and most other digital technologies. Anyone that has used narrowband has already realized this. So - if the FCC ever proposes narrowband analog, I would hope they would also allow digital so we could maintain the range and performance of our radio systems. TSB-88.1-D-Annex A Table.pdf

I had not seen NXDN programming before. Was is the "Common ID" field? Is that the "RAN"? Completely agree that this is easier than DMR. I hope some of the the DMR settings (not the slot, CC, Talkgroup) that nobosy ever plays with will get accepted and not be present eventually. But also, Kenwood makes things much easier compared to the others. G

MURS does not permit common digital voice modes like DMR. See § 95.2771 MURS emission types. Another reason why GMRS is the right place for digital. But thanks for suggesting the idea. I had forgotten whether MURS allowed this or not. But both MURS and GMRS permit DMR, P25 and NXDN data, such as for texting. Or maybe GPS...not sure about this one though. Retevis made one last year - could not remember the model. DMR on GMRS, but only for texting. Analog voice.

Is this a digital problem or a poorly-design analog radio problem (e.g., is the analog radios CTCSS/DCS decoder to apt to false on digital noise)? We have run dual-mode on our repeaters and have not experienced that - except with a few Boafengs that were really low-end. We were able to false those decoders by just talking on analog - they would open their speakers intermittently. Yea - the thing that sucks is that all the digital modes are incompatible. But do you think that the world is headed towards a digital radio nirvana (one standard - all compatible) or is the trajectory in the other direction?

Correct - GMRS does not have that requirement, but it more broadly states that users should avoid interference and cooperate. But the "listen-before-talk" (LBT) concept generally remains. I found that the vast majority of Part 95 analog radios lack a Busy Channel Lockout (BCLO) feature - and in practice, nobody uses or remembers how to use the Monitor button. And many new bubbleplack radios come with CTCSS/DCS enabled on their receivers. In contrast, all DMR radios have BCLO, and many have dual-mode capability that allows monitoring of digital or analog signals on the same channel. DMR repeaters also have BCLO built in, and you can manually fine tune the lockout threshold. Few analog repeater ever had such a feature. So the DMR radios and repeaters are much better at channel-sharing and protection than analog radios.

Of course, but we are comparing analog to digital. Your statement is a bit too broad. Empirical tests have proven that for a given digital voice quality (BER-related), DMR, NXDN and P25 are about 1-3 dB better at rejecting interference than legacy wideband analog signals are (See TSB-88.1, Annex A). Its 6-8 dB better than narrowband analog. This is the same data the Part 90 frequency coordinators often refer to when licensing those systems.

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