Lscott

Slightly off topic. Has anybody any experience with Kenwood’s KWD-AE31K optional encryption board? Seems to be a high end one using AES or DES for their different model digital radios. https://csrc.nist.gov/csrc/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp2200.pdf Some of my radios have a cover plate on the rear under the battery pack to install optional feature boards. Some of the boards available are various voice scramblers, trunking etc. I haven’t been lucky enough, so far, to buy a used radio where any option board was installed.

https://radiofreeq.wordpress.com/2013/07/15/3-3-3-radio-plan-for-shtf-communications/

If range was strictly limited by power the range would be reduced by sqareroot(Pout/Pin). So a 40% power loss would amount to a range of 77% of what you would get with zero power loss. For a 20% loss it is approximately 89% range from the zero loss case. https://www.phys.hawaii.edu/~anita/new/papers/militaryHandbook/one-way.PDF As you noted a 20% loss is only 2DB. Even a modest gain antenna would make make up for the loss. Depending on your operating characteristics it might not matter much unless you’re right at the fringe of making contact.

I see posts at times where people want a radio for “emergency” communications. That’s great. But if you don’t have a way to keep the radio on the air it’s useless. Various radio services are used, Ham Radio, MURS and GMRS/FRS. Since this is primarily a GMRS forum what plans and procedures have people implemented, such as frequencies, alternative power sources (solar, generators etc.) to keep their station on the air? Myself I have radios for all of the above. I also have a collection of solar panels, charge controllers and tend to use LiFePO4, LFP, battery packs. I hate Lead Acid batteries. I’ve ruined enough of them even with care. In addition I have a few battery eliminators when using the mobile or the big LFP battery packs. The LFP batteries you can charge and just about forget them on a shelf for a year or more and they still hold enough charge to power a radio for a significant time. Can’t do that with a Lead Acid type. For antennas I have one dual high gain on the Jeep that works for Ham, MURS, GMRS and another dual band I can deploy on a portable 20 foot push-up mast. I have additional mobile antennas with magnet mounts I can use too. Making a 1/4 wave antenna is dead simple. For GMRS the vertical element is only 6 inches tall. Used some 2M elements that screw into the magnet mounts and cut them down to the frequencies required. I did that for a 1.25M one since I have a few tri-band radios for Ham and didn’t have an antenna for the band. Some of the charging bases for my radios use up to 15 VDC, while the battery packs they charge never exceed a bit over 8 VDC. Running them on 12 to 14 VDC should work fine. A few of them I modified with Anderson Power Pole connectors to run off a vehicle electrical system or the LFP packs with the adapters I made. One set of radio models I have battery cases that will take various types of expendable batteries.

Somebody picked up two Motorola XTS-2500’s for a tad over $100. If they have battery packs, chargers, programming cables with software it was a super good deal. I don’t so I bid on the Kenwood radio, have the software, programming cable, battery packs with chargers for it. https://www.ebay.com/itm/2-MOTOROLA-XTS2500-III-UHF-380-470-MHz-P25-Digital-Two-Way-Radio-H46QDH9PW7BN-/165026697807?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=711-127632-2357-0 https://www.ebay.com/itm/2-MOTOROLA-XTS2500-III-UHF-380-470-MHz-P25-Digital-Two-Way-Radio-H46QDH9PW7BN-/165026697807?_trksid=p2349526.m4383.l44720.c10&nordt=true&rt=nc&orig_cvip=true

This is the brochure I found. Go figure. https://www.motorolasolutions.com/content/dam/msi/images/vertex-standard/legacy-products/vx_924_specsheet_en.pdf Looks like they have more than one band split apparently, but the brochures don’t show them.

What do you use the VX-924 for? It has a listed band split of 66 MHz to 88 MHz. Unless you can get it to drop down to cover the 6M band, 50 MHz to 54 MHz I don’t know what else you could do with one in the US. I know the UK has a 4M band around 70 MHz so it would be useable there. There was some talk at one point about a 4M band here as well. Don’t know where that went.

Yup, you’re not alone. The TK-5320 has a used battery pack and charger base, but no antenna which I have plenty of anyway. I think I already have several battery packs that fit this radio I got with some of the other used radios I’ve purchased. The seller guarantees the radio is functional. I paid $110 for it on eBay, cheaper than just about any of the other P25 radios I saw.

I have so far, just for my commercial Kenwood radios, 14 different versions installed. Some the only difference is a different "market code", North American verses European models, that have different versions of the firmware too. Examples, I have the TK-3140K's and the TK-3140M's, different versions of the CPS required. And Even the code plugs are not interchangeable, the radios have different feature sets. Then there are the TK-3170K's and TK-3170E's, same CPS but the code plugs are different, again differences in feature sets. And for the Ham radios from Japanese and Chinese manufactures it's a big collection too. I ended up doing a spread sheet showing which model radios use which CPS to keep things straight for all my radios. Then there are the different battery packs and chargers....

I would like to thank everyone for the help! One thing I found with the programming software was the various settings for ID's talk groups etc. was set to use Hex number entry by default! Dah! I couldn't figure out right away why I couldn't enter some of the settings, my DMR ID has 7 digits, but the software allowed only 6. When I saw a note in the help file about a setting in the "Tools" menu to change the P25 section to use a different number format then I could make the entries. I have no idea if other radios and their software does both decimal and Hex number entries. New radio and a new learning curve. 8-/ Maybe my next radio will be a cheap HT with System Fusion. Right now I have radios for D-Star, DMR, NXDN and now P25 when it shows up. This is the nearest P25 repeater to me at the moment. Not many around MI, OH, IN or ILL. on 70cm. https://www.repeaterbook.com/repeaters/details.php?state_id=26&ID=276 Repeaterbook.com is great for looking up repeaters to use BTW. Also there is a free app for the iPhone at least.

I'm waiting to get my latest radio acquisition, a Kenwood TK-5320. Its a dual mode analog/P25 radio, from an auction at a good price. I got the 400 MHz to 470 MHz band split version, perfect for Ham Radio. https://pdfs.kenwoodproducts.com/18/TK-5220&5320Brochure.pdf I'm in the process of building a code plug for it using the KPG-112D V2.01 software. I have a few questions. 1. Is there any standard P25 simplex frequencies people use for P25? 2. Is a unique ID required to get on a networked P25 repeater? If so where do you get one assigned? I already have my DMR and NXDN ID's. 3. I see that talk groups are used like with DMR. Where are those listed? Are they the same as used for DMR?

Welcome to the forum. Lots of recommendations for HT’s. It all depends on if you want new GMRS specific or used commercial radios with Part 95 certification.

Open Repeater Initiative. https://arkradio.net/open-repeater-initiative/

The Canadians don't have access to the repeater input frequencies, however I haven't found anything that specifically prohibits communications using the common simplex frequencies for cross boarder communications. I could be wrong here. Anybody have any info on this?

As far as I know this isn't legal. Also the Canadian GMRS radios, at least the legal ones, don't have access to the 467 repeater input frequencies anyway.

That’s not really duplex. It’s simplex operation using split frequencies. TX’ing on a 467 frequency and RX’ing on a 462 frequency, well good luck hearing anything since there is no repeater to translate the signal on the 467 frequency down to the 462 frequency you’re listening too. Off course the other radio could be setup to do the reverse, however trying to use more that two radios just won’t work because one of the other radios will be using the wrong TX and RX frequencies in relation to the other two. I’ve thought doing something like split frequency simplex to frustrate jammers, at some point in the past, but to accommodate more that two radios requires a more sophisticated method involving fast scanning radios, PL or digital codes to have any hope of getting it to work.

That’s one place I would sort of suspect to find that kind of activity. Since PMR is right there on the Ham 70cm band with the channels starting at almost the calling frequency of 446 I think it would get noticed. Things like foreign language use, no call signs, kids screaming/babbling and general screwing around on the air would be clues to unlicensed use. Since you mentioned you’re are in the LA area I’ve read recommendations not to take your Ham or FRS radios to Mexico. At least where I’m at here in the Detroit area there is a reciprocal agreement between Canada and the USA so operators from either country can use their radios in the other with certain ID requirements being met. As far as I know cross boarder communications on GMRS is not allowed either between Canada and the USA. Of course there is no issue with Hams doing it on the Ham bands.

I thought getting one would be interesting to play with on the Ham 70cm band. I found two more models from Kenwood in addition to the TK-3701. http://www.walkietalkie.eu/documentos/catalogos/cat-en/Cat_KENWOOD_TK3401D_en.pdf https://bhvtotaal.nl/media/productdownloads/t/k/tk-3601d_brochure.pdf I have a TK-D340U that does analog/DMR (TDMA) and a NX-340U that does analog/NXDN (FDMA). https://comms.kenwood.com/common/pdf/download/DMR_TK-D240V_D340U_K_letter_1124.pdf http://comms.kenwood.com/common/pdf/download/05_nx240v_340u_K_1117_typeD added.pdf Either one of these two radios could be programmed to communicate with a PMR/DPMR radio on the Ham Band. What I’m not sure about is if the FDMA digital mode out of the two apparently different digital PMR modes is compatible with NXDN. Anyway has anybody noticed these PMR radios being used by unlicensed people in the US, likely tourists visiting here?

I was thinking if I could get one really cheap to experiment with it might be fun. I looked on eBay to see what a high quality dual mode analog/digital PMR radio costs. In this case a Kenwood. The only one I found was pretty expensive. https://www.ebay.com/itm/Kenwood-pro-talk-radio-pmr-ProTalk-is-a-tk-3701d-radio-/304087133273?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=724-127637-2357-0 My main point is has anybody stumbled across these radios being used in the US? The European 70cm Ham band runs from 430 to 440 only. Above that are other services. The PMR446 service is the equivalent to our FRS service except they can use digital voice modes. This point should be considered whenever the idea comes up to allow digital on GMRS. The Europeans have shown it can be done and exist along side the analog only FM mode. I’ve read on other forums warnings against US tourists from taking their FRS radios with them while visiting other countries where it isn’t legal. But some do anyway. I assume foreign visitors to the US have done the same with their PMR446 radios. I was questioning if anybody has run across an instance where this happened. And, in that area is it a big problem.

Has anybody any experience with unlicensed use of European PMR446 and/or DPMR446 radios operating on the US Ham 70cm band? I would likely expect this around major international tourist spots like Disney Land etc. Apparently there are 3 different modulation types used depending on radio. Narrow band FM, TDMA (aka DMR), FDMA (similar to NXDN). https://en.wikipedia.org/wiki/PMR446 https://kenwoodcommunications.co.uk/files/file/comms/uk/pmr446/PMR446-White-Paper-V6_18AUG2016_JT_KB.pdf https://www.datamatik.no/media/produkt/tk-3701de.pdf

That’s the way I read it as well.

Read section "A6.2.1 Channel Frequencies:". It specifically states The following 8-channel carrier frequencies are reserved for possible future use as repeater input channels and are not available for simplex communications: Channel Frequency 16467.5500 17 467.5750 18 467.6000 19 467.6250 20 467.6500 21 467.6750 22 467.7000 23 467.7250

I can read very well. Your issue has nothing to do with Part90/95 debate but is about a dual service radios, Part 97/95. The statement stands as I wrote it. To end the debate over the issue you mentioned was getting the FCC's interpretation of the rules. You seem to be intent on proving your point, well back it up with the FCC's point of view. Either they agree with you or they don't. In the later case you may have the opportunity to help pay down the national debt by $10K or so. It's really that simple. At least one other poster did exactly as I suggested to you and contacted the FCC about using Part 90 equipment on a Part 95 only service, at least its on topic. We now know what the FCC thinks about Part 90 equipment being used on GMRS, he included their response in his post, regardless of how one reads the rules.

For tracking there is a very nice FREE tracking package that runs on Windows and Linux systems. http://gpredict.oz9aec.net/

The only people whose interpretation of the rules that matters is the FCC's. To cut out all of the debate have you taken this up with your local FCC field office? If they say you're right then that's end of it. Same if they say you're wrong. The safe play is get the official interpretation of the rule(s) in question straight from them. Perhaps nobody on the forum is right. That would far more to useful to everyone than any raging debate here.