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#11353 You just got your GMRS license, now you want your own repeater?

Posted by Corey on 18 March 2019 - 10:29 AM

Why does every new license holder want to setup a repeater? I would like to shed a little light on some of the important things to consider if you recently got your GMRS license and now want your own repeater.

 

First thing to consider, are there any open well placed repeaters in your area that you are able to use? I can assure you most repeater owners want people to use there repeater. Owning several repeaters I can assure you all are welcome and encouraged to use my machines.

 

Do you have access to a location to host your repeater? If your answer is your garage roof you should reconsider. Your garage roof will give you about the same coverage as simplex. Unless you’re on top of a mountain and all your users are at the bottom you will never be happy with this setup.

 

GMRS is not as popular as one would like to think, unless your repeater covers 20 miles or more you may find you only have 1 or 2 users in the area. Unless you already have a group of friends together you may want to consider this before spending money on a decent well positioned site to install your repeater.

 

So you found a nice high site and the price is right, all you need to do is get the repeater installed, sounds simple right? Some thigs to consider first and foremost are the costs because they can add up quickly. Are you on a commercial tower that requires a license and bonded climber? If so this could be by far your largest expense depending on your area. I have spent $600 to $1200 on a climber; I have had quotes as high as $2500 depending on the amount of work and heights involved.  Keep in mind commercial sites require certified mounts, hard line cable, cable clamps, engineered grounding solutions and commercial grade antennas. No tower owner is going to let you install a comet antenna and 200’ of braided shield coax.

 

This brings me to my next point, the antenna. Because of the costs involved with climbers you will want to expend your budget on the antenna. Remember a $2000 repeater on a $200 antenna is going to work about as good as a $200 repeater.  Whereas a $200 repeater on a $2000 antenna is going to work like a $2000 repeater. On my first repeater I was gifted use of a 150’ tower, I installed a DB-420 on the top and 160’ of 7/8 hardline. Total cost of equipment for the antenna install was $2500, with the climbers labor coming in at an additional $800. This left me with enough to purchase an old Motorola R100 repeater running at 25W. To my surprise it had 30 miles of coverage, all due to the cash spent on the antenna and waiting for a decent spot.

 

Things happen, more so if you have an antenna 200’ in the air with a conductive cable connected to sensitive electronics. Antenna issues, feedline issues, repeater issues all cost money and I promise at some point you will have issues that need repair and require your money!

 

It is my opinion that the GMRS community does not need another 2 to 5 miles repeater as it just becomes background noise. What use is a public listed repeater if somebody in a mobile can’t use it 5 miles away while moving or the portable coverage is only a mile? If after reading this you are still going to build a repeater for your garage more power to you, just don’t expect 20 people to show up if it only reaches a mile.

 

As the owner of several GMRS and Commercial repeaters I can attest to the amount of money and effort go into my repeaters. I have only touched on the basics, if you add in any kind of testing services, duplexer tuning, addition of a combiner channel to an existing tower system, RF engineering, rent and insurance your costs can sky rocket. The best advice I can give any new licensee is to try and use the available systems in the area. Take the time to learn a little about what you’re doing and to assess the usability of the service before investing in a repeater for the sole reason of saying you own one.


  • JohnE, Logan5, quarterwave and 8 others like this


#12329 MyGMRS repeaters list needs updating?

Posted by WQEJ577 on 01 June 2019 - 11:21 PM

I've been working on a new map replacement which will hide old and offline repeaters by default, but still gives you the option of showing them all.

 

https://mygmrs.com/map-new/

 

I still have a lot of things to add to make it ready to replace the current map, but I wanted to share the progress now and get feedback from the community here. Some outstanding issues are:

  1. The label below each icon needs to be styled, so it stands out against a dark background. I'm having trouble getting this to work with the library I've chosen to use on this version of the map, but I'm sure I'll be able to find a way without scrapping anything.
     
  2. Clicking on the repeater icon should modify the URL to point to the repeater ID that is selected.
     
  3. Repeater details (the description field) aren't visible yet.
     
  4. Several repeaters do not have GPS coordinates and show up at 0, 0 which is off the coast of Africa. This is mainly a problem with the database that needs to be fixed, but the map should hide them since it's obviously wrong.

At least the performance of loading that many repeaters and toggling the switches on and off seems to be quite good. Let me know if it's slower for you than the current map.

 

I have big plans for a complete site redesign to make it more modern. I've headed down this path several times but got bogged down between work and my personal life, so I never got a complete redesign done. I've been making small changes here and there to support this big effort, so I'm hoping we can get a better site off the ground which will solve some of the pain points like the stale repeaters.


  • Corey, n4gix, berkinet and 6 others like this


#12168 GMRS-50X1 Features Review

Posted by marcspaz on 17 May 2019 - 10:56 PM

Hey folks!  I know I said I was going to wait a few days... possibly a week... before my GMRS-50X1 features review, but I spent hours using this radio today and I had a great time.  I figured I would just go ahead and get it out there.

 

For the features review, I am going to start with the Cons this time.  Since the quasi-tech review ended with the focus on the negatives, I would like to end this review with a positive vibe.  Please keep in mind, this is purely opinion based after using the radio.

 

There are tons of features... I am only going to cover what I believe would be the most common/popular to use among most people.

 

 

Cons -

1.) While talking simplex to a station that is closer than 2 miles, I had to use low power, NFM and turn the mic gain down to 1.  If not, the person I was talking to complained about audio clipping and audible popping sounds.  After 2 miles, I could turn the mic gain back up and use WB FM.

 

2.) The display is going to be both in the Pros and Cons section.  As some are aware, I daily drive a Jeep Wrangler.  For at least 50% of the year, my Jeep has no roof and no doors.  That fact brought out a big drawback for me.

 

The display has no means of adjusting the brightness.  Regardless of what I did, while the sun was out and the roof and doors were off, the display was 100% washed out.  I literally could not tell the radio was on by looking at the display.  At first, I put the soft top on, and the display was still heavily washed out, but was usable.  I had to put on my top and my doors with 20% light transmission tint on the windows, before the display was good to use.

 

Another drawback for the display is, there is a lot of very useful information in a tiny little spot.  It takes a bit of focus to look at the display and get a feel for exactly what is going on.  This is not good if you are driving and want to make a quick change.  I found that I had to pull over to be safe while making minor adjustments.

 

2.) They advertise that it has NOAA radio built-in, but it really doesn't.  The VFO covers a frequency spectrum that includes those frequencies.  Not a big deal, but it is up to you to manually tune to those channels and save them to memory. 

 

3.) You can't add new GMRS saved channels that are capable of transmitting.  On my iCom, I have multiple saved channels for channel 15, for example.  One with no DPL, one with tone coding and one with digital coding.  Depending on who I am with or the group I am talking with, I need to use different values.  With the BTech radio, I will have to manually change it every time.  I am assuming this is so they could get FCC type approval.

 

4.) You can't transmit in VFO mode, at all, not even on GMRS frequencies.  This was probably needed for FCC type approval.  Still a drag that you can't manually dial to a GMRS frequency and use it.

 

5.) There are a lot of unneeded features and unusable functions that are locked out.  Seems pointless to even have them because they will likely add a lot of confusion to new operators.  Examples are Remote Stun which remotely disables transmitting and Remote Kill remotely disables transmit and receive.  These are typically repeater management features that a typical GMRS mobile user just doesn't need. 

 

While the aforementioned features are present and function, there are a ton of other repeater related functions that are still in the menu, but you can't change them.  It almost seems like they took a shortcut and used UV-50Xx software and just tweaked it for this radio. 

 

 

Pros -

1.) Range....  My son and I ran a field test today; both simplex and repeater use.  Anyone who has read my quasi-technical opinion review, knows I was less than impress with what I saw.  That said, going from my BTech mobile to my son's HT inside his car, we easily talked 5.5 miles in rough terrain and while I was on the blind side of a hill, 100 feet+ below the top of a hill and there were lots of trees, buildings, etc. between us.

 

I was pretty impressed that we got that range with my son's radio "inside" his car, while driving, and he was using an HT that has a maximum power of 8 watts.  That was more than twice as far as the results we had with another brand mobile I own... using the same HT.

 

Once we were out of simplex range, we switched to a local repeater.  I am 22 miles from the repeater as the crow flies.  I was using low power (2.5w) WB FM.  My son was 19 miles away from the repeater using the HT, on full power and WB FM.  My son gave me the the same signal report as others.  He said there was some noise on low power, but when I switched to medium power (18w) I was full quite and great audio quality.  Given the RF signal quality I observed with analyzing tools, I am seriously shocked.

 

2.) While the display washed out very easily by the sun light, the display colors are extremely flexible, allowing the user to adjust the color contrast, making it easier to read as well as using font color to further segment the many items displayed on the screen.

 

3.) The owners manual states that the device has a 50% duty cycle.  There is no power level specified, but I assume in low power.  My son and I talked for more than 30 minutes, with most of my transmit time being at medium power and at about 35-40% duty cycle.  During our conversation my son reported that there was no noticeable deviation of carrier or modulation.  My receive quality stayed great the whole time as well.

 

4.) The radio only draws 3.5 amps while using the radio at full power, with the cooling fan running.  The radio came with large gauge power wires.  They are not labeled, but they measure about 2mm.  They are likely 14 gauge, rated for 15 amps.  That's a plus, as you are less likely to have voltage drop over the length of the wire and the fuse will pop long before the wires become a fire risk.

 

5.) While its not very useful for most cars/trucks, it does receive commercial FM Radio.  This is great feature for vehicles that don't have a radio, such as ATV's, older work trucks, construction equipment, etc.

 

6.) You are able to monitor up to 4 frequencies and/or channels at once.  The ability to mix monitoring VFO and Memory channels can be pretty handy.

 

7.) A cool feature that this radio has is, you can sync the displays in pairs of two.  This can be a pretty neat feature.  I set display A (top left) and display B (bottom left) to be in sync.  This means when I change the channel on Channel A, channel B changes as well.  The inverse also occurs.  This allows a user to do things like have the channel Name displayed and the frequency displayed at the same time. You don't have to guess where you are if you are using channel names.

 

8.) This unit displays the DPL code and method on the screen.  This is awesome, because you don't have to guess if your DPL is set or to what value.  Its right there to read.

 

9.) This unit has a feature that is getting more popular; DPL scanning.  If there is a group that is using DPL and you want to be part of the conversation, you can have the radio scan tone squelch and DCS values while the other station is transmitting and the radio will detect the value that the group is using.

 

 

Indifferent -

Something that is not really a pro or con... since we can only transmit on the hard-coded GMRS channels, 225 additional memory channels does not make a lot of sense to me.  I'm sure some will love it.  With the exception of programming the WX channels, I likely wont use any more than that.

 

 

Summary -

Quasi-tech review aside, if you are willing to tolerate some of the technology shortcomings I noticed in my radio (noted in another thread), for a low cost radio, this can be a lot of fun to play with.  Sadly, the display washout is a deal-breaker for me, personally.  However, I think I am in the minority there.

 

In short, I am not going to recommend or condemn the radio.  It's not for me, even with all the cool features.  That said, I leave it to you to use my two threads as a tool to make an informed decision.  I'm just 1 guy with one radio... but there it is.

 

Thanks,

Spaz


  • SteveC7010, cateyetech, Elkhunter521 and 6 others like this


#14743 Used my GMRS today for a practical use case

Posted by krvw on 08 February 2020 - 01:36 PM

Okay, I'm hooked.

 

I was walking out to our local crop share pickup today when a neighbor texted me and asked if I knew what the huge plume of smoke is rising from near Alexandria, Virginia. Nothing (yet) on the news.

 

I had my radio with me because I was doing a couple of antenna/signal tests anyway, so I hopped on the local repeater and asked for anyone nearby to provide a visual situation report. Within a minute, I had 3 separate responses.

 

Turned out to be a huge construction fire, now at 5 alarms.

 

The local news story hit their web site and alert system > 30 minutes later. (See https://wtop.com/fai...truction-site/)

 

No big deal, I suppose, but I will add that from my vantage point, the smoke was along the glide path into DCA (Reagan National) airport. I'm the son of a retired 747 pilot (and fighter/aerobatics RAF team), so big plumes of smoke near airports have always made me uneasy, since long before 9-11.

 

Anyway, LOVE my GMRS comms now that I've learned about the world of repeaters out there. I'll be taking my Ham technician class exam in a couple weeks as well.

 

I'm hooked.

 

Cheers,

 

Ken (WRFC318)

 


  • WQEJ577, n4gix, kipandlee and 5 others like this


#13747 Why "More Power" Isn't The Answer

Posted by WRAF213 on 05 December 2019 - 02:45 AM

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. 


  • Logan5, n4gix, Jones and 5 others like this


#13746 Why "More Power" Isn't The Answer

Posted by marcspaz on 05 December 2019 - 12:37 AM

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 2/3 (or 23) 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 23). 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?
  • Logan5, WPXM352, Jones and 5 others like this


#6658 Boafeng GMRS-V1

Posted by WQYA707 on 19 November 2016 - 10:04 AM

I have two of these radios and have done some preliminary testing. I am a ham operator, and a member of our local ARES/RACES and NET/CERT organizations.

 

Baofeng has taken their UV82 radio and repurposed it for GMRS use. UV82 accessories, including the high capacity battery and AA battery pack, all work with the GMRS-V1. The radios are pre-programmed for the GMRS/FRS and GMRS repeater frequencies, with the repeater offset already set.  The radio will also scan the ham VHF/UHF bands (there are approximately 100 channels available), has a FM radio, dual watch and the rest of the UV82 and UV82HP features. Advertised power is 1W/5W.  The radio is programmable through the keypad and CHIRP; I highly recommend the latter. 

 

Before testing the radios, I cloned one using CHIRP, and made some modifications, including adding the VHF/UHF emergency communications channels for my area. Note that the pre-programmed GMRS frequencies/offsets can not be changed and the radio cannot be programmed to transmit on any other channels.  The GRMS PL tones, channel names, power level, and scanner inclusion can be programmed. Programming is straightforward, as is cloning a CHIRP image from radio to radio.

 

In my test rig, I used an inline power and SWR meter and tested the units with both the stock antenna and a J Pole that that I with my VHF/UHF rig. 

 

VHF power: 2W/5.4W,  SWR (with J pole): 1.1 to 1.5 across the band

UHF power 1.75W/5W, SWR (with J pole)  1.1 to 1.7 across the band

 

Using the stock antenna, low power performance in an treed, hilly urban environment is, as expected, less than a mile. High power performance was between one and two miles. I need to do more testing, with a j pole and a whip antenna to get better numbers. I don't have a local repeater to test against. YMMV.

 

The audio is clear and undistorted. Features like dual-watch, two line display, transmit timer and scanning are handy to have, especially if you are used to using them on a ham HT.  If you have UV82 equipment, the ability to swap batteries, antennas and the like is terrific.  Scanning, like on all Baofengs, is usable but not fast and when scanning, the two line display does not stay synchronized.

 

What I really like about these radios, other than 5W, interoperability with the UV82 and FCC compliance, is they can be set up, the keypad locked so the unit can't be accidentally reprogrammed, and handed to someone without a lot of experience.  I am looking at them for NET/CERT team use and they will certainly become part of my family go bag.  And for less than sixty bucks, including charger, microphone and battery, they are a real deal.

 

 


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#65 A Word of Caution - Posting Personal Info.

Posted by PastorGary on 04 April 2013 - 09:06 AM

We have seen that the Google, Bing, Ask and other search engine spybots are camped out here reading new posts. Just a word to the wise... use your discretion in posting personal or sensative information that could possibly compromise your personal safety, security, lead to identity theft, or give non-licensed individuals a way to access your radio systems.


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#12737 Does CTCSS ruin GMRS/FRS?

Posted by OffRoaderX on 31 July 2019 - 03:01 PM

Its not the tone/CTSS creating the potential issues you mention, it's stupid people that are too lazy to invest 3 minutes of their life to read the directions and learn/understand how their equipment works that are the problem..
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#11312 Duty Cycle Explained

Posted by Corey on 14 March 2019 - 06:10 PM

What does “duty cycle” mean?

 

I bring up duty cycle every time I hear somebody talking about making a repeater out of cheap Chinese mobiles and worse any type of handhelds. Duty cycle is the maximum time an amplifier may transmit within a five minute interval, expressed as a percentage, to avoid overheating. Suppose a mobile amplifier is rated at 30% duty cycle. This means that it may transmit for no longer than 1.5 minutes and must remain off for not less than 3.5 minutes. Some people forget that a repeater is transmitting for 2 or more people, duty cycle will be reached quickly if you get into conversation. More people in the conversation just amplifies the issue.

 

Once a radio reaches it's thermal design limits it will no longer be able to adequately cool the output transistors. Even if a radio is not hot to the touch the transistors are, in part because of the inefficient transfer of heat to the units housing or internal heat sink. The longer you exceed the duty cycle the more heat builds on the transistors, surrounding electronics and heat sink effecting it's ability to remain on frequency without spurious emissions. Exceed duty cycle long enough and you will need a new transmitter or radio.

 

I have tested a few Baofang and TYT radios on my service monitor without great results. All of the radios started deviating outside of the allotted channel bandwidth after simulated conversation at 50% duty cycle, the longer I allowed this the worse if got. Testing was done using an Aeroflex 2975 IFR recently back from the calibration lab. 

 

GMRS is a tiny sliver of spectrum surrounded by the commercial land mobile part 90 service. It is important that any repeaters that are built or re-purposed are held to the highest standards and operated as to not cause any interference inside or outside of our allocated spectrum. I wont get into the part 90/95 debate but i do stand firm that non certified import equipment has no place on GMRS. 


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#9477 Finally ditched the mag mount and drilled some holes!

Posted by WRAA720 on 17 April 2018 - 08:50 PM

Being one of the last cool Saturdays left before summer hits here in Phoenix, I finally got around to drilling and mounting some antennas on the roof of my 2013 crew cab F-150 4x4, 3.5 EcoBoost.  The truck has a sun roof which significantly limits antenna placement. With the sun roof fully open, I was able to place both antennas 12" from the rear of the roof to clear everything. Not ideal, but it works MUCH better than the mag mount I had been using.  Stretches of highway on my commute that were completely deaf to our local repeater when using the mag mount antenna I can now hit easily.

 

Here's the final result:

 

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I picked up a Laird X-ACT hole saw from a local radio shop and it worked great.

 

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Holes marked and masked - measure twice, cut once!

 

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I got a great tip from a fellow AGRC member which was to put down a protective layer above the headliner when it was dropped down in order to catch all the mess from drilling and sanding; I laid down an old towel on top of the headliner before I got started. I used gorilla tape to keep the coax from flopping around, and ran both cables behind the rear passenger side airbag (super important!), down the rear pillar and under the door trim up to the center console.

 

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Antennas installed - in the photo is a Laird QWD144 1/4 wave 2m on the right and a Larid BB4502N 1/2 wave UHF for GMRS on the left:

 

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I also have a Larsen 150/450/800 on the front fender for my scanner:

 

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I currently have a Uniden BCD996P2 and a Motorla CDM1250 installed in the truck; an Kenwood 2M rig will be in there soon:

 

FMQElXD.jpg

 

Action shot!

 

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#5570 Weekend tower work.

Posted by Corey on 10 April 2016 - 09:52 AM

Not GMRS but still UHF radio related and I know several other members own or service licensed part 90 systems. So I thought I would share a few photos from this weekends tower site repair on my business system. Last year I added this site to my Mototrbo IP site connect system, because of costs I cut a few corners and paid the price with an under preforming site. Today's project included installing the new repeater system, replacing the antenna, upgrading from 1/2 to 7/8 feed line and swapping out the 2' standoff for a 4'. Big thanks to my climber, he braved the 29 degree temps and completed the entire project in 4 hours. Yes that's him sitting out on the end of the 4' side arm installing the new antenna. I guess the side arm is now climber tested and approved! Not even with his 50 lbs of safety gear would you catch me sitting out there at 150'. I did some testing on the 50 mile ride home and the site is no longer under preforming. It has exceeded my predictions with15 miles of portable coverage, up from 2 miles.

 

dmr1.jpgdmr2.jpgdmr3.jpg

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#14201 MURS Signal

Posted by Jones on 07 January 2020 - 10:30 AM

I hear DTMF tones all over Nebraska on MURS.  I looked into it a year ago, and found out that several farms in the area use MURS for a remote monitoring and telemetry system for their crop irrigation systems and water wells.  There is also at least one company making MURS remote alarm systems for farm buildings and gates.

 

MURS is legal for all of those kinds of things, so that's likely what you're hearing.

 

Most people using MURS for these types of operations do not even know what frequency or band they are using.  All they know is that they purchased this wireless thing that lets them know back home when someone opens the pasture gate, and they have another wireless thing that tells them how many gallons per minute the pump is flowing.


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#14074 Right under our own nose...

Posted by WREN301 on 29 December 2019 - 01:39 PM

I just received mine and have had it a couple of days. Have compared it to the BTech GMRS-v1. This radio blows it away. RF performance is amazing and I can hit all of my local repeaters from inside my house. One of them almost 30 miles away. The circuitry is way superior to the radio on a chip unit. Wish the buttons were rubber instead of hard plastic. Screen viewing angle isn’t that great either. But the little cosmetic flaws aside it’s RF performance justifies the cost completely.
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#13752 Why "More Power" Isn't The Answer

Posted by RCM on 05 December 2019 - 11:38 AM

... 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 23). 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.

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.


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#13659 New Online Store

Posted by WQEJ577 on 28 November 2019 - 09:25 PM

Happy Thanksgiving! Hopefully everyone's bellies are full and you're spending time with your friends and family.

 

Now that we're heading straight into the holiday season, I wanted to mention that we have launched a new store. Previously we had a Spreadshirt shop which only sold t-shirts and similar apparel. Now, we're expanding into other categories such as radios and radio accessories. Many of our Spreadshirt items are available on this new Shopify store.

 

We're still working on dealer arrangements with some GMRS radio manufacturers, but in the meantime we have a great Black Friday/Cyber Monday deal: 20% Off your order of $50 or more! Just use the discount code BLACKFRIDAY19 at checkout.

 

If you have ideas for products or designs we should carry, please let me know! 

 

https://shop.mygmrs.com/


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#13231 So I heard something that sounded like Motobro or DMR.

Posted by quarterwave on 19 October 2019 - 08:02 AM

GMRS requires a user license, FRS does not. FRS "Rules" are generally non enforceable.

 

 'FRS is licensed by rule. This means an individual license is not required to operate an FRS radio provide you comply with the rules. You may operate an FRS radio regardless of your age, and for personal or for business use if you are not a representative of a foreign government.'

 

And you are right...businesses need to be on MURS if they want cheap comms. 

 

Maybe the good thing is that most of the cheap radios that people buy from a "store" are good for 2 watts at best. Really what was done with the rules was to make what people were (uneducated about radio) doing illegally with store bought radios that did GMRS and FRS in being legal. The fcc should have never allowed combo radios to begin with. 
 


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#11294 Can GMRS repeaters be linked to the web like Echo Link for hams?

Posted by Corey on 13 March 2019 - 07:01 AM

How do you get in on this network?  And are these point-to-point links, or some kind of national or regional network?

 

We are using Asterisk as the server (running on a raspberry pi 3) and the RTCM made by micro-node. Cheaper hardware solutions vs the RTCM are available but require other configuration. I have not used any of the other hardware so I wont touch on that. I chose the RTCM for its single unit design and application specific properties. The interfacing with the RTCM is rather simple, I went with the MTR2000 repeater for reliability, full duty cycle and used market availability. 

 

Our group hosts its own local node server (Asterisk running on a raspberry pi 3) with 6 repeaters connected to it. This local node also allows us access to the MyGMRS national linking network hosted by the owner of this site. By entering commands in Asterisk or using DTMF,  links to other systems can be connected or disconnected on the fly. Things like usage counters and the visual map show links with red lines as well as what site is transmitting by changing its marker from green to red, all of this in real time.

 

Its not as hard as it sounds, Rich from MyGMRS was a huge help, you can also find a linking thread in the private section here. Along the way I found a company that was able to build a custom cable for interfacing the MTR2000 with the RTCM, it provides a reliable solution that's repeatable and works flawless. The MTR2000 repeater can be configured to work with the RTCM rather simply using the repeaters wire-line card to handle the audio and the 96 pin J5 connector to pull ctcss, core, ptt and power.

 

We are using the RTCM and MTR at 6 sites with a stand alone MTR at a 7th and could not be happier. These machines are worth every penny, its not 2 mobiles in a box its a true full duty cycle, commercial grade repeater. Due to the simplicity I have several more RTCM / MRT2000 combos ready to go I just need to fined a few more tower sites with internet.

 

Hope this answers a few questions.


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#10876 BRRRRRRR.......

Posted by PastorGary on 26 January 2019 - 05:47 AM

5 AM Central Time, Saturday, January 26 - 14 degrees below zero with wind chill at 27 below zero. Colder at my Midwest location than in Fort Yukon, Alaska.

Several years ago, the morning air temperature was 27 degrees below - a lady went out to her car to go to work, saw that one tire looked a little soft - kicked it and it 'broke'.


It is so cold here that Scotsmen in the area are starting to wear pants. I tried to take the garbage out, but it didn't want to go. Pet stores here are starting to sell Penguins. Police told a robber to freeze - and he did. Mail delivery persons are watching out for dogs AND Polar Bears. It is so cold here that hitchhikers are holding up pictures of thumbs...

 

Now, where did I put my golf clubs?


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#10406 Happy Thanksgiving from the volunteer staff at MyGMRS

Posted by PastorGary on 22 November 2018 - 05:52 AM

We hope that everyone has a Happy Thanksgiving holiday. Please use caution if you are traveling - especially in areas of the US that are seeing abnormally cold temperatures and freezing precipitation.

Have a good day and be safe.

 

- - - - - - - - - - - - - - - - - - - - - -

 

The MyGMRS Moderator Staff


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