PACNWComms

If it was digital TDMA (Time Domain Multiple Access) in use that you heard, you would heard the flutter on nearby AM radio. I often demonstrate this with an AM Citizen's Band radio (Cobra 27 LTD Classic) with the volume turned up, and key up a UHF DMR radio nearby. You will hear the flutter of the time slots back and forth, rapidly switching between two effective channels (I use an older Motorola XPR6550). In many cities FRS/GMRS and digital DMR radios are often heard, and it can be fun to listen to analog radios with a cheap old scanner.

Always nice to see the younger generation join in. Radio is not going away, as many in my profession have said numerous times over the years. There is actually an ebb and flow of shortages, with another one coming in the next 5 years or so as the current generation retires. When possible, I always recommend amateur, and General Radio-telephone Operator Licenses as that opens more doors to employment. Great job and good luck in your club.

Thank you for sharing. May get another DB20-G myself. Bought one a month ago and it works great. Really does put out 20 watts, and works very well on both VHF and UHF. GMRS use has been great. Being so small, it fits newer vehicles well too.

If it was 100 or even 50 feet then that would be another thing......a few extra feet is usually left in vehicle and vessel installations by the pro's for repairs and new connectors. In many cases testing is done on a yearly basis, and connectors get broken, corrosion may require a few inches of coax to be cut off, and some extra is necessary in that case. Do not worry, as others have mentioned about a few extra feet. 6dB gain in the antenna will easily compensate for some coax line loss. An isotropic (perfect antenna) would mean a spherical radiation pattern, 3dB would be more like a doughnut, 6dB more like a pancake, and 9 dB more like an LP record.

I have been watching both of these potential changes for a while now on another website. Administering a large radio network with semi tractors equipped with both Motorola commercial radios, FM and 40-50 Watts, and 5 Watt Cobra CB radios that are built as cheaply as possible, the FM CB idea may help with voice clarity and overall usability. AM has forced technicians to make a clean and efficient install, and users to bring them in for a watt-meter test when they suspect a problem. As for location on GMRS, I have wanted this ever since taking a Garmin Rino 120 to Afghanistan in 2004. Many of us bought them for augmenting the Rockwell PSN-11, being careful about the location sending feature. Garmin's first series of Rino radio/GPS receivers were in many people's pockets, as they had a map, and were even olive drab green in the 120 model. That location feature helped a lot as well in certain situations......adding this to a higher power GMRS and mobile radio would be great. Hope it happens.

I have been in this position for a while now, having a Technician class amateur license and Restricted license (as well as GROL) for vessel and aircraft......keep wishing I had stayed for the next test. However, where I took the test,I did not exactly want to stick around much longer.....there were definitely some "personalities" at my testing location. I run into some of them from time to time, me working in commercial radio, with a little public safety related, and many amateurs wanting to assist but not wanting to put the time in for organized drills. Good luck on your tests, and actually using radios. I know many that have the license that never transmit, they just wanted a piece of paper to put on the wall.

I went and got my GMRS license on the basis of cheap Chinese radios being available that were small enough to fit in the cubby holes of the daily driver car. My previous car had stacked Vertex VX-3200's (VHF and UHF) in the dash. New vehicle just does not have the room for Vertex or Motorola commercial mobiles. Then ended up going full tilt and using both a CDM1550LS+ and a XPR5550e for GMRS base stations. As another said above, watch out on the specific CDM series model you buy, for output power and flash (applies to XPR Trbo series as well). Noticed some people bought CDM1550LS+ as they have a full keypad on the faceplate, but some only have 16 conventional channels and the auction may have mentioned 160 (in trunking mode), or some other sale pitch. Buyer beware. But great for GMRS.

Bought a couple of these from Tessco a long while ago. Use them in the attic mounted to New Motorola (NMO) magnet mounts on baking tins attached in the attic. I do not get up there often,but have had magnet mount antennas in the roof/attic space for 13 years now. Work freat for UHF in general and GMRS RX/TX is about 18-26 miles. Being rated at 200 Watts, they do not get warm at 50 Watts. PCTEL's BMWU4002S Maxrad 380 – 520 MHz wideband 2 dB with ground plane/unity gain without black antenna with stainless steel spring 200 W. Order Motorola style mount separately.

Power out and SWR should also be checked from time to time, or if something changes in your equipment. With anything that moves, vehicles, vessels and aircraft, movement leads to wear and failure. I have had many state that their radio "just quit working" only to find a broken connector on a cable, damaged or missing antenna, or corrosion that has worn a cable. A good rule of thumb is to check coax (and antenna and radio) by placing a meter in line and testing once a year at least. In many commercial/municipal/government uses, this is required and spelled out in contracts, and is a compliance issue.

While working on loan to the Department of State in a previous life, I always thought it interesting that they issued and stored slightly modified versions of Tecsun PL-360/365 and now PL-368 receivers for emergency preparedness. This of course was in addition to the food, water, weapons, and other items (in a foreign country that was at war at the time). The radios were receive only, and for use to listen for emergency messages, and when to leave if it became necessary. I thought the receive only part was odd, as a transceiver is much more useful, even if more expensive and requires more knowledge to operate. My emergency plan includes both receivers and transceivers, with cheat sheets and guides included with the radios.

Used several Vertex VXR-7000 repeaters for remote site use for oil spill response efforts. With the rack mounting kit, they work well with SKB cases, with space for a duplexer, power cords, some antenna coax, and power strip. The only issue we ever had was when a small radio shop attempted to add a 50 Watt amplifier to one, and it never worked the same again. We ended up replacing it with a Motorola XPR8400 which can be found along with the XPR8300 on the used market for reasonable prices. They had a fan issue on early models that was later fixed, but are solid repeaters as well.

Lithium Ion batteries are the big issue with aircraft and radio equipment. Some aircraft incidents have been a direct result of high density battery failure, sometimes built into the aircraft, or some device brought on board. As for use, even though emitters are tested by aircraft manufacturers, there is often a combination of legal issues and technology impacts that drive policy for use while aboard aircraft. For those that order radio batteries in quantity, you may notice large labels that mention ground shipping only, or cargo aircraft only. That being said, I have carried everything from a Motorola Talkabout FRS/GMRS handheld, Garmin Rino GPS/radio, and many XTS/APX series radios on board aircraft. Often times TSA just looks at me like I am some amateur enthusiast as I might have a radio better than the one on their hip. The only odd look and pull aside was when I had a Harris Unity XG-100P when they first came out, and a TSA agent asked questions, like when he would be getting one.

Another option is to find an old scanner. While many public safety systems are digital (P25 Phase 1 or 2 or both) there is a lot that is still old school analog. AM aviation 121.5/243.0MHz, amateur/FRS/GMRS calling frequencies, wireless devices, and 88-108 MHz broadcast radio. Get something with push button programming, PLL circuit, and a decent display. Think Radio Shack Pro-2032/2004/2006 that does AM/FM and VHF/UHF and there will still be a lot out there to listen to. Sure, a phone application works, but loses some of that "radio" aspect. I have found many handheld scanners at thrift stores and yard sales, where the battery compartment just needed to be cleaned out with DeOxit. Add new batteries and it was back in service. Even in 2021, there are many "retro" aspects of a desktop or handheld scanner from the 80's-2000's that still appeal to many. Most areas have an airport, FRS/GMRS analog radio on UHF, and some VHF transmitters that can be heard. Make it a contest how many different channels/frequencies/people can be heard in 5 minutes, or a specific area.....get creative, and good luck.

+1 on the aluminum part. In a previous life, I worked around ionizing radiation, and many knee jerk into thinking that lead is the only shielding that works. Borated concrete and aluminum work well for ionizing radiation. Aluminum skinned aircraft and spacecraft work just fine, even with RF equipment on board, and with each radiating around each other, if it is engineered to work together. RF radiation wise, my biggest job was where a fleet of ships had been retrofitted with Icom IC-M602 VHF marine radios, and a few IC-M608 VHF/HF combination radios. These are plastic cased radios with rear aluminum cooling fins, and very little RF shielding. They do not work well together on the bridge of a ship, even if spread twenty feet apart or more. They were intended for pleasure craft, where only one radio was needed. Fast forward to me delving back into FRS/GMRS territory, and I am relieved to see many GMRS radios built with full metal enclosures, such as the GM-30 handheld and DB20-G mobile radios. Connected to a good antenna, coax, and appropriate connectors, an aluminum roof rack is going to work just fine. You will most likely have to worry more about physical damage should you place items in the rack. Be sure to let everyone know how it works out for your particular installation.

Had several XPR8400 repeaters in use myself for a corporation that responded to oil spills. Worked well, but had an issue with the fan going full speed, often damaging the fan. This was able to be rectified and adjusted. They also allowed for mixed mode use, which was great for a corporation that planned to go to 2 slot TDMA Trbo in the future. As for MTR2000-MTR3000's, I have also had several power supplies fail on these models of repeaters in the past few months. Parts are hard to find, and Motorola is ending support soon of the MTR3000's. The MTR3000 is also a transition model that could do analog conventional and 2 slot TDMA, much like the XPR8400, which also came with that feature. If you never plan to use digital mode, the XPR8300 may be a cheaper and more available option. As others mentioned, the current SLR5700 (50 watts) and SLR8000 (100 watt) repeaters are a considerably better option, but at new prices. If it were me and digital was never expected to be used, I would look for a slightly used XPR8300 repeater for GMRS.

Metal roof racks will impact antennas, both electrically and physically. How much depends on the antenna, placement and construction of both the antenna and the roof rack. However, with some vehicles, such as aluminum skinned Ford F-150's, steel roof racks often help, increasing the ground plane for the antenna. However, real world.....unless you are trying to get the perfect signal out of your radio/antenna/vehicle combination, most people will not notice the impact of a roof rack. For UHF and GMRS, I would not worry about it too much. As for RF exposure, I try to meet the FCC guidance, keeping several feet between UHF antennas and people inside the vehicle. For that truck/SUV, putting an antenna near the back of that roof rack, or on the roof rack, above the rear light would be the most useful and least impacted by the roof rack. This also places the antenna at a high point, extending range. But, depending on length, may be an issue in garages and decked parking lots.

Recently bought a combination package of Radioddity DB20-G mobile with a GM-30 handheld GMRS radios. Both work as expected, as described but with terrible manuals, the need to download software from the Radioddity website, and get the correct drivers for the programming cable. However, the DB20-G does actually put out 20 Watts, as checked with both a Bird/Thruline wattmeter and a Surecom dual band wattmeter. The GM-30 is very similar to many other Chinese made handheld radios of the past decade, and looks a lot like my Anytone 878 handheld. However, the DB20-G fits perfectly in an old Honda Civic dash cubby hole, looks like it came with the car. A Tram dual band antenna went on the trunk. The TYT, Anytone,Radioddity radios appear to work well. I may do as a previous poster mentioned, and buy more DB20-G radios for use in other vehicles, and as base radios where I do not want a larger power supply and Motorola CDM or XPR series mobile dominating the desk space.

In my trips to Washington and Oregon, I seem to pick up many MURS radios in use near canneries on the Columbia River and Puget Sound. Audio sounds great, and some workers have been carry what looked like old "dot" red, green, etc type radios. These are areas where some volunteer firefighters still use Motorola HT750/1250 handhelds. Would not surprise me if there were some old school Maxtrac's and a former Radio Shack store in some of those towns.

Notarubicon is how I ended up here. Started with getting a GMRS license, then new radio equipment as my older FRS/GMRS gear consisted of Talkabout Motorola's and Garmin Rino's. Next came a Zello account and applications on PC and phone, then Notarubicon chat.

Why I joined, to see if there was anyone else in the area. Definitely looking for more activity in the Pacific Northwest. I know FRS/GMRS is used often in WA/OR/ID, but have experienced more users in Montana. My time in Seattle has shown that the UHF spectrum is saturated, with FRS/GMRS being almost constant. Actually interfered with a lot of commercial UHF testing as a result. Will be checking this thread from time to time.

Having used DTR series Motorola radios for many years now, I try to keep up on new versions. Thank you for posting, this could be an interesting new product line.

Using many DTR series radios in large warehouse style buildings, I also looked into this. The deal breaker for my use case was the one TalkGroup/Channel per "repeater" which would just become too expensive. Even older DTR410's manage to hit about 90% of the warehouse areas, cluttered with metal structures and machine hardware. 900 MHz ISM band radios have their place, but also limitations. If anyone does figure out how the range extender works, it may be worth re-visiting. I have yet to find anyone that has implemented one of these in the real world yet.

Have been using DTR series radios for many years now (Motorola DTR410's to start) and they work extremely well. However, as others mentioned, many use them right out of the box, with defaulted settings. I have a barge crew operating in a river nearby that uses the first channel default settings, and it is probably a good thing that their range and capabilities are limited. Otherwise, great radios and very "secure" comms if you set up your own private channel.

Great to see this information up front and on top. I have administered P25 radio networks for a very long time, and repeaters are not for the newcomers. I have built portable repeaters for use in the aftermath of hurricanes: Katrina, Rita, and Wilma,and for incidents such as the 2010 Deepwater Horizon (oil rig) explosion and resultant oil spill response. All of the advice given here is spot on. Repeaters are after you gain some experience running "barefoot"and simplex for a while.

New GMRS license holder, but not new to FCC licenses overall. Just needed another radio in my commute car, and this was the cheap, easy, and fun way to go.