Lscott

I have a subscription to QEX which is their tech publication. The articles are several levels above what you see in QST. When the ARRL sends out a request for funds to cover their efforts on spectrum issues I try to send them a few bucks. It's worth it. I don't think most people understand how many and how often the Ham bands are being targeted by commercial interests. That's how we lost part of the 1.25M band. As it is Ham are SECONDARY users on the 70cm band in the US. In various countries Hams only have 430 MHz to 440 MHz. From Wikipedia: U.S. reallocation In 1973, the FCC considered Docket Number 19759, which was a proposal to establish a Class E Citizen's band service at 224 MHz. The proposal was opposed by the ARRL and after the explosive growth of 27 MHz Citizen's Band usage, the FCC dropped consideration of the docket in 1977.[9] In the late 1980s, United Parcel Service (UPS) began lobbying the FCC to reallocate part of the 1.25-meter band to the Land Mobile Service. UPS had publicized plans to use the band to develop a narrow-bandwidth wireless voice and data network using a mode called ACSSB (amplitude-companded single sideband). UPS's main argument for the reallocation was that amateur use of the band was very sparse and that the public interest would be better served by reallocating part of the band to a service that would put it to good use.[10] In 1988, over the objections of the amateur radio community, the FCC adopted the 220 MHz Allocation Order, which reallocated 220–222 MHz to private and federal government land-mobile use while leaving 222–225 MHz exclusively for amateur use.[citation needed] The reallocation proceeding took so long, however, that UPS eventually pursued other means of meeting its communications needs. UPS entered into agreements with GTE, McCall, Southwestern Bell, and Pac-Tel to use cellular telephone frequencies to build a wireless data network.[citation needed] With the 220–222 MHz band then left unused, the FCC issued parts of the band to other private commercial interests via a lottery in hopes that it would spark development of super-narrowband technologies, which would help them gain acceptance in the marketplace.[citation needed] In the 1990s and into the 2000s paging companies made use of the 1.25-meter band. Most all such use ended by the mid-2000s, with the paging companies being purchased by others and services moved to newer systems, or having gone out of business.[citation needed] Then there was this garbage recently with the 2M band. http://www.arrl.org/news/restraint-urged-in-response-to-2-meter-reallocation-proposal

I'll bet it was interesting.

You can take a look at this one. It’s specifically for GMRS. https://www.arcantenna.com/products/gmrs-mobile-vehicular-antenna-base-loaded-chrome-coil-rugged-no-ground-plane-required-with-spring-rbc-450-5-ns With no ground plane required you can use it just about anywhere. Some of the dual band J-pole like antennas are another possibility for backpacking. Again no ground plane required. These you can hang on a string in a tree or zip tie to a fiberglass pole on your backpack frame. Also being dual band you can use either your GMRS or MURS radio with it. https://www.ebay.com/itm/222236729087

That sort of depends on your definition of hand held. There are people that go hiking or bike riding with a small back pack. In the backpack is a small battery, sometimes a small amp, with an antenna mounted on the backpack frame. The antenna is a no ground plane design. The user just runs a short jumper cable from the radio’s antenna port to the backpack. While this is for Ham radio many of the ideas could be applied to GMRS. https://mqc.beepworld.it/apps/download?f=%2FDOC%2FBiblioteca%2FWA3WSJ_s_PM_Handbook.pdf You might want to do some searching for bicycle mobile too. I’ve seen some very clever setups for using a hand held radio on a bike with a good mobile antenna etc.

Windows has a remote feature, Remote Desktop, where you can login remotely from another computer. At the point it's like sitting at the other computer's keyboard, screen and mouse. The remote computer uses Windows terminal services client. https://support.microsoft.com/en-us/windows/how-to-use-remote-desktop-5fe128d5-8fb1-7a23-3b8a-41e636865e8c I do this all the time at work. I have a Linux VM running on another computer with RDP, Linux's remote desktop service like Windows, and access it remotely over the company's network with Windows terminal services client software.

That's right up there with people building cross-band repeaters between MURS and FRS. Then use a cheap Baofeng to transmit through it since it is a dual band radio. Likely the cross-band repeater was built using Baofengs with cross over cables, cheap duplexer and dual band antenna too.

I got several of the VHF XPR-6550's and the low split UHF versions for Ham and GMRS. No hex editing required. When purchasing these off eBay i check the FCC ID to make sure which band split the radios really are first. Sometimes the seller doesn't know or spec's the wrong one in the description. The thing that is inconvenient is the 16 channel per zone limitation and just one 16 channel scan zone. I had to reorganize how I programed the radios compared to everything else I have to avoid the 16 channel limit. I did discover one thing about the radios hardware wise. The SMA antennas are slightly different from what you commonly see. While my Kenwood antennas, reverse SMA like the Chinese radios, screw into the radios they don't work. Looking at the bottom of the screw connector the official Motorola ones the center pin is flush with the edge of the screw barrel. The Kenwood's are recessed a bit so the center female pin doesn't make contact with the male pin in the radio. I had to buy some Motorola specific antennas and checked the connector on the bottom in the photos to be sure they would work before paying.

I’ve been doing some research looking into some very rarely used digital voice modes. One that has my interest peaked is dPMR. So far it seems it’s an European thing. It’s very closely related to NXDN, uses the same RT modulation, the the CAI, common air interface, is different. I don’t see any mention of it being used in the US commercially or by amateurs. https://en.wikipedia.org/wiki/Digital_private_mobile_radio https://kenwoodcommunications.co.uk/files/file/comms/uk/pmr446/PMR446-White-Paper-V6_18AUG2016_JT_KB.pdf Apparently at least one model series of Kenwood radios can be modified to use it. See link to brochure, first page in the middle on the right side. I’m not sure if it’s limited to just the”E” versions or not. https://www.azqartelecom.az/pdf/p1_3_1.pdf The software to enable it I discovered is KPG-97FW. The few European radio dealers I’ve contacted haven’t replied and Kenwood support in the US hasn’t been helpful on this topic either. I’ve only found one site that has it, Russian of course, but you either have to pay them a bunch of money for access to their collection of radio software, it’s very extensive, or contribute stuff they don’t already have, which isn’t much. So does anybody have any experience with dPMR and the above software/hardware?

My real first GMRS radio was a Kenwood TK-370G. The current grab-n-go radio is the Kenwood TK-3170. It’s small, light weight, uses Lithium Ion battery packs. I just haven’t had the desire to drag my more expensive analog/digital radios out. Some have FCC Part 95 certification. Until some digital mode is officially blessed by the FCC they’re likely not going to see much of any use except on the Ham bands.

I picked up a TH-8600 mobile a few years back new for about $100 on sale. I was looking for something super cheap to use in my Jeep. This is the exact problem the radio has. The receiver sucks, I pick up a city fire dispatch station which is about 10 to 15 miles away on several UHF channels I have programmed for GMRS/FRS! The only good thing about it is the case is built like a tank, but that's not what I got it for. You get what you pay for, and maybe not even that in some cases with these CCR's. https://www.tyt888.com/?mod=product_show&id=39

If you’re open to buying used commercial radios there are some very goods ones to pick from. My favorite portable is the TK-3170. It will likely do everything you want and some that the cheaper Chinese radios can’t. You can buy them for reasonable prices if you shop around. https://pdfs.kenwoodproducts.com/9/TK-2170&3170Brochure.pdf

I've been trying to track down info on how to convert a Kenwood NX radio form NXDN to dPMR. I got a very brief message from Kenwood tech support the radio has to be sent in to have the "enhanced" feature function activated besides any firmware/protocol updates could be done. I would rather try it myself. There is a brochure for the NX-220E/320E which says it can be done. The "E" versions are for the European area. https://www.kenwood.it/files/catalog/it/Brochure-NX-220E_320E.pdf In the programming software there is a advanced "special" feature check box under the mode section, which I suspect is what Kenwood support was talking about, that doesn't appear unless you have a hacked version of the software or a special install key to unlock a lot of the engineering functions. Anything with that asterisk next to it is a special advanced engineering function. There are bunch of these through various menus with this version I have. I suspect their tech support would simply ignore any requests for help trying to use any of these advanced features since they are intended for dealer/depot use not end users. dPMR is primarily a European thing and is very closely related to NXDN, they use the same modulation type but the protocol is different. I haven't seen much if any mention of it being used here in the US.

Those radios need to "auto tune" feature of a Motorola test set? This is just for my info. The 6550's and 6580's I have need that so you can't manually set some of the RX parameters.

I’ll bet Motorola paid to have their radios “seen” on TV. No real difference than seeing a clear unobstructed view of band names on various products in movies. Just another form of paid advertising.

Oh, one thought did come to mind. If the the radio can be read then compare the code plug that was written to the one read out of the radio. If the chip is buggered up the two should be different. That will likely settle the issue.

If the chip is failing nothing is going to fix it except a replacement. I'm just suspecting that's the problem, a few failing bits, because he said he can program other channels with the same setup and they work.

You might be unlucky to have a memory chip in the radio that has partially failed, a few bad bits in some memory locations. If that's the case don't be surprised if you later notice some other things don't work right.

Protecting "trade secrets" is harder that defending a patent in court. For trade secrets the complainant has to show they followed strict security protocols in regards to who saw the information, how it was tracked and how access was controlled. Non disclosure and non compete agreements are another matter. At least for non compete agreements they have to be reasonably limited in scope, duration and geographic area, to have a chance in standing up to a court challenge. I would start to worry about this country when we start stealing wholesale technology from the Chinese. At the rate things are going I hope that never happens.

You didn’t specify what frequencies you programmed into the radio. There are two frequency spilt versions of this radio. Which one do you have?

I general I have several different sized LFP, Lithium Iron Phosphate, battery packs, solar panels and MPPT charge controllers. Then to connect everything up I have pre-made cables and adapters using Anderson Power poles all stored away. Most of my equipment are handhelds so I keep several battery packs charged up and on standby. The NiMH packs I have to rotate through the chargers somewhat frequently due to their higher self discharge rates. The Lithium Ion type packs can last for months without losing to much of their charge. I also have a few mobile power adapters for the handheld radios. For the higher power mobile type radios I can power them off a large 40AH LFP battery pack. That one using a large Anderson Power Pole adapter. That's wired to a terminal block where I can branch off using the smaller adapters. I keep several 12VDC LED strips, about 3 to 5 watts, around for emergency lights too. The solar panels are typically anywhere from 5 watts, 10 watts, 20 watts, 30 watts and 50 watts each. They're small enough to store easily and setup. The smaller panels are perfect for keeping the handheld radios going. Most of the Kenwood charger bases need 15VDC to work at about 1 amp. For those I have some DC to DC converters that will take 9.8VDC to 36VDC input and provide a regulated 15VDC output at up to 1 amp for the chargers. Perfect for battery operation.

And this is the link for the study for switching to digital on the VHF marine band too. https://docdb.cept.org/download/3503?fbclid=IwAR1tGdhlzA5PkEWEi36JdbN1D5_sRmIQz_FSqLmv9YuR-Cpw_S_59DQc0Pk

Oops. This should have been the link for the TK-3701 radio in the last post. https://www.connect.fi/images/docs/TK-3701D_20192511_LR.pdf

Oh as a side note it seems the ITU is considering going digital for the VHF marine band. On another forum site some are guessing it could come down to a choice between NXDN or dPMR. Both are very closely related. https://csrc.nist.gov/csrc/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp2200.pdf Myself I’ve been looking around for a relatively cheap dPMR radio to add to my collection. The one I would like to get is the TK-3701. It’s only 1/2 watt but would be fun to play with. Just one problem. They’re expensive. https://www.connect.fi/images/docs/TK-3701D_20192511_LR.pdf Supposedly there are cheap Chinese radios that do dPMR but from what I’ve read they use some weird version the AMBE vocoder chip which isn’t compatible with the one used by the standard for dPMR.

https://csrc.nist.gov/csrc/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp2200.pdf

The Kenwood modules will do that. Plus you need a special “key loader” just to access the cryptographic module from what I’ve read.