gman1971

I think you may be unfairly characterizing the previous comment. I believe @WRAF213 was quoting the FCC’s own comments as a way of shining light on what might and might not be views and proposals the FCC would be open to entertaining. He did not claim to support or reject those views. 
My own personal view is that this discussion has pretty much served its purpose and it is now time to let it go before we reach the point of Godwin’s law: https://en.m.wikipedia.org/wiki/Godwin%27s_law

I would avoid that thing.  For ~200 dollars you can find a great deal on an XPR4550 Motorola Mobile that will draw rings around that.
 
G.

I would avoid that thing.  For ~200 dollars you can find a great deal on an XPR4550 Motorola Mobile that will draw rings around that.
 
G.

Unfortunately for the old stuff, Vocoder tech does indeed make a huge difference.... enough difference to make DMR sound better at even (arguably) half the bitrate. So it is not about the theoretical max bitrate being transmitted, its about how much those bits are actually encoding useful information, and a better compression algorithm will provide, like MP3, better audio quality at lower bitrates. I like to compare Vocoders to the Fraunhoffer MPEG Layer-3 audio (MP3) which can store audio at 1/10 the bitrate of an uncompressed PCM 16-bit WAV file and deliver near identical quality to that. Sure, an MP3 is still not as good as a 16-bit PCM uncompressed, which in theory is not as good as a true analog LP vinyl 33 RPM, but it takes 1/10th (at 128 kbps rate) the space of a PCM to send nearly identical information to the analog LP signal, and because the brain knows how to put it back together (ECC is in your brain, filling all the missing FFT analysis gaps, etc) you get a pretty much near perfect song. The MP3 codec was far superior to pretty much all of the pre-MP3 era audio codecs that preceded it. and the bitrates needed for an Mp3 to sound great were almost unheard of at the time (1:10 compression ratio in the early 90s was huge, when most consumer hard drives were still measured in megabytes) The same principle pretty much applies to newer Vocoders. Hence why I say, P25 Phase I its obsolete. Much like DMR will be made obsolete once a new Vocoder tech, or something new comes along and renders it obsolete (like Tier I DMR). GSM is obsolete not because of the more sophisticated radio modulations, but because the increased processing power than didn't exist at the sizes of today three decades ago to make such advanced modulations feasible. Newer modulations ranging from OFDM, WCDMA, LTE, QAM....  cell phones can do gigabits per second on just RF... compared to a 9600 baud FM radio the difference is measured in orders of magnitude, that is just ridiculous. So, to sum this long winded paragraph. Its about useful information density, not the bitrate, more bits doesn't mean a better useful information density. Newer Vocoders offer that, older vocoders don't.
 
As for Dual Capacity Diret Mode, or DCDM, it requires no infrastructure to work at all. Please understand DMR terminology (not just read it from Wikipedia) before emitting such statements, DCDM is a simplex Tier II DMR feature and pretty much any DMR Tier II compatible radio I've tried can do it. Even my 44 dollar CCR Baofeng BF-1801 DMR (a low grade GD77 clone) radios can do DCDM, and have two conversations on a simplex frequency. Can't do that with P25 Phase I, nor analog. Again, DCDM is simplex ONLY.
 
Then you can also go with a Tier I DMR on simplex if you want to run legacy stuff, operating the thing on full single carrier, which is obsolete too b/c you pretty much throw away all the benefits that a Tier II TDMA system has to offer.
 
In a Tier II DMR environment you're not limited to having to use a repeater, you can choose what kind of infrastructure use: you can go with a simplex double slot approach, simplex DCDM, or even simplex Tier I continuous single carrier. And then if you need it, you can chose the repeater double slot option too. You have infrastructure options, which you simply don't have on legacy obsolete stuff. Sure, for ham, P25 Phasie I is certainly fine, to talk about that SWR increase of the newest patch cable on the shack, that doesn't matter, but for a commercial customer, having these options, it makes the difference. (also for a family too) ETSI TS 102 361-x (DMR) was designed pretty much from the ground up to replace FM analog. 
 
Timing slots are for the radios talking at any given moment, there is no need to create an universal timing for the entire country. At any given site, its either the radios themselves (double slot simplex, or dcdm simplex) or a repeater infrastructure that takes care of the timing, and when interconnecting different sites, either using IP Site connect, or any kind of MMDVM, b/c these convert CAI to IP, those packets get sent over the wire to be rebroadcast somewhere else, so how its timed or modulated back to CAI at destination is up to whatever is being done there. Hence why MMDVM can do all this multi mode "ham stuff", you get the IP packet, retrieve the digital voice information and pack it up as P25, NXDN, Fusion... etc.
 
Also, timing on a DCDM simplex setup (b/c there is no DCDM on repeaters since repeaters operate on 2 timeslots), DMR Tier II radios on DCDM simplex will select a timing leader automatically, and I can see that they will chatter once in a while for a fraction of a second to figure out the timing between all of them, so when you press the PTT, all the radios are already synced up and communication happens.
 
In regard to DMR radio mixed mode, my Alinco DJ-MD5 does DCDM simplex with mixed mode analog+digital on the same channel, and will transmit back on whatever modulation the last received transmission was on just fine: It can listen and demodulate correctly DMR or analog depending on the signal that is being received. There is no "interoperability" with FM problem there, but at the same time I have all the DMR Tier II options that a legacy system like P25 Phase I simply lacks.
 
I still don't understand why range, or operating near threshold is relevant to this discussion? Nobody has argued that having better audio to threshold is bad. DMR has that too.... but FM wideband will still reach further. In addition, RF range can be extended using the right infrastructure, better radios, or both. 
 
As for hearing kids on GMRS: here is what happens. First off, I don't hear them breaking the squelch, ever, I never said that. when I hear them is when key my BF-888S running @ 1 watt power, which opens the squelch on all the radios used in the intercom, but if at the same time I am keying my intercom, a 5W portable starts talking, I can hear both radios on the channel. That is the issue I've experienced, which has nothing to do with signaling. Now, when testing DMR all we noticed was a slightly lower audio quality. 
 
 
G.
 
 

Going from 1 watt to 4-5 watts makes a fairly substantial difference (about 10dB more quieting; I'll test it later) when 1 watt is barely understandable, because the signal gets about 6-8dB stronger. Going from 25 to 40 watts is only a 2dB increase, the same as going from 1 watt to 1.6 watts. There are times when that 2dB advantage makes a difference, but it's so rare that it's not really worth it. FM sees a pretty strong rate of SNR improvement with carrier strength increase when it's close to or just above demodulation threshold, but once the signal reaches a good level of quieting there's almost no improvement that can be made using higher transmitter power.
 
[edit] Here's actual, on-air performance between low and high power near threshold.

FB2 is Single User Repeater
FB4 is Multiple User, "Community Repeater", Each user group (Ex: Bob's heating and cooling) is licensed for the repeater pair and their mobiles/portables.
FB6 is Multiple User, Common Carrier, Only the system (Repeater) is licensed, users are licensed as part of the system when they become users. 
FB7 Same as FB6 but non-profit
FB8 is a trunking repeater (centralized)

We now have four-letter words for people like that. 

Maybe this was my nickname when I first cobbled together two Jobcomm portables with duct tape to make a repeater without using those pesky and expensive filter thingy's back in the 80's....

Radioguy7268  is correct.  FB2 would also be fine for a private system.  However, the idle chit-chat that is common on GMRS is not actually permitted on the business/industrial service.   But in reality, it would never be challenged anyway as nobody really cares (including the Commission).     

Agree on the costs.  But if you need spectrum in a metro area, 6.25 kHz channels that may be the only thing available.   So you just eat the antenna, backup power system and additional rack space and site lease costs.   Ouch. 
 
TETRA - I forgot to mention this!   As GMRS uses 25 kHz wideband channels, that could support TETRA (I think it requires 21k bandwidth, so you would have to convince the FCC to go beyond the 20K GMRS limit; its already been done in Part 90).  Four TDMA slots would be more flexible than DMR's two and would further reduce message collisions among different groups. The handheld equipment is also quite nice, but still expensive.   
 
Since we have 25 kHz channels, it may be lower cost (considering both the repeater and user equipment) to simply split a GMRS channel in half and place two DMR transmitters there.
 
Normal Channel Center: 462.650
New Lower Channel Center: 462.650 MHz - 0.00625 MHz = 462.64375 MHz
New Upper Channel Center: 462.650 + 0.00625 = 462.65625 MHz
 
I just confirmed that the Motorola SLR5700 DMR repeater can be programmed for these channel centers.  Not sure about the CCRs.  
 
This now provides four repeater timeslots or channels in the place of one wideband analog channel.   Hmmm.....  
 
Greg 

The NXDN 6.25 is, IMO, nothing but a gimmick. For the non-tech person it looks like a panacea. And at first glance, its pretty obvious that you want to do FDMA and not TDMA, but once you start calculating budgets and figuring out what you need, you quickly realize that double the equipment per frequency is in order, with even tighter filtering, so twice or triple the cost of a TDMA solution.
 
IMO, again, IMO, for a less complex  2-way radio system (vs a cellphone system), I think a TDMA solution makes a much better use of the spectrum (like GSM did). And, again, personally, if I could afford to run TETRA I really would, I really like the TETRA b/c it has 4 timeslots vs just 2 slot of DMR. A TETRA implementation on GMRS would actually make the use of repeaters great, b/c now 4 guys can be talking simultaneously without messing with each other's talks. You can now use a public repeater to selectively call IDs (groups, individuals), rather than keying the repeater (and all that are linked to it) at 3:25 AM in the morning and waking everyone up to hear "WXZX1245, hey honey, I am going home." And lets not forget that, effectively, with a DMR/TETRA GMRS solution in place, most folks would have little need to build their own repeater for a less public (not encrypted) channel. Making good repeaters (like the Madison 700) now a viable option to have a group call with just your family so it doesn't open the squelch for a guy sitting in Indiana, who probably isn't very interested in hearing when you're going home. Maybe he is, but if so, he can run a nice thing called "promiscuous mode" so you can hear all traffic in the linked repeater network, but then, that is HIS choice. For a public GMRS DMR I would also filter ANY and ALL encrypted calls. Don't run encrypted crap, please, thank you.
 
One possible way to do this on DMR would be: Assuming a hierarchy of Repeater -> Call Sign -> Family. Lets begin by assigning a repeater Group Call ID for every repeater, this Repeater Group Call ID will be issued to all the radios that connect to it via direct RF, so for example, for the Madison 700, the Group Call ID could be, say, ID 1000, and consequently all the registered radios that are in the Madison area will be listening to the 1000 Group Call. Then, when a new licensee signs up on the repeater, they get assigned two DMR IDs, first one is a Group Call ID, linked to your callsign, which will be then subsequently used by anyone under your callsign (ie. family) and a Private ID just for any new radio you get. So, now, when the wife gets a radio, all you get is another private DMR ID for that radio, and set the radio to listen to both the Group Call ID under your callsign and the Group Call for the repeater. So, now that GMRS repeater has become a pretty viable family comm service (which is what GMRS was meant to be) And then, b/c DMR allows to have 2 people talking at the same time (even more I think with the higher end Moto stuff)  so again, digital makes so much more sense IMO. So you can effectively utilize repeaters like the Madison 700 area to do what GMRS was really meant for, and without bugging everyone and their mother (and especially when the repeater is linked all the way to Indiana from Wisconsin... holy cow, my simple radio call "WQXXXX, hey honey, I am going home" was heard all the way down to Indiana... that doesn't sound very appealing to a lot of people, hence there will be much less "repeater proliferation")
That is just for basic GMRS family comms. But then you can create Group Calls for different things, like hobbies, say, there is a buch of GMRS guys who like RC planes and another who really likes "basket weaving", or guns, or Corvettes? No problem, create several group calls, ID 40001, 40002... so on so forth, and if you like RC planes, you just add that group ID to your personal radio, or if you like basket weaving you listen to that ID, so the guys who hate "basket weaving" don't have to listen to the "basket weavers" yap all day long about how awesome it is,etc. Same goes for RC planes, or whatever it is that floats your boat.
 
Again, this is just my opinion, I clearly understand that the current FCC regulations don't allow for any digital modulation at the time of this writing, so don't use digital, but then again, dreaming is for free.
 
G.

Agreed.  HT antennas use your body as a counterpoise.
 
I'll start a new thread about this so I don't completely derail this one.

I would like to add that it generally takes 2 s-units to hear an appreciable difference in signal strength. So as long as your 1 watt is enough to be heard without dropouts, it will take 16 watts to make any real difference.
If your signal is readable at a 1 watt "low" setting, there is no reason to switch to "high" power as that will only drain your battery faster. The 4 or 5 watt setting only has any relevance in a case where the low setting is strong enough to be heard, but is dropping out.
 
In my experience, there is zero reason to seek out the 40-50 watt "H" version of a particular mobile radio. It really won't do anything noticeably better than the standard 25 watt radio. But it will use more battery power, get hot faster, and find any substandard connections in your wiring faster than the lower power radio. It will also subject you and any bystanders to more RF exposure. And it is more likely to negatively affect the computer and other electronics in your car or home. That's much more prevalent than you might think, too. The manufacturer of your vehicle or home computer couldn't care less about your 2-way radio activities.

Absolutely, finding higher ground should be the first step towards improving a setup. Running more power only matters on fixed setups where the antenna is already as good as it can get, or on mobile operation where there is no 'finding a good spot'. Even then, there's not a huge difference between 15 and 40 watts.
 
Here's my first piece of advice for new users (and I have a bunch, fair warning): use scan mode on a radio that will tell you the active CTCSS tone or DCS code if you're looking for repeaters to use. RTL-SDR is also a good tool, and makes the entire 462 MHz band visible with good sensitivity and excellent selectivity.
 
Especially on fixed setups, grounding is important. Noise will get picked up along the coax and travel up to the antenna, where it enters the receiver. The effect is very apparent on SDRs, where the noise floor is directly visible. When grounding a setup, check for ground loops with a multimeter.
 
Learn to recognize the busy-channel indicator on your radio. When the radio detects any activity on the channel, regardless of correct CTCSS/DCS, it'll turn on the busy-channel indicator. It'll help you to know if you have the correct CTCSS/DCS for a particular system. Some repeaters use multiple CTCSS/DCS, so this indicator can be useful on those repeaters to make sure you aren't interfering with a different conversation. On Baofeng's radios, this is the green LED on top of the radio. On Motorola's commercial radios, this is a blinking red or green LED near the antenna; on their FRS/GMRS radios, this is the red LED above the display.
 
Some repeaters transmit CTCSS/DCS back to you, but only while someone is transmitting to it. If you're hitting the repeater but can't hear it come back to you once you finish transmitting, this could be a possible cause. Use the monitor feature on your radio or check the busy-channel indicator to check for the repeater's tail.
 
Don't be afraid to try simplex. If you hear a callsign with variable signal strength, they're probably not going through a repeater. It's rare to find contacts that way, but that's largely because hardly anyone calls for contacts on simplex. 462.5625 (channel 1), transmit and receive CSQ; and 462.6750 (channel 20), transmit CTCSS 141.3 and receive CSQ are good places to try calling CQ.
 
People who use MDC-1200 on their radios don't actually have to hear the data bursts, the radio can detect the burst and mute it. It gets annoying so most people with MDC-1200 radios have their radios like that.
 
This forum sure does love their Kenwood TK-880s and Motorola M1225s. They're great radios, but terrible general-purpose radios. Virtually all commercial radios can only be programmed by computer software, so you have to know ahead of time what you're going to talk to. Speaking of commercial radios, used Motorola HT1000 radios are incredibly durable and inexpensive. They use the same programming
 
Don't waste your money on the BTech GMRS mobiles, the quality control is practically absent. The GMRS-V1 is apparently alright and Part 95 accepted. Use CHIRP for programming; it will save a lot of time and headaches, while allowing for named channels.
 
When buying a used radio online, make sure the frequency range actually includes 462-468 MHz. For handheld radios, make sure that you are getting (or already have) a charger and antenna. The battery is probably shot, so include a replacement in your budgeting. I like to have at least one spare battery, so I can continue using the radio while a battery is charging. Don't transmit on a handheld radio while it's charging.
 
Counterfeit antennas are a thing, especially with Nagoya. Buy from trusted sources, or find a friend with an antenna analyzer or VNA who'd be willing to show you how to see if an antenna is good or trash. Be willing to learn how to use test equipment, or at least be aware of what that test equipment is testing. It'll help greatly in the future when you are faced with new problems.
 
GMRS isn't ham radio, but it's often used pretty similarly to 70cm. Ham radio clubs are still a useful resource where you can make lots of friends with lots of knowledge. If you don't have a ham license, they'll pressure you to get one. A Technician-class license is easy to get, costs much less than your GMRS license, and you may even be able to use the same antenna for 70cm. Different clubs have different focuses, so don't get discouraged if you don't feel a particular club is right for you. Depending on the area, hams may not like GMRS for one reason or another; but recognize the common interest in establishing reliable communications between licensed operators.
 
There's a 30 MHz gap between 70cm and GMRS, so most 70cm antennas with appreciable gain don't work on GMRS (and remember you're usually transmitting at 467 MHz, not 462 MHz). Check your antenna's documentation to see how much bandwidth you have. Most handheld antennas are broadband enough, and most commercial-band antennas actually work better on GMRS.
 
Don't put up a repeater until you know exactly what you're doing. There's enough deaf GMRS repeaters out there. Don't take on the task alone, either. The more support you have, the better (and, for you, cheaper) the repeater can be. Even a low hilltop provides significantly more coverage than a rooftop repeater. Sites cost money, but can cost a heck of a lot less if you get to know some repeater folk and can make a good sales pitch. Don't use LMR-400 for repeaters.
 
Getting above the roofline makes a big difference in suburban areas, particularly when trying to work hilltop sites. For more rural areas, try to get above the treeline if possible. If you're the only one-story house in a block of two-story houses, ouch.
 
Be it ham radio or GMRS, remember that the radio hobby is about communication. This includes, but is not limited to: rag chewing, technical talk, emergency communication, repeater building, proselytizing the wonders of properly configured radios, and being willing to help the confused. A lot of people out there try to assert their dominance over a channel and run around with a better-than-thou mentality, and over the course of your license you'll find at least one of them. They aren't out to improve either service or what each service stands for, so stay away from them. Don't let them change your perception of the radio hobby, either.
 
If you hear confused FRS users on channel 1 that can't get their radios to talk to each other, offer to help. Transmit CTCSS 67.0 and receive CSQ. They'll probably need help configuring CTCSS on their radios. Ask for the model number and look up the manual on Google. Stuff like this happens more often than I'd like to admit, and half the time those people spent a lot of money on those radios. Be a good citizen.
 
Some repeaters will beacon out their callsign. That doesn't mean there's anyone using it. Repeaters aren't supposed to do that, but not everyone has a good repeater controller. It's almost universally agreed upon that such repeater behavior is super annoying.
 
Not all repeaters identify, and that can make it a pain in the rear to figure out who owns the repeater. It's usually private repeaters that don't identify, and some legally don't even have to. It's another fact of life that makes frequency coordination difficult for repeater owners.
 
The FRS channels, especially 1-14, are flooded with business users. They're allowed to be there, and aren't looking for conversation. Let them be. They're close enough together (a few hundred feet, typically) that they won't even notice you're on the same frequency as long as you're on a different CTCSS/DCS code.
 
Not everyone is following the rules. Report egregious violators to the FCC, but don't expect enforcement action. Report criminal activity (eg. terroristic threats, use of radios in a crime) to law enforcement, not the FCC. If you happen to know who the perps are, tell the FCC as well. You probably won't encounter any such activity.
 
If you start getting involved in the commercial radio users crowd, be it on 70cm or GMRS, you'll see a lot of brand loyalty. I'm a Motorola guy, since those are the first commercial radios I got involved with and those radios meet all of my needs. We have a lot of Kenwood folk on here, and boy do they love their TK-880s. Both make rock-solid commercial radios. There's other brands out there, too. Stay away from cheap Chinese radios, those are markedly not rock-solid radios and may not have any type-acceptance whatsoever. It's generally accepted that radios with commercial (Part 90) type acceptance are fine for GMRS (Part 97E) operation, since Part 90 requirements are more stringent in terms of RF performance. While the FCC is yet to make an official exemption, they allude to it frequently in the 2017 rule change discussion.
 
Directional antennas (mostly Yagis or log-periodic antennas at these fequencies) are terrible general purpose antennas, since you need to know the direction towards the stuff you want to talk to. Commercial omnidirectional antennas covering 460-470 MHz at a minimum make the best general-purpose antennas. Browning's BR6157 is a good starter antenna, with some gain and a wide bandwidth. If you spend more than $60 on one before any sales tax, you've overspent.
 
Use FakeSpot when shopping for radios or accessories on Amazon. Don't get ripped off by fake reviews.
 
Monitor channel 1 (again, transmit CTCSS 67.0 and receive CSQ) during disasters. You may save someone's life. Prioritize your safety highest; you're still a victim.
 
Don't be a dillweed on the air that hides from consequences behind a microphone; respect is reciprocal. Not everyone you'll meet understands this.
 
When you got your GMRS license, your whole family just became GMRS licensees as well. Come up with a separate simplex channel for them and them only. It's useful when outdoors, communication between vehicles on road trips, or during disasters. Having a nationwide license to operate a radio without frequency coordination, and with unlicensed operators on FRS, is a beautiful luxury we have on GMRS that you will get nowhere else. Make sure to test your channels ahead of time, and check them regularly if you don't use them often.
 
I mentioned it earlier, but I'll elaborate on it: RTL-SDR is an excellent tool for GMRS. All of the output channels are visible with a spectrum analyzer-type visualization. Interference becomes easy to spot and identify. CTCSS and DCS decoding is straightforward and nearly instant, and works with hardly any signal strength at all. Signal strength readings can be calibrated against an absolute scale (dBm), which allows for comparison between antennas and locations. A fancy setup of them, Kerberos SDR, can do direction finding with real-time map plotting, but requires some technical knowledge. SDR is fairly recent, and there's plenty of user groups online (like Reddit's r/RTLSDR). When shopping for RTL-SDR, don't spend more than $30 for a bare unit, and don't buy anything that doesn't have a 1.0ppm TCXO or better. If the item description doesn't say TCXO, it doesn't have one.  RTL-SDR Blog v3 is a good unit, and the Nooelec NESDR SMArTee performs the same. Throw the RTL-SDR Blog 20dB LNA on there as well, life will be much better. Use a USB 2.0 extension cord with SDRs.
 
Talking on a handheld radio while driving a vehicle is illegal in California under the cell phone laws. Mobiles, with a simple PTT-only hand mic, are fine.
 
Don't get a 16 or 48 channel radio as your first real commercial or commercial-grade radio. Go for something with at least 128 channels and a screen. Get the programming software and cable before you get the radio so you aren't stuck with a paperweight. Don't give money to HamFiles.
 
If you have a lot of long conversations but all you have is your handheld radio, get a mobile radio and a power supply. Use a proper antenna (as discussed earlier) and some low-loss coax (RG-8, LMR-240, or better). PL-259/SO-239, also called the UHF connector, is a terrible connector at UHF. Avoid it wherever possible. Use TNC or N for permanent or semi-permanent connections, and BNC for connections you switch out a lot. Keep your connectors clean and seal any outdoor terminations. Assume each adapter adds 0.5-1dB of loss, so use as few adapters as possible. Get your coax terminated in whatever connector your antenna has; don't leave the adapter outdoors. Mastic tape gums up over time and future you will hate present you. If you use cheap non-outdoors coax like I did, it can get water ingress. SWR will still show a rather normal reading, but the wet insulator will suck up all your RF (easily 99% of it).
 
Good coax is thicker than you think. Take that into consideration.
 
Folk at your local ham radio club, or GMRS club if you live in an area with one, have done enough fixed radio installations to be able to help you with yours. Don't go out alone and do it, but take some notes so you can eventually help others. Honestly, they're not that hard.
 
If you're in a place that gets thunderstorms more than a few times a year, lightning protection is a real concern. Nothing will stop a direct strike, so unplug your equipment during such inclement weather. That's another reason to keep portable radios around.
 
Repeaters almost always use hardline instead of flexible coax. Hardline is expensive and requires special tools. Good feedline is critical on repeaters because you usually have a 40-watt transmitter on the same antennas as a sensitive receiver. Slight non-linear effects, even a rusty fencepost nearby, can cause issues with receiver performance.
 
If you have an opportunity to visit a hilltop repeater site (an opportunity you may get if you're involved with repeater groups), take it. The first trip to one is an experience, and you'll get to see a variety of real-world installations. Hilltop sites are surprisingly dirty; nobody's up there keeping the floors clean. Some sites are cleaner than others. It's often a long drive and fair distance from civilization, so bring a lunch and go to the bathroom before the trip. Some sites require four-wheel drive and an experienced driver to get to. Buy their dinner.
 
Flat areas can get significant coverage from a low-level repeater. Rooftop repeaters actually have decent performance in those environments.
 
Even on rooftop antennas, your simplex range to a five-watt mobile/portable can be as short as two miles. GMRS is heavily influenced by line-of-sight propagation. Building penetration is better than MURS or 2-meters. 

I have seen a few posts talking about getting more distance out of UHF gear, such as the GMRS equipment we use. It looks like the common theme is, many immediately want to go for more power, assuming they can brute-force their way through issues. I am hoping myself and some of the other people who have some training and practical experience can use this thread to help new users understand how to make life better without more power.
 
I want to start with handheld transceivers. HT antennas use your body as a counterpoise. Depending on how you are dressed, how tall you are, how you are holding the radio, the radio position, the distance of the radio from your body, what direction you are facing, all impact performance. Even how much fat, salt and water your body is retaining at the moment impacts how an HT antenna works, because those things vary the conductivity of the human body. In all seriousness, forget about more power... or even more range from a typical HT.
 
If you want more range out of your HT, your best bet is to find higher ground, figure out where the best place to stand is, and what general direction to be facing when compared to the receiving station provides the best communications path.
 
 
Mobile antennas are often several wavelengths+ in overall height and the body of the vehicle is typically a much better reflective counterpoise. There is a lot that can be done in the mobile and base antenna world that can help, but for now, lets continue to focus on why 'more power' likely isn't the right answer.
 
 
 
There is a standard in radio communications about intelligibility of radio communications. It is called the 5/9 scale. 0 to 5 for voice clarity and 0 to 9+ for signal strength in s-units. It is said that while a 2/1 signal provides partially usable comms, the lowest "reliable" communications happens at a 3/2 (or 32) and the best is a 5/9+ (often called 599, 59+20, 59+40).
 
With that in mind, you have to quadruple your power to impact a receiver 1 s-unit. So, if the other party is receiving a signal at 1/2 s-unit while you are using 4 watts, you need 16 watts to go to 1 s-unit. You then need to jump to 64 watts for 2 s-units. Finally a third jump in power of 256 watts to get to 3 s-units and possibly getting a reliable communications signal (a 2/3 or 3/3). Depending on the modulation of the carrier signal and bandwidth, you may need to jump to 4 s-units, requiring well over 1,000 watts.
 
Now, lets say the same receive condition exists, but now you are already using 20 watts for that 1/2 s-unit. Now your power jumps are 80 watts, 320 watts, 1,280 watts for 3 s-units and possibly needing 5,120 watts for 4 s-units. Well, the first bump you made already seriously violates power restrictions in GMRS.
 
AND, this is under hypothetical perfect conditions, assuming nothing else changed in the environment. Which almost never exists.
 
Chasing better performance by boosting power typically doesn't give you any truly desirable results. The top 3 items that will help improve comms in almost every band is elevation, elevation, and elevation. From there its antenna tuning (and beams) filters to reduce interference and lowering the noise floor, as some examples.
 
 
 
So, for our technically skill folks... Would anyone like to contribute some general advice for new users to benefit from?
 
General advice on what to do or not to do?

I just don't see the ban going on for much longer. I think we as a community need to step up and make a convincing case, on the record with the FCC. When they denied the requests to permit digital voice, they specifically mentioned that there was insufficient discussion about it in the record, and thus they could not make a ruling. Once a Petition for Rulemaking is filed with a very narrow set of requests (not the kitchen sink arguments that were flying around last time -- mostly due to so so many proposed changes by the FCC, we had to defend all of them), key GMRS groups and radio manufacturers will have a chance to discuss it officially on the record and the FCC can make the determination.
 
Even still, the main issue I see with allowed digital voice is that no Part 95 equipment (to my knowledge) is even capable of being programmed to enable it. Maybe one or two models exist that carry dual Part 90 and 95 certification. Assuming the FCC even decided to lift the restriction on digital voice, one of three things will need to happen:
 
The manufacturers will need to begin adding digital to their lineup of radios. This is not impossible, as some low-cost dPMR radios exist for Europe, but I don't see it as something they want to jump at right now. I think the tide will turn within the next 5-10 years, but that's quite far off.
  The FCC would need to permit GMRS licensees to use Part 90 equipment. We've been down this road before, and they pretty much completely shut down the argument. Their position seems to be that the manufacturers just need to submit their equipment for type certification and there would be no issue.
  The manufacturers will need to begin certifying their equipment for Part 95 as well. For whatever reason, the manufacturers seldom cross-certify for Part 95. We're only just now getting some of the Chinese radios to have Part 95 certification (much to the chagrin of some of us), but getting Motorola, Kenwood, Icom, etc to follow suit has not been going very well. GMRS and FRS were lumped together so GMRS radios ended up being seen as bubble pack radios to sell at Walmart, not for more robust communications. Hopefully now that the combo radios are no longer able to be marketed, that means GMRS will finally get some non-bubble pack love. Digital formats are finally working their way into cheaper radios (mostly DMR at this point), so hopefully the market for digital personal communications will continue to grow and the manufacturers will get serious about meeting the demand. I think this lack of motivation will be a driving factor in the FCC not permitting digital formats in the near future. I also think the bubble pack manufacturers will sit back and moan that digital doesn't do anything special and they don't want to hear complaints of interference. 
 
It will need to be a concerted effort to get this done, but I think the case can certainly be made. Everybody needs to be on the same page and the argument eventually has to be had on the record, not just online in forums. 

We are not saying the FCC should require digital - just give people the option to use it if they want.          
 
Digital does not cause more interference unless you can violate the laws of physics with it 

I don't think favoritism toward a particular standard would be in the best interest of the public, and likely wouldn't be specified by the FCC. What they are likely to do is specify a very limited set of emission designators which may or may not include the type of digital you're hoping to use (i.e. a TDMA format like DMR). So, if anyone has hopes of using DMR one day, they really need to make sure the FCC permits the associated emission type.
 
For example, here are some common formats and their emission designators. The last 3 digits are significant as they designate the modulation and type:
 
2-slot DMR (MotoTRBO) voice 7K60FXE
2-slot DMR (MotoTRBO) data 7K60FXD
 
P25 Phase I voice 8K10F1E
P25 Phase I voice 8K10F1D
 
P25 Phase II has several designators, of which 8K10F1W is one type
 
NXDN 6.25kHz (IDAS/NEXEDGE) voice 4K00F1E
NXDN 6.25kHz (IDAS/NEXEDGE) data 4K00F1D
NXDN 6.25kHz (IDAS/NEXEDGE) voice+data 4K00F1W
 
NXDN 12.5kHz (IDAS/NEXEDGE) voice 8K30F1E
NXDN 12.5kHz (IDAS/NEXEDGE) voice 8K30F1D
NXDN 12.5kHz (IDAS/NEXEDGE) voice+data 8K30F7W
 
We are most likely to see the voice emissions allowed but not sure about the data or combined voice+data modes. Note that DMR is actually FXE and not F1E, which means an oversight (intentional or otherwise) by the FCC could exclude DMR simply my omitting its emission type.
 
Now back to my opinion, I prefer DMR. Early on NXDN was a winner in my eyes, but once DMR became more openly supported and the Ham community embraced it, it has become the clear winner. Since we cannot benefit from 6.25 kHz channels on GMRS anytime soon, narrowband NXDN doesn't do anything for us except minimize adjacent channel interference, which typically isn't a big problem on GMRS to begin with. We just don't want to be locked into a particular standard and then when something new and improved comes out, we're locked in by the Part 95 rules. If it meets the emission designators, it would be open to use.
 
TDMA systems like DMR, however, allow us to use a 12.5 kHz channel (really a 25 kHz channel, but we're occupying 12.5 kHz in this case) with 2 time slots, or virtual channels. This doubles our efficiency on a given channel, even if GMRS isn't so busy to really need it right now.
 
It would be good for putting up one repeater and having 2 distinct usages like a private slot for the individual/family putting up the system, and a slot open for the public to use. The two groups can coexist and transmit simultaneously without affecting each other.

I disagree, on FM this isn't an issue. If the 2 stations are far enough away that they do not interfere on analog, they would similarly not interfere on digital. It's only a problem when the two systems are close enough that analog interference would occur, then the digital signal would cause nearly identical interference. The problem is when a digital transmitter is transmitting all the time (like with trunking control channels), because the analog users would hear constant noise on the same channel (no matter how faint), rather than intermittent transmissions on a normal voice channel.
 
Remember, a digital radio transmission is NOT a digital waveform, and therefore is no more harsh on FM than an analog transmission. The wave is still a sine wave, but the modulation being applied to it results in one of a few levels of frequency shift, since it's FM (commonly 4-level FSK is used). That means that the carrier (present whether on analog or digital) is going to shift either up one of 2 frequencies or down one of two frequencies to represent 2 bits of data (00, 01, 11, 10) rather than only one (0 or 1). What you're hearing on an analog receiver is actually the rhythmic fluctuations of the modulation, shifting up and down as the bits are transmitted. 
 
By contrast, analog is rather chaotically modulated by the actual audio being transmitted (a much messier wave, but conveniently one that you can understand as a sound wave/speech/tone/etc).
 
At the end of the day, it doesn't matter what is modulating the carrier wave on FM. A digital signal doesn't actually go any further than an analog signal, it's just that a digital receiver can more easily distinguish, for example, one of 4 frequency shifts on a faint carrier than it could with 8 kHz of audio (including a CTCSS tone) to open up squelch. Hence, most digital radios have better sensitivity on digital (at the expense of a higher error rate in decoding the bits [known as BER - Bit Error Rate]).

What software are you using?  If it is CHIRP, go to the link below. I posted a bit in there that should help.
 
https://forums.mygmrs.com/topic/1639-using-chirp-to-program-gmrs-repeater-into-handheld/
 
Do yourself a favor.  Unless the radio isn't critical and is being used in a rough/dirty environment that will likely break radios due to contaminant exposure, don't by any of the following brands...
 
TYT
QYT
BTech
BaoFeng
LEIXEN
Retevis
Zastone
EasyTalk (EZTalk)
Rivins
HYS
TALKCOOP
Radioddity
SAMCOMM
BACKCOUNTRY
ANSOKO
TIDRADIO
BOCOTRAN
ANYSECU
Stryker
TWAYRDIO
Ailunce
 
 
There are more to stay away from... but I think you get were I am going with this.  And if you are tight on cash... that is an even better reason to stay away from them.  CCR's are cheap for a reason.  And its not because they are reliable or good performers.  Don't waste your money.

No, the specs aren't guaranteed anywhere. We'd see at least some kind of transmitter certification in that case (Radioddity says it has an FCC ID of POD-ANG7, but that gies to a completely different radio). These usually end up as business radios in other parts of the world where FCC type acceptance isn't needed (look at all the DTMF signaling features), so they're usually designed for optimim performance in the 440-460 MHz range. 460 MHz is roughly in the middle of its bandsplit too, and 470 MHz is not far off compared to its transmitter's range. I'd expect transmit quality to start to deviate from spec below 425 MHz or above 480 MHz, and only in transmit power level. The majority of the transmitter circuitry and virtually all of the receiver circuitry is on a single IC whose performance is guaranteed (to a fairly low bar) across that range. Once RF comes out of that chip, it just needs to be filtered and amplified. One of those tasks is more expensive than the other, so that critical step is often not to FCC spec on these classes of radios. Filtering is rarely omitted entirely, but also rarely sufficient to exceed the 50-dB-under-carrier spec with enough margin to account for production variability. The cross-band repeat will also intermodulate with the third harmonic of the VHF side, which would guarantee it'd fail FCC testing; but that feature would not even be allowed on a type-accepted radio in the first place.

Yep, Marc is right. Unfortunately my experience with more power is even bleaker than Marc's experience, b/c for me, going from 5 to 50 on GMRS netted zero additional miles, yep, you heard that right: nada, zip, zero.... which pretty much proves what Marc's post stated: "If your in a bad spot, it won't matter how much power you're running."
 
May I ask what is it that you're trying to do? A Base to Mobile? Base to Portable? Mobile to Portable? Portable to Portable?
 
Also, for whatever is worth, as a former Baofeng addict, always running on Baofeng budgets, etc, always mesmerized by their fancy color screens and pretty LEDs, etc; I had to get out of that trend of thought and buy higher quality (with no color screens, nor fancy and useless bells and whistles) commercial grade Vertex Standard radios, which draw rings around the BTech stuff where it matters: in the RF performance department... with tighter receivers (key factor) that won't desense in high RF environments, which nowadays is pretty much anywhere near a city larger than 500 souls population....
 
G.

Yep, Marc is right. Unfortunately my experience with more power is even bleaker than Marc's experience, b/c for me, going from 5 to 50 on GMRS netted zero additional miles, yep, you heard that right: nada, zip, zero.... which pretty much proves what Marc's post stated: "If your in a bad spot, it won't matter how much power you're running."
 
May I ask what is it that you're trying to do? A Base to Mobile? Base to Portable? Mobile to Portable? Portable to Portable?
 
Also, for whatever is worth, as a former Baofeng addict, always running on Baofeng budgets, etc, always mesmerized by their fancy color screens and pretty LEDs, etc; I had to get out of that trend of thought and buy higher quality (with no color screens, nor fancy and useless bells and whistles) commercial grade Vertex Standard radios, which draw rings around the BTech stuff where it matters: in the RF performance department... with tighter receivers (key factor) that won't desense in high RF environments, which nowadays is pretty much anywhere near a city larger than 500 souls population....
 
G.

Agreed.  On field testing, mobile to mobile, bumping the power from 5 watts to 50 watts only netted an additional 1/4 mile.  That's it. 
 
The only time I can see any benefit to boosting power is in a flat-out life or death emergency and you are trying to increase the odds of someone/anyone hearing you.  And even then, if your in a bad spot, it wont matter how much power you're running.

You noted you want to keep your power as low as possible.   Just curious what the reason is.  
 
I agree that the difference between 10 and 15 watts is negligible (+1.75 dB).  Most users (including me) can barely notice a doubling of transmit power (5W to 10W, or +3 dB), even if the user is noisy; they may start to notice a difference if you quadrupled your power (5W to 20W, or +6 dB increase).  I always try and improve things by +9-10 dB to make a noticeable difference.
 
While 9 dB can be attained going from 5W to 40W in one shot, you likely have a good reason for not going there.  So get this 9-10 dB from a combination of things - maybe increase power slightly and improve antenna gain slightly.    
 
Maybe go from 5W to 20W (+6 dB), and use a yagi that **has 3 dB greater gain** than your current antenna.  That gets you 9 dB total. 
 
Your cable loss is like -1.2 dB (cable plus connector losses).  You could halve this to -0.5 dB using better cable (e.g., LMR400 cable), but the cost is high for little gain, considering you are aiming for 9-10 dB overall.
 
If possible, change antenna height/position to eliminate close-in obstructions (buildings, trees).  This can give you 6-9 dB in one shot in some cases.
 
Finally - if the radio has a "Wideband/Narrowband" setting, make sure you operate "Wideband" or "Wide" if operating through the vast majority of repeaters.  This alone can gain you +3 dB of effective improvement, particularly if you are already weak.  
 
Also - if you have a SWR or watt meter, or know somebody who does, make sure the antenna system is performing.  Also - make sure you are not trying to use a UHF amateur radio antenna designed for 440-450 MHz, for 462/467 MHz.   Some amateur antennas work great on both, but most don't. 
 
Sorry for all the math.  We use dB because the values can be easily added and subtracted; easy math for my simple and lazy mind.