Radioguy7268

It's funny that you're using the wording to create a rule that applies to "family" when the rule in question does not use the word "family". Perhaps you think that is what the rule should say? It also does not say "individual's license". If it did have that apostrophe, then it might actually mean a License that belongs to a particular individual. I still read it as saying that if the individual operator(s) of the repeater use their FCC Station License Call Sign, the repeater itself does not need to identify. You may disagree - and that's OK. What anyone here thinks doesn't matter. What the FCC thinks is what matters, but I think they don't really care.

Don't let science get in the way of advertising. More watts is always more better! Who needs a receiver? I got 45 watts out, a cigarette lighter plug and a mag mount!

I admire the thought of chasing down electrons and actually fixing the device. Somewhere, there's a manual and schematic for those radios. It's probably written in Chinese. I can't imagine that anyone's going to go to the trouble to translate it and produce some copies that would probably end up costing more than the radio it's written for. Practicality is the reason you don't see repair manuals for radios that cost less than $100. Do a little searching on theory & find some schematics online for a portable with similar finals. If you can identify the components, you're probably looking at something like a failed solder joint. At least, that's what I'm thinking when I hear that it will still push out at least 1 watt.

... and you will also find out that every normal DPL code has (at least 1) matching invert, which is really just another number on the DPL chart. So folks who (over)think it and decide that they're getting some type of super special "secure access" on their repeater by choosing some odd-ball Inverted code end up baffled when someone sniffs out their code over the air within 30 seconds. Inverted code/matching std code 023 047 025 244 026 464 031 627 032 051 036 172 When you're dealing with digital ones and zero's in a streaming bit code, the patterns end up repeating themselves, even if your bitstream originally started with a 0 instead of a 1. Someone with more patience and knowledge explained it better than me, but if you want to go for a deep dive - here it is: DPL demystified

Definitely - the CCR's (Inexpensive radios using Direct Conversion single chip design) have sensitive but not selective receivers (ie: Wide open to any and all other nearby transmitters). Those types of inexpensive radios have receivers that are easily overpowered due to their lack of filtering. You would be MUCH better off to buy a used LMR radio that has a really good specs for selectivity and sensitivity. Decent used LMR stuff is available at less than $100 per radio - especially when you don't care about the transmit power. At 20 ft of vertical separation, you would still need some type of a bandpass cavity for the receiver. Get more than 30 ft. and your difference between the transmit and receive coverage begins to get out of hand, not to mention the cost of getting a real sturdy mast that can stay up at over 50 ft. - just so your lowest antenna is still 20 ft. off the ground. There's a chart out there on the internet that's been posted here before, showing the differences in vertical vs. horizontal separation needed to achieve certain levels of isolation. As I remember it, 15 ft. of vertical isolation was equivalent to about 1000 ft. of horizontal. In other words, horizontal is not practical at all.

25+ Years ago, Motorola offered a low power Systel repeater that was just 2 watts, and was designed to offer repeater service combined with telephone interconnect for small warehouses, retirement homes, and factories. Inside the box, it was just 2 GP300 portables, a controller, and cooling fans. They worked, but they didn't last. Most got replaced within 5 years with a "real" repeater. I'll repeat what was said above. A duplexer saves you time, trouble, and money. If you're going to use a split antenna system, you're still going to need cavity filters to make it work properly. Unless you've already got the 2 antennas, the double lengths of coax, and the cavity filters, you're spending more money just to "save" on a duplexer. A properly tuned duplexer "eats" less than 2dB for a UHF system with a 5 MHz split. If you've been paying attention here, you should know that transmit power out is not the limiting factor in most repeater systems. People chase transmit power because they think it's what makes a repeater better. Balance is what makes a repeater system better. Duplexers provide balance.

You ask good questions. Those tiny little flatpack duplexers are designed to "notch" out a single frequency pair (receiver side notches out the transmit frequency, and the transmit side notches out the receive freq). What you have to get your head around is that when those notch duplexers are measured for isolation, they're only getting 55 or 60 dB of isolation. That means that some of the transmit power is always going to be leaking into the receiver - causing desense. When you've got a low enough power setting, the residual amount leaking into the receiver is small, and doesn't cause much trouble - at least, not enough to make a difference when your low power repeater still covers a mile or two, even with just a little bit of desense. The problems begin when you start trying to crank up the power, or even (gasp) toss on a BTech power amplifier to get 50 watts feeding into that flat notch duplexer. Now your tiny little bit of leakage is suddenly drowning out the receiver and causing you all sorts of trouble. Yeah, now you can transmit out to 7 or 8 miles, but you can't even talk back in with your portable until you are within a 1/2 mile. You're also right on the idea of mixing for nearby transmitters. Close channel spacing creates a nightmare of intermod products. The basic formula for figuring out intermod is 2* A +/- B, A being the first frequency, B being the 2nd frequency. Remember, if you've got a small flatpack notch duplexer, and you were tweaking and tuning it tight just to notch out one specific frequency pair and get 65 dB of isolation, and now you're finding out that you need to notch out an entire range of frequencies. That is is why serious duplexers use bandpass cavities, and cost thousands, not hundreds. They also boast isolation figures of 80 dB or better. Gaining 20dB of isolation is Huge with a capital H. Probably better to head over to repeater-builder.com and read up on their duplexer section. They've got it all written up already. They'll even toss in the math if you want to geek out on it.

It's even simpler. Just start up the software - and in the top level menu items - select "view" choices should be something like basic / expert. Select expert. Now you see all the options for rear accessory connector & CWID. The built in Help files in the CPS are worthwhile - even if they are somewhat cryptic.

Those were Helium crypto miners - aka Helium Hotspots for an IoT LoRaWAN network. It's been talked through all over the web in the past week or two. Helium.com for details. If you missed it, people were making $1500-$3500 per month from off-grid mountaintop sites that overlooked major cities. Those same sites now mine about $25 per month since the crypto crash. If someone was putting up those sites in the past few months, they've lost their butt - especially considering the cost of the equipment they've lost, or the fines they might incur.

Putting a 40 watt amplifier on a low budget radio with suspect spec's is the equivalent of putting a 200 HP Nitrous shot kit on your Pinto. Until your repeater has a decent receiver with good sensitivity and selectivity you haven't done anything to improve the performance of the system. No matter how much horsepower you think you just gained.

You would think that's where the pause code would go - but it's not. That's really like a "pause code table" setting. You need to go into another DTMF tab to assign the pause code to that table. I don't have the VX2200 software in front of me, or have a codeplug with the DTMF tables already set up to share, but the built in software Help files will get him where he needs to be.

You can usually set up a pause to happen by setting up a prefix of "#" or "*" in front of the digits. Then you simply insert it into the desired "dial code" string like: #123 - which will create a pause prior to spitting out 123. If you don't have enough of a pause, you can try: ##123 If you look in the Help file, it will give you some settings to get into for assigning a pause character, and the timing. Trial and error is how I usually figure this stuff out.

The Vertex Help file will clear up some of your questions (but probably still leave you with half, and also add another 10 questions.) The 100 msec is the duration of the individual tones. Setting it to a shorter duration will allow your radio to spit out a longer DTMF string more quickly. I've never found machines to have much of a problem with decoding tones - as long as the radio was sending a tone on frequency and had decent deviation - and the receiver had a matching bandwidth & deviation expectations. Usually when I've seen an issue with DTMF going through a repeater, it was that the DTMF tone was being spit out too soon, and a pause prior to the DTMF being sent would help. I have not ever messed around with using DTMF codes on a repeater for user control. My use was for Interconnect dialing and also irrigation control. When everything went narrowband, we definitely had some setup issues related to deviation and bandwidth, but once those waters calmed down and everyone was using 100% narrowband, the stuff became pretty much plug and play. I'm assuming that you do hear the tones going out from your radio when you ket the PTT? I see you have the DTMF sidetone set to monitor. Does there appear to be any pause when you press the PTT before the DTMF is going out? How many digits long is the DTMF sequence?

The GR500 wall mount did not include a speaker. You could add one by tapping into the rear connector. I haven't studied the manual in about 15 years, but there might even be handset audio available at the front mic jack. Good info on pinouts and manuals should be available on batlabs and/or repeater-builder.com One word of advice, do NOT run that unit at high power if you want it to live. The GR series of repeaters were sold as having a 50% duty cycle at high power. It was more like a 5% duty cycle. Fresh cool air helps, but it helps more if you can live with the idea of running at 20-25 watts. Even at the lower power settings, they're still not 100% duty cycle.

I don't disagree with your overall point, but that part made me laugh. The FCC makes mistakes all the time, and then repeats many of their mistakes. I'm not really in favor of dual band, dual certification type radios for GMRS - but I will say that having a $35 "license" with no testing required (other than testing your ability to pay $35) doesn't really create anything except a revenue stream. There's not even a short little quiz to prove that you understand a thing about the rules before you pay your $35. I won't even get into the whole "licensed relative" thing.

Was the repeater receiver ever working better than it is right now? Or, has it always been a little deaf since you've had it? Adding a pre-amp won't fix a failed radio, but it might help to overcome some loss in the receive system. Generally, an MC2000 has a really hot front end (receiver) that wouldn't need a pre-amp. If you're not receiving well, then I'd look 10 other places first before I'd settle on adding a pre-amp as the solution. Do you have a way to measure sensitivity? What's the amount of signal needed to break squelch? Is it the same before the duplexer as it is after? How much de-sense can you measure? What type of duplexer cables are you using?

I just program the Monitor button for "sticky monitor" and that way if I want to hear open squelch, I can temporarily disable squelch. There's rarely any reason for me to want to listen on an open frequency 24/7 - especially if some other user has CWID or MDC on the channel. Private Line may not create any kind of privacy, but it does create peace and quiet for the non-radio geeks in my family. Or, if you've got a mobile, you can just program the radio to go into Monitor mode the moment you go off-hook. Hang up the mic = PL enabled. Pretty simple. Not sure if there's a PL enable function on any radio once you set a channel to CSQ for receive.

Try to remove or de-activate all other channels besides the single active repeater channel. Make sure you're not scanning. Set repeater hang time to zero. You can also try to change to a "split PL" - using different PL/DPL codes for Transmit & receive. That should tell you if there's something internally generated on the transmit side that's keeping the repeater keyed. Without a service monitor and some RF specific test equipment, you're limited to basic troubleshooting methods. Try to eliminate potential trouble points one by one until you get it done.

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.