Lscott

In an emergency don't count on any repeaters to be functioning. Some may have provisions for emergency power, many don't. The ones that do will likely be reserved for emergency traffic only, not open for general communications. For the later you'll need to rely on simplex or put up you own repeater and then insure it has power to continue operation in a grid down situation.

That prevents everyone from accidentally stunning each other's radio. As you pointed out you likely just want the main base/dispatch radio to stun any of the radios in the fleet. I just looked at the NX-300 CPS to see exactly how it's done for that radio. You send the stun command by MDC1200 along with the target radio's ID, the one you want to stun, which has to match. That's the validation part. If the ID's don't match nothing happens. In any case you need a list of each radio and their ID. Of course each radio must have a unique ID for this to work down to a particular single radio. I guess I wasn't clear in the other post about the stun code being different in each radio. In the specific example above it's the radio's ID that has to be different. For the several common digital modes, P25 - DMR - NXDN, each radio can have an individual ID associated with it, at least they should have. The individual ID is used normally for making direct radio one-to-one calls so others don't get bothered by messages not for them. So usually this is already likely setup for a business environment. This also might be very handy for a SHTF situation where for COM-SEC you might not want everyone on your radio net to hear a message. For example maybe you have a stash of food and weapons but only trust a few in your group with the location when out and about but your whole party needs to be on the radio net.

Not true about the certification part. For example the NX-300's are Part 95A certified and will do both analog FM and NXDN digital. You just have to make sure you DON'T use the digital half on GMRS. https://apps.fcc.gov/oetcf/tcb/reports/Tcb731GrantForm.cfm?mode=COPY&RequestTimeout=500&tcb_code=&application_id=66LWdun0EB3LOHyqkdhtQg%3D%3D&fcc_id=ALH378500 https://www.ameradio.com/doc/Kenwood_NX-200_NX-300_brochure.pdf

Oh, one other item. Some of the commercial digital radios will accept remote commands to do things. For example turn on the remote radio's transmitter so the base can monitor what is going on or send the current GPS info for those radios with that feature.

Provided you enable that feature in the radios. Also the stun code has to be set differently for each radio in the fleet. If you set them all to the same code and send the stun command you just killed all your radios that were turned on, on frequency and in range. Oops. Don't forget to keep a record of which radio has which stun code in it.

Yes. There are some caveats. As a few others pointed out be careful with the batteries. Read the guide lines at this link. https://www.faa.gov/hazmat/packsafe/resources/media/Airline_passengers_and_batteries.pdf Now if you want to operate your radio onboard you need to request permission from the airline(s) prior to boarding. Usually by email or snall mail. I also believe you will need the captains permission as well. I have a buddy do this a few times and the above is in general what he did. I don't have the specifics so you're going to have to make some inquiries. http://www.arrl.org/news/view/passengers-now-must-be-able-to-power-up-some-electronics-during-tsa-screenings

They look a little bit like the cheap CLS analog series radios. I have a buddy that picked up a CLS-1110 and CLS-1410 on eBay some time back. You can't do much with them due to the frequencies are preprogrammed, and you can only pick from the list. I guess if you're miles from nowhere nobody will notice you're on the commercial UHF frequencies in them. https://www.hq98.com/content/Motorola-CLS-1110-1410-Brochure.pdf

You're likely right about that. I haven't written much code in a while. I do mostly power electronics design. From time to time I do get involved with some embedded microcontroller stuff.

That's true. Besides if I ratted them out and the FCC shut them down I would have one less thing to amuse me while monitoring. More to the point they're not on their repeater hardly at all. Only occasionally. Since they share the same repeater channel at the legitimate one, which has a tad over 100 people who have requested access so far, there is some interference. I've been at the mall walking around monitoring the security frequency, house keeping and several of the stores. A few times a conversation was in progress on the legal GMRS repeater when one of the house keeping staff keyed up and jammed the legal GMRS repeater. Apparently the house keeping staff has a tone set for both TX and RX on their radios, which is not the same as the other repeater, and the BCL, busy channel lockout which apparently is not programmed into their radios either. They have no idea that the frequency is in use and just use the PTT and start talking. I heard the guys on the legal GMRS repeater complain about some transient audio issue thinking it was the repeater screwing up. No, it was being inadvertently jammed by the mall's repeater.

What you're referring to is a "bulkhead" connector. It's basically a hard shell version of coax cable with threads on the outside. I would NOT recommend them for GMRS. There is a good engineering reason why they should not be used, and likely not on high VHF either. The connectors are NOT designed for 50 ohm impedance to match the coax cable. This results in an impedance "bump" in the transmission line. The longer the bulkhead connector, up to a point, the worse the problem will like become. The problem will appear as an elevated SWR as measured at the radio. The exact impedance depends on the dimensions of the OD of the inner conductor, the ID of the shell and the dialectic material used. When the impedance is not 50 ohms the bulkhead connector with cause an impedance transformation from one end to the other. The exact transformation is dependent on the impedance of the bulkhead connector and the impedance connected on the end. If these are known the SWR could be calculated. Also being a transmission line the SWR variation will repeat every 1/2 wavelength. The worst are odd multiples of a quarter wavelength. Theoretically a half wavelength should cause no transformation. When talking about "wavelength" this is the "electrical" wavelength, not the physical length which will always be significantly shorter due to the fact the RF propagates much slower in the bulkhead connector thus the RF "sees" a longer length. You will normally see this accounted for by a specification called the "velocity factor", typically much less than 1.0 which is what it would be in empty space. The same thing happens with coax cable too.

That's what I figured. I have the tone. Tested it and it works. And yes I had exactly the same though too.

The first problem was positively identifying the source of the transmissions. I was hearing them on the same channel as a local GMRS repeater I use. I heard references to cleaning, food court etc. With all of the local strip malls, hotels and more within a few miles, many using FRS radios I couldn't ID them. Then one day I heard a reference to a hand cleaning station, then a few seconds later I heard the mall security on the same frequency then on their own frequency. That nailed it. I had the call sign for the mall security frequency. Next stop was the FCC database. I looked up the call sign for the mall's security. Got the FRN number. I was lucky the mall security frequency was registered to the mall and not the mall security company, which is an outside service. Then did a search for ALL licenses under that FRN for the mall. 0002748242 https://en.wikipedia.org/wiki/Lakeside_Mall I guessed the house cleaning would be registered to the mall. Bingo, there it was. KAB1523 https://wireless2.fcc.gov/UlsApp/UlsSearch/license.jsp?licKey=194751 Under the "Admin" tab scroll down to the section "Special Conditions". The exact frequencies are listed there, the pair for the GMRS repeater channel 16, which is where I heard them.

I monitor it frequently but almost never hear anything. With only 5 channels you get a few more ding-dongs running telemetry and the available channels are all gone. That user might even be grandfathered in and thus has priority use. You might figure that out by looking up the license info on the FCC database, you hear the CW ID, that's where you start your search. Just because you hear the CW ID doesn't mean the license is active. The shopping mall by me, for example, the house cleaning staff uses GMRS channel 16 with a repeater. I found their license info on the FCC database. It expired in 10/2015 and was canceled a couple months later because it was never renewed. They have been using their radios and the repeater illegally for the past almost 7 years. Oh, nobody ID's and neither does the repeater.

I believe some antennas have a DC connection from the radiating element to the shield. Grounding the shield bleeds off static electricity buildup and generates less noise in the signal while protecting the sensitive front end components from failure. You can get huge static voltage build ups even on sunny days just due to a small breeze blowing across the antenna. I read a story about one Ham who got knocked off his roof after touching his un-grounded antenna, no feed line attached, due to the static voltage on it. I also know people who will disconnect the coax from all their radios, sticking the ends in glass jars, when thunder storms are moving in to the area.

There are some solid recommendations for used commercial grade radios if you want to go that route. I have primarily Kenwood radios so I'll confine my comments to them. The ones I have and feel they work good are the TK-370G, TK-3140, TK-3170, TK-3173, TK3212 and the TK-3180. The radios are either 4 or 5 watt radios. There is little difference between a 4 and 5 watt radio range wise. They all can do repeaters, split tones, wide and narrow band FM, high and low power, scan and so on. The one I've been carrying around for a while now is the TK-3170. I just like how it works, it's small enough to fit in a shirt pocket, light with the Lithium Ion battery packs, and uses all the same programming cables, speaker microphones, antennas and other accessories the cheap Chinese radios use, which is the Kenwood dual prong "K type" connector. The TK-3173 is the same radio but includes trunking, which you don't need for GMRS anyway. https://mra-raycom.com/wp-content/uploads/simple-file-list/Specifications/portables/TK-270G-370G-Product-Brochure.pdf http://www.swscomm.com/kenwood/TK-2140_3140.pdf http://www.swscomm.com/kenwood/TK-2170_3170.pdf http://www.swscomm.com/kenwood/TK-3173.pdf http://www.deisradio.com/files/TK-2212-3212 Brochure.pdf https://kenwoodsub.dealerarena.com/ProductPDFs/10/TK-2180&3180Brochure.pdf You can find these for sale on eBay frequently. You'll also probably need a new battery pack, antenna and charger base. If you already have the two prong programming cable you're all set on a few of the above. The TK-3140, TK-3180 use a different type of programming cable. I believe all of the above are Part 95 certified for legal use on GMRS. The software isn't hard to find on line with a bit of searching. Be careful of the exact model "Type" you buy used. These UHF radios come in several different frequency ranges. The Part 95 certified ones are the 450 MHz lower end to 490 MHz to 520 MHz upper end. I have one or more of these specific radios and they all will be great on GMRS. Just one caveat about any commercial radio, they are not front panel programmable. You can set some of the function keys to select things like tones etc. but in general you need to software to do a proper job setting them up. Oh, these radios can be "pushed" down below the official lower frequency limit, down to at least 440 MHz or lower, so they are usable on the repeater section of the Ham 70cm band for dual licensed people. Now you can legally have one radio to use on GMRS and Ham with zero modifications or special software hacks required.

Selling an "add on" software by the manufacture for their own radios? A company has to make a decision, are they primarily a hardware vendor or a software services provider. Some try to do both and end up doing neither well. What is being proposed is the business model used by example Motorola, now Kenwood looks like they too are moving in that direction. You pay for the basic software, then again for each additional feature. You can end up paying on a per unit basis too. Now you have to keep track of which radio(s) have what licensed features enabled and so on. Even the code plugs are directly tied to an individual radio by serial number. You simply can't take a code plug for one and directly load it in to another radio identical hardware wise because the enabled features may be different. If the radio programming software is a for purchase type option, well it had better work and the vendor needs to be quick about fixing bugs. Forget about "feature creep" I want what's there already to "just work", no excuses. One way to kill a great hardware product is crappy to non existent support. I have a low threshold for buggy software and even less for vendor excuses why it's not fixed or have no intention of fixing it, ever. The danger with any third party software are several. One most likely the hardware vendor doesn't document the communication protocol nor the code plug content structure. With CHIRP its all done through lucky guess work, reverse engineering and experimentation. No guarantee that a later hardware version won't break to software. Even worse that a bug in the software won't "brick" your radio. A few have had that unfortunate experience. Second while CHIRP presents a consistent user interface across multiple radios you can loose access to features that are specific to a particular model. In that case you're back to using the hardware vendor's software anyway. Remember CHIRP can only implement what can be reversed engineered, and even then the developer may choose to note it's just experimental so any bugs discovered may never get fixed because they don't have the time, lost interest or just don't have the radio to experiment with any longer. Remember it's free, so what did one expect for zero cost, so there is little motivation for the developer to spend heaps of time on it.

More companies are going that route. For hobbyists it doesn’t make sense. Some are figuring out that the hobbyist is the ticket to future business. For example with microprocessor development systems they cost a fortune in the past. Now you can get really cheap development boards and free IDE’s. The idea is once you get somebody, college or university student, familiar with their hardware and software they go on to recommend it once they begin working in their field because they know the products. I would guess a number of people have recommended radios from the major manufacturers for their work place, or for others personal use, based on their experience using second hand radios purchased for personal use and scamming up the software. Myself I’ve recommended a number of Kenwood radios because I know what they can do and the software wasn’t hard to find. I wouldn’t mind their new radios, the NX-5200, 5300, 5400 series, but their change in software licensing is a complete show stopper for hobby use. So, for those models I wouldn’t even take one for free. The software licensing model Kenwood has moved to is expensive, restrictive and in general doesn’t fit how I use and program my radios. I have several computers I use, at work - home - traveling, and having the software tied to a particular computer with Internet activation is a deal killer. The above isn’t just with radio programming software you find this with just about all the CAD software out there too. I use a number for hobby use and they are 10 to 20 year old versions before the companies moved to the same license scheme above or required hardware dongles.

For just a few radios that will add up. For hobby use I couldn't justify the cost. For a business it's a drop in the bucket. That's Motorola's business model. They don't cater to the single user. For a dealer it's like buying toilet paper. Spread the license fee over 100's or radios and the cost is almost nothing.

OK. I read it. Not as expensive as I thought. What happens after the initial 3 years ends? You still can legally use the software? If not that sort of sucks. I find I need to make changes time to time, either changing the configuration, buttons, menus and so on. The other is keeping up with the changes to the local repeaters. Talk groups changes mainly on DMR. Others the repeaters simply fail and never seem to get back on the air so off hunting for another one to use. Or new one pops up. One is never really done programming their radio. Something always needs tweaking or changed.

What are your out of pocket expenses so far buying software and the license entitlement ID's?

No Bluetooth option for programming with any radio I have. I think the XPR7550's can do it but the XPR6550's and XPR6580's I've got don't support Bluetooth. I got my cable from the frequently mentioned source, BlueMax49ers. The guy is very easy to deal with and the quality of the cables I got was very good. I spent more than buying some no-name one on eBay but his are guaranteed to work. https://bluemax49ers.com/ What was in that "training" video that required you to spend 15 minutes of your time watching? I probably could have produced the video in 30 seconds. If it's wide-band click this. If it's narrow-band click that. Done. I need to get the radios out and play with them a bit. I had to think about how to organized the zones since the radios I have only allow 16 memory channels per zone. I had to set them up a bit differently than any other radio I own that has zone support.

Did you need to re-tune the cavity filters?Somebody else said theirs was tuned rather wide so they could change frequencies without having to mess with the filter tuning. I find it hard to believe it works that good without getting the RX de-sensed because the notch isn't that deep when not tuned narrow enough.

Makes you wonder how they manage to get and keep customers.

I believe they would be initialized to zero by default. One could also set the compiler warnings to ignore it too depending on whose you use.

Things got stupid because there was no accountability or meaningful enforcement action. Years ago I went round and round with a number of people on the “rec.radio.cb” news group. There was a hard core group who had no regard for FCC rules, couldn’t care less who was interfered with etc. Because of the lack of FCC licensing and no real enforcement they felt “entitled” to do whatever they wanted and had no fear of repercussions. A few of them were the most narcissistic people you would have the miss fortune to ever meet.