Radioguy7268

The EVX-R70 has better specs for the receiver, it has a bigger (better) cooling fan than the 7000, and it also has an added heat sink on the transmitter. It will also do DMR Digital or work as conventional analog. As JohnE alluded to, it's really just a re-badged Motorola XPR8400 machine - but uses different CPS software. (make sure to toggle the software setting to 'expert' mode if you want to see all the parameters available.) That said, for all it's good qualities, it's still really just 2 XPR mobile radios inside a box. I've been happy with the EVX-R70's I've set up. It's also nice that you can buy the EVX-R70 used for 10 to 25% less than the same thing with a Motorola label. The EVX-R70 is good and reliable for "regular" service - but they're really not 100% duty cycle 24/7 machines. I would never run one over 25 watts if I wanted it to live for years.

There is no Front Panel Programming mode on the Motorola CDM radios. You need to have software & a specific programming cable in order to change the programming that's already in the radio. Changing the tone on an existing channel is about a 10 minute job, start to finish. Getting the correct software & cable is much more of a job than doing the actual work. If it's a one-time change, then it's probably more cost effective to pay someone else to do the programming. Without knowing where you are located, hard to recommend somewhere local to take it to, but I'd start by searching for "Motorola radio dealer +_________________" and fill in the ______ with your local city/metro/county location. There are people advertising programming services for those radios on Ebay starting @ $30 + return shipping costs. CDM's are fine radios with good audio and decent build quality. They were at the pinnacle of analog radio technology 20 years ago.

If you're focused on getting 'max power' out for Transmit, then I need to ask, what are you talking to on the other end? If you've got 4 or 5 watt portables, transmitting at 25 watts (and setting aside any antenna system gain/loss for a moment) creates an imbalanced system at best - and generates a bunch of unnecessary interference to your own receiver at worst. In other words, if you can transmit out 15 miles, but your portables can only talk back in from 5 miles, what have you accomplished? Balance to the system is the key. As gortex mentioned, filtering the receive side is probably more important, but most advertising will focus on the 'horsepower' number, because that's what sells. Any rookie will pick a 50 watt transmit over 25, because more MUST be better. It's just one number, and transmit power rarely tells the whole story, especially when it comes to repeater system performance. Losing 1.5 or 2 dB to gain 60 or 70 dB of isolation is a pretty good trade off, and if you put a bandpass cavity tuned to the receive frequency on the receive side of that cheap duplexer, you're going to pick up even more isolation without increasing any losses on the transmit side. I can tell you that my basic rule of thumb for a generic repeater is to shoot for double the power of the portables being used. You're well above that at 25 watts, and I'm not aware of too many low cost repeaters that will do an actual 100% duty cycle at 25 watts. There are plenty that will approach 100% duty at 10 watts with a good cooling fan. Until you've got a quality receiver with decent filtering on the receive side of the system, it really doesn't matter how much power your transmitter has. Isolation, selectivity, and sensitivity are all more important than raw transmit power when you're looking at a repeater system.

Man, we argue about the benefits of 25kHz "wideband" vs. 12.5 with GMRS. I can't imagine stepping up to a minimum bandwidth of 500kHz! Imagine the fidelity... then again, you're still power limited, and you would need to accept any interference. I think for practical purposes, even if the rules don't spell out a particular protocol that you MUST use for the ISM band, reality is that you're going to need to use spread spectrum to have success.

Practicality is the most simple answer. SAR is the more complicated answer. Battery size and battery life are the limiting factors regarding transmit power. Sure, you can jack your small hand held portable up to 8 or 10 watts, but how long will your battery last? Does a 10 watt transmitter become a feature or a liability when your battery life is measured in single digit minutes? Nothing holds anyone back from putting a 50 watt mobile into a backpack and strapping it to a 12volt battery, but at that point, you're losing some of the portability. Plus, where are you going to find a ground plane for your 5dB mag mount antenna?? The SAR (Specific Absorption Rate) is more complicated, but basically it's a measure of the amount of Electromagnetic radiation that's being transmitted (and absorbed) near a human body. SAR measurements for hand held devices (portable radios & cell phones) has been part of the Type Acceptance process with the FCC, but they've also recently taken a more active look at regulating amateur hand held devices: SAR writeup in 2021 ARRL Most newer commercial portable radios now carry a tag like this one, limiting the device to being used for "occupational use only" Not sure how long ago those started showing up, but it's only been in the last few years that I've noticed the labels.

Motorola did make a telephone style handset for the MCS2000 series. They still make a similar style handset for the XPR Trbo series mobiles - P/N RLN6252A. Not sure what the Part number was for the MCS2000. They promoted it as a 'privacy' handset, because once you picked it up out of the cradle, the receive audio switched to the earpiece of the handset. We installed a few in Limo type vehicles back in the day - when the drivers were still radio dispatched, and the VIP's in the back had their own 1st generation analog cellphone mounted in the rear console.

Go look at FCC Part 90 rules for Station Class Codes. That's where you find the definition for some of the terms that the FCC seems to like using for GMRS without defining them: FB= Fixed Base using a single Simplex frequency for both transmit and receive. In GMRS this would operate on the lower 462.xxx side. FB2 = Fixed Base using duplex frequencies (1 to listen, 1 to transmit) more often called a Repeater. FB4 = Shared (community) Repeater with multiple user groups. FB6 = Private Carrier repeater (airtime for rent) FB8 = exclusive (protected area) license for Trunked system. FX1 = Fixed Station - transmits on the repeater's uplink (ie: 467.xxx MHz) from a stationary location. Folks often call that a Base station, but it's not. A base transmits on the lower side of a frequency pair. People in the industry also call an FX1 a Control Station. MO = Mobile. Mobile can transmit on either the low side (simplex) or the high side (simplex or duplex). As the name implies, mobiles can move around, and they can be either hand held portables, or vehicle mounted mobile radios. And yes, the FCC should define all that in the GMRS Part 95 rules. They seem to be playing fast & loose.

Except that the RT81V isn't accepted/type certified for MURS. If it was, it would have a fixed antenna, max 2 watts and just 5 frequencies. Thus, the bend. In reality, the MURS world is a free for all with all types of 4 watt portables being programmed up on those channels as simplex users. I see that with the FRS channels in UHF also.

The Vertex EVX-R70 is the clone of the Motorola XPR-8400 repeater, but you need to use the Vertex Standard Clone Editor software. The most recent version of that should be Version 5.5 (build 34) from around 2016. If you want to use it in Wideband mode, you should probably use the "export" version or "emea" international version. If the repeater was updated and/or written with newer software, you could have trouble reading it with an older version of software. Vertex software is still available for download from Motorola if you have user credentials on MOL. What cable are you using? What version of Windows are you using it with? Can you see the cable that you're using when you go into Device Manager & look at your USB ports? Does the radio show up as a network connection when you plug in the cable? You should get tones when you plug in (or remove) the cable from the USB port if you're set up with the right drivers.

You've got to be kidding me. IF the USER speaks their Call Sign, then that is what's transmitted over the air. In GMRS, there is NO Call Sign assigned by the FCC to a Repeater. There is no Coordination with GMRS, and there's absolutely no correlation between the physical location of a repeater and the mailing address of the Licensed user. You are making up rules & then trying to find places to apply them. Stop.

That's a warped interpretation IMHO. A repeater that does not have CWID can just have the individual users stating their own Call Signs in plain English at the required intervals, and no laws have been broken.

Unless you already own a GR1225, it's usually not worth spending good money to buy one IMHO. For similar money, you can get a newer XPR8400 (Or Vertex EVX-R70 ) and for not much more, you can get an honest to goodness real 100% duty cycle MTR2000 that will put out 50+ watts all day long without burning up. There's a lot of burned up GR1225's that end up on eBay, and even at their best, they were never going more than 25 watts if you wanted them to live.

Trident had their own terminal program called Tcomm. I have a copy of it around somewhere. As I recall, it was from Win95 era, but would run on WinXP. I would NOT recommend using a Trident Raider panel unless you've got a copy of the manual (along with a few hours to read it). Trident was selling those for LTR use, and as I recall, you have to assign the user an LTR ID# - but then tell the panel that particular ID# was going to be using conventional PL or DPL - and then use a translation table to assign the particular tone code parameters to that ID#. I can tell you that the Raider panels are reliable - I still have a few in service that are approaching 25 years with zero problems. i20r panels still pop up now and then on Ebay. They were nice to use with the GR series repeaters, but I wouldn't spend big bucks to flog a GR300 back to life. There's better alternatives out there nowadays.

If you never programmed a radio before, the CDM series might be a little difficult to figure out. I even had one competitor pay me to program their customer's HT750 radios back in the day because their tech couldn't figure it out. There is no real "step by step" manual ever put out by Motorola that I'm aware of which covers the programming of radios. They do offer some training online for for shops who sign up (and pay) for the training, but I have usually just spent the time to figure it out. PM400 or M1225 radios are a little easier to work with for basic setups using the RSS/CPS programming software. Once you get familiar with those, then the Professional Series is just a step or two beyond. Most Radio Shops will program up a radio for you at a reasonable price. If you're the kind of person who doesn't make themselves a pain, the shop might even let you watch while they program in a channel or two. It's not rocket science, but there's a few gotcha's involved.

Call your local 2-way radio shop. Shops like mine sell good used Motorola or Vertex analog UHF mobiles all day long at under $200, tested, tuned, and ready for install. We don't bother with eBay anymore due to all the seller fees and payment charges.

A typical "notch" style compact duplexer (the ones you usually see advertised at prices around $100) can have a really wide and lousy tune job applied - and will "cover" the whole GMRS band, but they won't do it very well. If you're OK with having 3-5 dB of desense - then yeah, go for it. It will halfway kinda work as long as you've got a strong signal into the repeater.

The Nextel 3rd generation (last generation?) phones had a built in FHSS 900 MHz "off network" radio they called Direct Talk. It is NOT compatible with the DTR/DLR series of Motorola radios, even though it's the same technology. Not sure what in the protocol was different, but I'd imagine it's beyond a simple secret hopset number, or else that info would have leaked out to the public by now. There were a few Nextel phones like the i375s which had an external antenna and were ruggedized. Those seemed to be the units with better range on 900 MHz Direct Talk, but I never did a side by side range test with DTR series vs. the Nextel models.

If it is Fire/EMS voice paging (with tones) - then I would be betting that some nearby Volunteer has put up a budget cross-band repeater to send out their county dispatch/tones on an FRS channel. Do you ever hear voice replies on that same channel? Or, does it seem to all be one-way traffic?

Wow - what tangled answers to a simple question. YES! You can use the EVX-5400 for GMRS! It's a nice little radio. The software does not require a wideband entitlement key like Motorola CPS. You just use the Export or "international" version of the Vertex software. If the radio was previously written with the Narrowband only software, you will need to "unlock" the radio with a special Vertex software module called the "Wideband Recovery Tool" version 1.03 If you're trying to recover newer Vertex radios like the EVX series - you're going to need Version 1.03 of the Wideband Recovery Tool. That isn't easy to find online, and you also pretty much need to invest in the FIF-12 programming box/cable setup from Vertex to make that work with newer radios. The FIF-12 runs about $150 to $200 new. I could unlock it for you for about $25 if it's a one time service. Any other Vertex or local LMR radio dealer could probably perform the service for you also at a similar price. There are also 2 different versions of the EVX-5400 radios. Older models had a 8 character display, the newer versions had a 16 character display. The CE-151 export software should be used with the newer (and more common) 16 character displays for Wideband operation.

Have you ever used that same software to read another Kenwood radio? Has the programming cable ever been used to read/write? Not sure why you can't type in the box, but beyond the "where did you get the software?" question - you've got a radio that you can't read or write to without a password. I wouldn't throw the seller under the bus right away, but if the radio was sold on Ebay as "used" - and it's got a password that prevents the radio from being programmed, then it's up to the seller to provide a password and fix the problem or refund your money. If it was sold under "Parts, not working" then it's your problem.

If you think it is illegal, then don't do it. If you are saying that since All-Star is based on *asterisk (which is an IP based PBX) it fails because it's using telephony to connect repeaters - then please tell us how many people have been cited by the FCC for using "ilegal" All-Star. I think you will find the number of citations is Zero or less. By the way, nice first post.

The best way to know your cable loss is to measure it. Not always practical when you're stringing 150 ft or more of hardline directly from the spool onto a tower, but for most of the GMRS mortals, it's in a coil with terminations installed prior to us heaving it up onto a pole/tower/rooftop. If you know the input power, and can measure the output at the other end before it is hoisted and connected to the antenna, then you can calculate/know your own losses easily enough. I say that because while the manufacturers do tend to post numbers grounded in reality, the various distributors can get a little creative when it comes to their claims. Rounding up, rounding down, convenient lapses in stated lengths (oops, it was 1.5 dB per 50 ft, not 100 ft.) can all make a difference. I've seen some knockoff brand RG400 jumper cable assemblies that had nearly 3 dB of loss in a 5 ft. jumper. It should have been less than 1 dB even including the connectors.

You are correct about the outer pins - they can be pretty much ignored, and the center 16 pins will follow the standard Moto conventions of Radius mobiles. Be aware that the CDM radios will not fit in the stock GR300 housing - the control heads are too big. I've seen people just screw in a mobile mount at the top of the GR300 housing for a cludged look. Also, you really should wire in ignition sense for the CDM mobiles - as they will not automatically restart with loss/restoration of power otherwise. Not a big deal if the repeater is on your desk, but a PITA if the repeater is at a remote tower site. One final consideration for the GM300's - consider finding yourself an old-timer "Elmer" who might already have all the cables/software/knowledge for programming the GR300. Even if you pay him $50 for the trouble or buy him lunch, it's still cheaper than buying a set of used CDM's. Most commercial shops won't touch a 25+ year old repeater for anything other than a trade-in, but the guys who work there probably have the tools and knowledge to do the job if you get on their good side.

CDM's can work - but there's a learning curve with the CDM models. You also need to be real cautious with buying those off Ebay - as there are a ton of CDM radios that have been hacked and cracked. Things like LS+ trunking models that have been flashed over to conventional.... or LS models that only do 16 channels in conventional mode, and can't do MDC. Personally - I'd tinker around with DOSBox for a GM300. The trick that worked for me was setting the "CPU Emulation" to act like a 386. The rest seemed pretty much standard. I have been able to program anything from Radius M300, M120's, SM50's or GM300's.

Cane wireless makes an FHSS repeater setup for DTR radios - http://www.canewirelesspro.com/drx-repeater.html I've never sold one or played around with one, but looks like about a $3000 solution. Need to buy two of their boxes, and separate them with at least a 20 ft length of ethernet cable connecting the two boxes. It appears to be bidirectional to me. One DRX radio receives a particular talkgroup/code - then the 2nd DRX radio re-transmits on a different group. It appears that you would need to have a portable DTR that's set up to scan talkgroups in order to talk back & forth.