Lscott

Unfortunately you can't conduct business activities on the Ham 2M band. About range comparisons between MURS and FRS radios in the open I don't expect a huge difference between them. However if one is using external antennas that would be different, but FRS that isn't allowed to use external antennas so the tests would be between MURS and GMRS radios. From a very basic technical view point the typical antenna on a GMRS HT is nearly a quarter wave long, about 6 inches, and the body of the radio is large enough to make a fair ground plane. Compared to a VHF radio around 150 MHZ where a quarter wave antenna is 18 inches long so radio body is a poor ground plane. It's often mentioned the typical 6 to 8 inch rubber duck VHF antennas have a negative 5 to 6 db gain relative to a quarter wave ground plane antenna. Without going through the math using quarter wave ground plane antennas for VHF and UHF the VHF radio has approximately a 9.5 db (a factor or 9) advantage due to "path loss" over a UHF radio. So for a 2 watt MURS radio the range would be equivalent to an 18 watt UHF radio with line-of-sight operation. Now using just the rubber duck antennas the over all gain difference is reduced to around 3 db more or less. In practice you might not even notice it. IMHO this is sort of the way I see it.

Other than the few purposed built radios for MURS what other radios have people used for the service? I'm aware they are likely not Part 95 approved but I assume people use them anyway, like older Part 90 radios. Finding good used Part 90 UHF radios seems fairly easy. The VHF models are harder to come by and generally sellers ask significantly more for them.

Well, in a way they already have with FRS and upped the allowed power to 2 watts on most channels. When you start hearing digital communications pop up and no meaning full enforcement then you know it's headed down hill. By my work place I monitor FRS and several local business frequencies on the cheap BTECH tribander in my office. I did catch some brief DMR traffic on channel 17 or 18 a few times. You know it was DMR due to the rapid pulsing of digital noise you hear. I did bring in my D878UV once and decoded it just to verify it was DMR. No FRS radio can do DMR so it had to be either a commercial grade radio or a Ham rig programmed for FRS/GMRS. No idea who or where in the local area it originated from. I'm expecting to hear more DMR stuff and wait to see if the FCC steps in. I haven't heard it in a while so maybe something happened.

The E-Comm mobile truck my Ham buddy worked on was done on a shoestring budget. Lots of volunteer time was invested in building it. I think some, maybe all, of the radio equipment was sourced by the city it was being built for so they had quality radios. Other E-Comm mobiles are built by and funded by local radio clubs. You figure $200 to $300 a pop for a good used commercial grade single band radio, one that hasn’t been beat almost to death, adds up. When you need to cover several bands and services you can easily end up spending $1K to $2K or more just for basic FM radios. Frequently a collection of HT’s, preprogrammed, are kept in the mobile because you can’t depend on volunteers who show up to have their own when the emergency breaks. Then there is the wiring, coax, connectors, antennas, power supplies, battery packs, chargers, lighting etc. so you have to figure in maintenance costs. Radios fail, antennas break, they need repair or spare back units along with the test gear to keep it all running.

I guess what does it mean by “a lot of money”? A lot of Hams are involved with professional communications and know the difference in performance between a CCR and commercial grade equipment. You give them a $50K budget you’ll get your APX radios. You give them $500 you get Ham swap “specials”. I have a Ham buddy who is involved with commercial communications as a radio tech for a local city’s transportation department. He was one of the volunteers who worked on a mobile communications truck. The truck was an old donated electric utility service one. A ground of volunteers completely refurbished it and built it with little money from the city that wanted it. They had to scrounge around for the best equipment they could find, or donated themselves, with the budget they had to work with. Another buddy just put up a UHF repeater. He spent $300, out of his own pocket, just on a used multi-bay commercial grade high gain antenna. Then add in the cost for the hard line, Kenwood repeater, cavity filters, controls etc. it gets expensive very quick even buying used.

No backup power -> warm beer fridge. ??

There are some real world results which have been documented that one can use to make some educated projections. https://en.wikipedia.org/wiki/Starfish_Prime

One very important point is local service and support. Most of the CCR's if you have an issue you either have to send it all the way back to China or hope the local seller will swap the defective radio for a good one. I went round and round with TYT, by email of course, about a TH-350 tri-band radio. There was no TX audio using the builtin speaker, however an external speaker microphone worked fine. I asked for a service manual for the radio, won't supply one. Asked for at least a circuit section for the audio section with the external mic/speaker ports shown, nope. I was told I could send the radio back for service. I told them I only paid $70 new for it and the cost of shipping would likely equal or exceed what I paid so a return made no sense. They finally sent two internal mic elements and phone jacks free of charge thinking that was the likely problem. I just haven't bother to open up the radio to tinker with it yet. Neither of the parts may fix the problem so a schematic at least would have been the best option and then I could figure what parts if any I need once I identified the issue. So for the time I wasted on emails etc. I just got another one. The funky one I just use with a speaker mic for now. When I get really bored I might take it apart and try swapping out the parts at some point. I also had a BTECH tri-band with audio output distortion problems after dropping it on a cement floor at the local Twin Peaks while out with some work buddies. I'm a bit disappointed that's all it took to mess it up. No external, or internal, visible damage I could see. Lucky for me I just sent it in to BTECH and had it replaced under warranty. With these CCR's if they F-up you can likely count on throwing them in your junk box and buying another one. If that happens too many times one would be money ahead just buying a high quality radio to begin with. Some of the commercial Kenwoods I purchased used look like they were thrown at a brick wall, busted cases. worn out key pads etc., and they still worked, just got an aftermarket rebuild case kit off of eBay.

Have a look at these. https://baofengtech.com/product/amp-u25d/ https://www.miklor.com/COM/Review_DMR-Amps.php

All the Kenwood commercial grade HT’s I have are manufactured in Singapore.

As far as I know P25 phase 2 isn’t really finalized and it’s targeted at trunking systems anyway I believe. I got a clean looking Kenwood TK-5320 UHF P25 phase 1 radio. I found out I can’t access the trunking menus unless I have a “key file”. So far I haven’t had any success getting a copy of the key file software. I got the radio with the 400 to 470 band split primarily for Ham use so the trunking menus are not useful other than to satisfy my curiosity. A buddy just picked up a used XTS-5000 which he wants to use as a scanner for the local public safety frequencies on 800MHz. In his case he found an old DOS program for generating the key file. He seems to have gotten what’s called “non affiliated” scanning working on it. One other bit of software I’ve been on the lookout for it the “key loader” which loads the digital encryption keys into the radios. Seems like both Motorola and Kenwood uses this method. Depending on the radio it’s either an option you need a license for to enable it, or a separate option board that installs in the radio. In the Kenwood case the software uses a serial connection on the multi-pin port to talk directly to the encryption module. The D878’s you just enter the keys into the radio’s CPS and write the code plug to the radio. So, in a SHTF situation these radios are easy to setup for secure communications without extra software or hardware. My understanding is the D878’s use DES256 encryption which I’ve read will work with Motorola’s DES256 but not the simpler basic encryption if that is of any interest to anyone.

I have a couple of the VHF and UHF XPR-6550’s as well. They’re not bad radios. I’m primarily a Kenwood guy. The chief complaint I have is the limit of 16 channels per zone. I do a lot of scanning with my radios so the above is a major pain so at the moment I’m not using them much. I know the 7550’s don’t have the limitations however the funky antenna connector is a deal breaker. That’s why I went for the 6550’s to experiment with. They’re also cheaper when buying used. I also have the XPR6580 to experiment around with on the Ham 33cm band. There is a nice hack using in memory hex editing for CPS-16 to change the lower band limit from 935MHz to 902MHz. Unfortunately there isn’t much 33cm band activity around my area currently.

I’m trying to get a buddy at work to just try for his Tech Class license, he already has his GMRS license. Was also into scanning. He’s interested but seems to get hung up with other commitments to go for a VE test session. I did get him to switch from the CCR he had, UV-5R, to a better radio, a used Kenwood TK-3170. That’s just about all he uses now. My boss said something a while ago about “maybe” getting a couple of radios to stay in contact with his 12 yo son at school. Hasn’t brought up the topic in a while however. I emailed him some info and radio brochures. At the time he said he was looking at a couple of the CCR’s you see on Amazon. He said if his kid wrecks the radio or looses it he’s not out of a lot of money. I guess that’s one point in favor of CCR’s. I think the best option for him is GMRS at the moment. I have another buddy who I got interested in Ham Radio, he was already into scanners and CB. He got his Tech Class license and now is really getting into digital radio. He also just for fun got his GMRS license recently too. He still uses 11m CB with his “export” radio. I’m trying to do my part. All of the people above are younger than I am.

That’s great. I’m encouraged when I see young people at Ham swaps and hear them on the air. It’s NOT just an old farts hobby. We need young people with new ideas.

Not all CCR’s are complete junk. The original model D878UV I have is an alright radio. Is it the equivalent of a higher end Motorola, Kenwood, ICOM etc., no but it gets the job done I wanted it for and didn’t break the bank. The later models I question if the performance and features justify the significantly higher prices, which I don’t think they do. People use to laugh at Japanese electronics, like the current Chinese stuff, but they got better and higher quality. The Chinese radios will likely do the same sooner or later. If you start looking at test equipment designed and manufactured in China you quickly find out it isn’t junk and the higher end stuff is really causing manufacturers like Techtronics and Keysight (spin-off of of the old HP) headaches in the low to mid-tier equipment range.

Nothing. Your right on the money. My point is what can one expect for a $25 radio? You pay $25 you get get a $25 design, if you’re lucky. You also can pay $25 and get something that can’t bear down the street too. There is a reason why they’re so cheap.

You get what you pay for, and sometimes not even that.

Have a look at this site. Has a lot of info on building repeaters. http://www.repeater-builder.com/rbtip/

I found a good deal on a Kenwood TK-5320-K2 on eBay a while back on an auction. Now I'm looking around for the VHF version. It took a lot of looking and waiting to find the UHF radio. https://comms.kenwood.com/common/pdf/download/TK-5220_5320_Specsheet.pdf If you never used the digital half the analog FM half of the radio is really nice. The same can be said for the NX-200 and NX-300. People have been getting the older NX-200 and NX-210 for railroad monitoring, "railfan" activity, since more of the communications is taking place on digital NXDN. I have two of each in my collection. The two NX-300-K2's I sent out, due to low power issues, and had them fixed with alignment done on them. I couldn't just send them to any radio repair shop since they were the "intrinsically safe" models. Only a few Kenwood shops are certified to work on them. https://rcsonline.net/wp-content/uploads/2017/07/NX-200_300.pdf I believe the NX-300-K's have FCC Part 95 certification while the NX-300-K2 don't, if that really matters to anyone. Otherwise they are the same radios but with a different band split. For anybody interested in SHTF situation and wants some measure of security the radios come standard with a basic 15 bit digital scrambler function. Also an add-on digital encryption board can be installed too, expensive, and requires a special "key loader" to write the encryption keys to the radio. I looked at the brochure for the VX-829. If I read it right there are only two band splits available. One looks like it covers the lower part of the UHF band 380 MHz to 450 MHz, and the other higher 450 MHz to 512 MHz spilt. Do the VX-829's allow you to enter out of bounds frequencies? The Kenwood's will do so with a warning window that pops up every time. The Motorola XPR6550's I have won't, period. One has to be very sure to buy the radio with the desired band split. https://www.motorolasolutions.com/content/dam/msi/docs/vertex-standard/legacy-products/vxP820_p25_series_na_en.pdf

I purchased two new Lithium Ion battery packs for some of my Kenwood radios from a regular eBay seller a year or so back. Neither battery pack would charge in the official Kenwood KSC-25 charger base. The LED would just blink red, error condition, and failed to charge. After some investigation I discovered there is an internal wire connection between two of the several charger base contact points inside of the official battery pack which tells the charger base what battery chemistry it's charging. The after market packs didn't have it. I confirmed this by soldering a thin wire external to one of the new battery packs between the two contact points then inserted it in to the charger base. It worked. I contacted the seller and they tried to blame the charger base as being at fault. No, I told them their battery packs are the problem. They sold the battery packs as a "replacement" for the Kenwood battery packs and went so far as to put Kenwood's battery pack part number on the case . I went round and round with them several times before I got eBay to issue me a refund and sent the battery packs back. Later the seller tried to get me to leave good feedback, more like begged. I refused. I told them they more than likely knew about the issue since I wasn't the first to buy them and I'm sure others complained but avoided the bad feedback. I suspect the seller got a batch of these from a battery pack manufacture in China for a cheap price because the missing wire programming connection was a manufacturing defect, and instead of junking them sold them to recoup some of their cost. The seller tried to flip these on eBay to make a few quick bucks. I left bad feed back along with the exact reason why so anyone else reading the reviews hopefully won't get taken, and not having the expertise to figure why they don't work, believing the seller's BS excuse. I then turned around and purchase two more from a US seller, generic battery packs. I had zero issue getting those to work in the official Kenwood charger base. Of course they got very good feedback. The price was about a buck or so more than the defective battery packs I returned.

Yup, and even the expensive used radios aren't any better either from my experience. About 1/3 to 1/4 of the used battery packs that came with all the used radios I've purchased were junk. They either didn't charge, hold a charge or the useful remaining capacity was far below the rating on the case. The usual benchmark is when a battery pack gets down below 80 percent useful capacity, based on the case rating, the battery pack is considered end of life. You have to make a determination if the battery pack is worth messing with. For example a battery pack with just 60 percent of 2000 mAh capacity remaining is 1200 mAh, compare that to a 1450 mAh battery pack with 82.8 percent useful capacity. They both have the same total capacity. In general when buying used radios, where the seller includes a battery pack, don't place much value on it. Battery packs are typically considered "consumable' items and the seller will likely state they make no guarantees about the battery pack condition. You can usually count on having to buy a new battery pack. For the typical Kenwood radios I have they run from $20 to $25 each for the generic ones. If I get a used one that tests out at 80 percent or better I consider myself lucky and got a better deal than I thought. Be careful if a seller states the radio comes with a new battery pack. I paid more for a used TK-3212 because the seller made that claim. The battery pack "looked" new but tested out at around 50 percent. I ended up getting a partial refund from the seller who admitted his claim was based on the physical condition and no real testing. Also buying "new" generic battery packs, typically from China, may not have the claimed capacity either. If you do buy one or more I highly recommend you test them if possible. If you don't have the specific equipment to test a battery pack a rough estimate can be made using a few power resistors connected to the terminals, a cheap digital meter and a stop watch. Divide the nominal battery pack voltage by the resistance in ohms, then multiple by the time to get amp hours, and them by 1000 to get milliamp hours. The lower voltage cut off point to stop testing is dependent on the battery type and where the radio will shut down due to low voltage. Most of my Kenwood radios with shut down at 6VDC.

I don't have the radio but I do have the software installed. I'm going to make a few guess for things to look at and or try. I looked at the "Optional Features" -> "Optional Features 1" menu. What do you have entered for the "Group Name text length"? This Kenwood radio the total text length you can display for this model is 10 characters. Any text for the group name comes out of that total. So, for example, your group name text length is set for 3 then then max text length for channel name is 7. No matter how you set it up the total between the two can't exceed 10 characters this radio. The "Display Character" should be set for "Channel Name". I also noticed in the key assignment panel the "SCN Switch" should be set to "None". You should NOT be using any kind of scrambler for GMRS or FRS. If you somehow got the radio into the scrambler mode the two keys "c" and "d" work as the scrambler code select. That might be another reason for the funny operation.

I just did a quick look at the CPS for the Kenwood TK-3170, analog only. A number of people on the forum use this radio. The stun function is done by sending a series of digits using DTMF tones. If the stun feature is enabled in the target radio then it will react, otherwise it's ignored. Apparently they only way to target a given radio is it must be programed with a unique stun code. The radio has no idea where the codes originates from so you really need to keep the codes secret. I haven't even looked at how the few Motorola XPR radios do it. I suspect it's like you and gman1971 mentioned. What this clearly shows is anybody that has a mixed fleet of radios likely will need at least ONE radio of that manufacture, and likely model type, with the ability to send the stun command out. I think for operational simplicity any radio that is likely to get lost or stolen should be all of the same model and type. Then you don't have to worry in an emergency with fast changing conditions who has what type of radio and then trying to find one to send out the code before any major damage is done. You should have each radio clearly labeled, lets say a unit number, on the case so everyone in your group knows which radio they have so if lost or worse it can be report accurately and quickly.

For my NX-300 the below is right out of the help file. Apparently as long as the radio gets the command in MDC1200 format and the radio's ID matches the one programmed into the radio it works. I see no mention where there is a restriction on what radio can issue the stun command, other than if the MDC code transmit is enabled in a particular radio. You also have to have the right code for the stun command as well. As I mentioned other radios and manufacture's likely implement this feature differently. _______________________________________________________________ Stun Validation Stun Validation allows you to configure whether the transceiver will be in the Stun state by the transceiver receiving a Stun command in the MDC-1200 format. In the case that Stun Validation is enabled in the transceiver, and when the transceiver receives a Stun command and the received ID matches the ID preconfigured for the transceiver, the transceiver will be in the Stun state and cannot be operated. In the case that the transceiver is in the Stun state, and the transceiver receives a Revive command and the received ID matches the ID preconfigured for the transceiver, the Stun state will be aborted and the transceiver can be used. Range: Check (Enable): Enables the capability to disable the transceiver when the transceiver receives a Stun command in the MDC-1200 format and the received ID matches the ID preconfigured for the transceiver. Uncheck (Disable): Disable the capability to disable the transceiver even if the transceiver receives a Revive command in the MDC-1200 format. Default: Unchecked (Disabled) -------------------------------------------------------------------------------------------------------- Stun Code Stun Code allows you to configure the code to disable the transceiver which will remain disabled until the transceiver receives a code to revive (enable) it. Stun Code is intended to prevent an unauthorized person from operating the transceiver, for instance, when the transceiver is stolen. When the transceiver receives the Stun Code, the transceiver transmits the Stun-on Tone. When the transceiver receives the Stun Code followed by "#", the stunned transceiver will revive. Range: 10 digits

I’ll have to dig deeper into this. From the quick read through on the specific radio I looked at there wasn’t anything that restricted the stun command being issued by a radio that stood out. The feature is spread out over several different screens as check boxes and other entries so I could have missed some important details. What you mentioned could be right for the models you have. I’m guessing each manufacturer implements it differently. It’s likely different even between models from the same manufacturer. I think some of the analog only radios I have include it too.