Lscott

Right now only in Oregon State, otherwise you have to keep it in the original shipping plastic bag it came in when using it. 8-)

Glad you had success getting the out of band frequencies to work on your Motorola radios. The Kenwood software works about the same. If you enter a frequency outside the of the official range you get a warning message that pops up. If you click to dismiss it the software will accept the entry. It gets tedious when you have a lot of them to enter, but at least it works. I suggested to a fellow Ham to build a test code plug for a radio he wanted to push petty far out of the official range. Put in frequencies, starting at the boundary of the official range edge, about every 1 MHz apart in successive memories. Then try each one out to see where the radio’s PLL fails to lock, you get a warning tone out of the radio in that case. No guarantee the same range works on another radio of the same model due to component tolerances. Once you know the limits the next question is power output and sensitivity as you mentioned. That depends on the power amplifier’s output filter band pass characteristics, and the RX section’s filter. On some radios the power amp filters can be “tweaked” a bit provided the components used have adjustments. The RX section maybe. Many of the Kenwood radios I’ve looked at use some type of electronically tuned band pass filters. Those I doubt are easy, if at all, possible to tweak. The tuning voltage is likely non linear with the precise value generated by the radio’s micro using an internal formula or look up table.

The important point is paying attention to the amp rating of the fuse. Too low and the fuse will fail. If the fuse is rated close to the max current the radio will draw the heat buildup will eventually fail the fuse. Remember that a fuse is a thermal device, an element has to melt to open the circuit. Fuses operating at elevated temperatures may also fail at current levels below their rating. The voltage rating on the fuse is the max system voltage where the fuse is guaranteed to clear the fault without excessive arcing. Using a higher voltage rated fuse should not be an issue.

Did anybody consider trying the Kenwood TK-3360, or the older model TK-3160 radios? They have about the same feature set as the basic VX-261 units. https://www.motorolasolutions.com/content/dam/msi/docs/EA_Collaterals/ENGLISH/commercial/portables/vx260_series_spec_sheet_ea.pdf The Kenwood radios will do wide and narrow band FM, use various battery pack types including Lithium Ion, plus all you need is a cheap Baofeng type cable to program them. In fact many of the cheap Chinese radio accessories, like speaker mics, work on the Kenwood radios. The software I found on line to down load fairly easy. The VHF models work nice as MURS radios, make sure the power is set to low, with enough channels left over for NOAA weather monitoring. https://www.kenwood.com/usa/Support/pdf/TK-2360_3360.pdf http://astralcommunications.com/site/wp-content/uploads/2013/01/TK-2160_3160.pdf I see the UHF version radios selling on eBay frequently in various states of condition, some are the full package, radio charger, battery pack and antenna. As I've mention before Kenwood radios will program outside of the stated band split. So if necessary even a few Ham 70cm frequencies can be used.

I don't know about Vertex or Motorola radios how the frequency range is verified, but with Kenwood I do. Maybe Vertex or Motorola radios are similar. The radio programming software reads the code plug which has the radio's model number and sub type embedded in it. When the software tries to write the code plug to the radio it first queries the radio for model and sub-type. If the two don't match the software generates an error message. One version of the software with the license key I used for installation even offered to let me change the "market code" changing a radio from a European or Asian model to a US type! The service manual claimed if you used the wrong model type, and the associated market code, to program the radio "the first time" it can't be changed later. Apparently that's not true if you have the right software. Some of the Kenwood radios use "XOR" encryption on the code plug contents I discovered, for example the popular TK-3170 and TK-3173 radios. After some lucky guesses and looking I found where in the code plug the encryption key is stored. It seems to be located in the same place even between totally different radio models. I suspect the software programmers used the same code plug file structure for the beginning section across model types. The key however can vary from code plug to code plug even for the same model type. After decrypting the code plug the version of the radio software, radio model type and the installation license key, used to install the software which created the code plug, was found. The frequency was stored in little Endian integer BCD format. For example 462.67500 MHz was stored as 00 75 26 46, two BCD digits packed into each byte. Any passwords set in the radio, such as power up enable, radio read or radio over write are also stored in the code plug. Without the engineer's license key for example even if you loaded the code plug in to the programming software the radio over write password is blanked out with asterisks. If you know where to look in the decrypted code plug even that password is in the clear and can be recovered allowing a radio to be reprogrammed. The software will prompt the user for the password if one is used and will refuse to either read the radio or over write the current code plug depending on which passwords are set. The channel names, group names, strings in general, are stored in normal ASCII format. Other options and features are likely stored as bit fields or some other type packed data structure. Since none of this will ever be documented by the manufacture so a good deal of experimenting has to be done to reverse engineer the code plug further.

I would like to see the results just to satisfy my curiosity.

Yup, that's the deal. It's really your choice. Most likely the radio's you'll find being sold are the -K type, Part 95 certified, anyway.

That's true. If you don't mind forgoing the Part 95 certification the other band split will work just fine plus gives you full access to the complete Ham 70cm band. I found the other band split I can program my radios down to around 440MHz which covers a lot of the simplex frequencies and the repeater section of the band just fine. Most of the radios you find are the -K type. The programming software you need is the KPG-89D, which I have since it's the same software used on the TK-3180 hand held radio I have. The version I found, V1.61, has the so-called "engineer's" key allowing the bypass of any passwords set in the radio and access to a few more features the usual dealer or end user version doesn't allow. The software installs and works fine on Windows 10 as well. You just need to find a programming cable. Some people here have a good recommendation on where to find one.

One of the first things I do when thinking about buying a radio I'm not familuar with is go look for any manufacture's brochures. They are a good source listing the radio's main features. For the TK-8180 look here. http://www.swscomm.com/kenwood/TK-7180_8180.pdf This seems like a very nice radio.

It would be of interest to see just how much attenuation you actually get. Normally the filter is tuned to get as deep a notch as possible. These cheap Chinese notch duplexers are only spec'ed for 70db or a bit more. The wider the bandwidth the less notch depth you get. Some of the more expensive band-pass band-reject filters have attenuation levels of 90db or more at 50 watts for example. At 5 watts you "might" get away with it in a quite RF area whereas using the same filter with a higher power transmitter may not work. Remember one of the notch filters is used to keep any side bands, phase noise, generated by the transmitter from getting in to the receiver section. In fact knowledgeable people building repeaters stay away from particular models of radios because the transmitter section generates too much crap the filters can't eliminate.

I have a number of commercial Kenwood hand held radios and one mobile. While it did take a bit of searching on the Internet I have managed to find the programming software on line to download. So far I have the OEM software to program the following UHF Kenwood radios. TK-370G TK-3160 TK-3360 TK-3140 TK-3170 TK-3173 TK-3180 TK-D340U NX-340U NX-820HG (mobile) One of the nice things about the commercial radios, at least Kenwood with Motorola not so much, is the ability to program in frequencies outside of the official band split specifications. That allows using the radio for both GMRS and Ham Radio's 70cm band, both TX and RX operation, for those that are dual licensed. The purposed built GMRS specific radios typically don't allow this and could be a factor is which radio you select. Many of my radios have GMRS simplex and repeaters programed along with a bunch of Ham 70cm simplex and repeaters too. Just have to remember which call-sign to use depending on the memory channel in use. 8-) The main problem with using free software like Chirp are some of the radio's features are not supported, or what support there is happens to be buggy. Waiting for Chirp bugs to get fixed, well some never do seem to get fixed. The developer for the module for that particular radio lost interest, doesn't have the time or doesn't have access to a radio to reverse engineer the communications protocol and code plug. Some of the developers are "loaned" radios to use for a period of time then have to return them to the owner(s). If you want to make sure you have full access to a radio's operational features there is no substitute for the manufacture's software, and this is VERY particularly true for commercial radios.

These radios don't seem to offer anything much different that some of the Kenwood commercial radios. You can look for the TK-3360's analog only or the TK-D340U analog/DMR. https://www.kenwood.com/usa/Support/pdf/TK-2360_3360.pdf https://comms.kenwood.com/common/pdf/download/DMR_TK-D240V_D340U_K_letter_1124.pdf You can find the TK-3360's, and the slightly older TK-3160's, on ebay for decent prices. https://www.urci.com/downloads/kenwood/kenwood_tk_2160_3160_brochure.pdf I just recently picked up a used TK-3360 for $30 including shipping, used battery pack and no antenna. There are good deals out there, just have to be patient and look for them.

I would be interested in knowing how deep the notches are for the duplexer. The typical cheap Chinese ones they use are spec'd for around 70db and that's at a very narrow bandwidth. To get a 500KHz bandwidth I suspect the notch depth is rather poor, traded off notch depth for bandwidth, leading to poor performance, i.e poor off frequency rejection and RX desense from the TX side. My understanding is the TX side of the notch filter should be tuned for the exact RX frequency for maximum notch depth while the RX side of the filter should be tuned for maximum notch depth at the TX frequency.

I admit I have one of those. The radio hardware is ok. The programming software sucks. I’m tired of the bugs. They fix something then the next version it’s buggered up again, or something else is now broke. I haven’t touched mine in over 6 months.

I don't know about Motorola but some of the Kenwood radios the code plug is encrypted too. I found out it's a simple XOR type encryption using a key byte stored in the code plug. For the several radio models where the code plugs are encrypted that key was always stored in the same place. Using a hex editor to load the code plugs and the data manipulation tools I was able to decrypt the code plugs easily. Maybe Motorola does some similar.

You have any links to information on this? I find it hard to believe this can happen unless who ever tweaked the radio down some how botched the internal settings. The power brick spec sheets I've looked at show a bias pin that controls the power output. I a few of the Kenwood HT designs there is a feedback loop that measures the current through a set of low resistance resistors. The voltage developed goes into the feedback loop to adjust the bias pin voltage to keep the power output on the module constant. At least that's how it looks to me in the service manuals. Some of the power modules are static sensitive and you can blow them if you're not careful. There is also a warning about getting the pins too hot while soldering which can also bugger up the module.

A cheap Baofeng is not a good choice for a SHTF radio. They're OK for a cheap "beater radio" so when it breaks it's so cheap you won't cry over it. The main reason you see so many people suggest them is because of one thing, they're dirt cheap. You buy a $25 radio you get a $25 radio reliability and performance. I purchased a cheap BTECH tri-band hand held radio a while back. Dropped it on the hard floor at a sports bar while out with some friends, the speaker quit working. Oh well, it was a CCR. What you really want is a radio with a heavy duty case that you could drop on concrete and not have it die, drop in the water and not short-out the innards etc. In a SHTF situation you don't know where you'll be and under what conditions, but the radio must still work, hot, cold, driving rain, dusty or smoky air, mud coated etc.

Yeah, the two handhelds I got for $50 or less each. The sellers likely thought they were simple basic analog only radios. Couldn't pass up the opportunity for the price. When the price is much above the $50 to $60 mark it gets really hard to pull out the credit card or click that "Buy Now" button. Not all the radio I've purchased have worked. I have a hand full that sort of work or not at all. Some I might be able to fix, otherwise they just get picked over for parts. Surprising how expensive buying replacement knobs and other crap like that is when you check out the factory recommended part suppliers. As far as battery packs and antennas go, I consider them consumable items. Out of the huge pile of used battery packs from a while of buying used radios maybe 30 to 40 percent meet the minimum accepted spec of 80 percent of new capacity to qualify as usable. Antennas you can buy aftermarket packs of 5 to 10 for as little as 1 to 2 bucks each. Antennas get busted because people grab the radio by the antenna, convenient handhold when yanking it off the belt or out of the pocket, or the top side knobs. That's why so many used hand held radios are missing the knobs too.

I guess that depends on your definition of "Made in the USA". Many products are the combined result of design and manufacturing teams around the world. A radio maybe designed in the USA, the firmware software programming team located in India with the final product assembled in Asia someplace. For example Kenwood is a Japanese company but all my radios show they were manufactured in Singapore. Then you have US companies, that for whatever reason, can't or won't spend resources on designing a cheap low end product. One example that comes to mind was HP (Agilent - Keysight) sold a low cost digital scope with their name on it. One person looked at the firmware update they got for it and found the name "Rigol" embedded in it. That company by the way makes a series of test equipment and is Chinese. https://www.rigolna.com/ With companies contracting out design and manufacturing then re-badging the equipment you need a score card to keep track of who did what and where. An example of that is a company called "BearCom" which sells a radio model "BC130", but supposedly manufactured by Motorola as the "Mag One" but in a very slightly different looking case. https://bearcom.com/media/wysiwyg/page/bc1301.pdf https://www.buytwowayradios.com/downloads/dl/file/id/1119/product/4224/mag_one_motorola_bpr40_product_sheet.pdf However when you look at the FCC ids for the radios you find they are exactly the same, AZ489FT4873. When you look at the sample name plate required by the FCC to be affixed to the radio you find the name "Yanapa" with some other model number listed. The country of manufacture is shown as Korea. Again you find the same FCC id at the top left of the name tag. https://fccid.io/AZ489FT4873/Label/ID-LABEL-504621.pdf Confusing isn't it?

I wouldn't mind getting a P25 radio just to experiment with but the used ones I've looked at are way too expensive. I lucked out with the two 32 channel digital Kenwoods I have, TK-D340U (analog/DMR) and the NX-340U (analog/NXDN) relativity cheap. Both off eBay and look in almost new condition. I guess the sellers didn't really know what they were selling since they typically sold for 3 to 4 times what I paid. https://comms.kenwood.com/common/pdf/download/DMR_TK-D240V_D340U_K_letter_1124.pdf https://comms.kenwood.com/common/pdf/download/05_nx240v_340u_K_1117_typeD%20added.pdf I was also gifted a used Kenwood NX-820HG mobile with power cable and microphone, the 400 MHz to 470 MHz band split model. The buddy that gave me the radio is a Ham but said he has no interest in digital modes. https://comms.kenwood.com/common/pdf/download/10_NX-720HG&820HGBrochure.pdf

One way to verify the band split is look for the FCC ID number on the radio. Then go to this site to look up the FCC grant. https://fccid.io/ The FCC grant will show the frequency range the radio was tested for, bandwidth and power output. For the popular Kenwood TK-3170 as an example check here. https://fccid.io/ALH34713110 I find fairly frequently that some eBay sellers either get the description wrong by accident, and sometimes it's deliberate, so the only sure fire way or knowing exactly what you're buying is checking that FCC ID number. Second if possible would be to look for the manufactures sales brochure for the radio. Normally you'll find the various band split versions listed and their major part number and minor sub part number identifying the band split. Again using the Kenwood TK-3170 as an example. https://www.wirelessvoicedata.com/downloads/kenwood/kenwood-tk-2170-3170-brochure.pdf One more thing some eBay sellers try to sell non-US radio models. Those can be a big problem since they lack any kind of FCC certification and the programming software could be very hard to find. Personally I had this happen with one of my TK-2140 VHF radios. Fortunately I was able to find the special KPG-74D(M2) version needed to program it. The code plug was NOT interchangeable with the US model, the internal electronics was a bit different, thus I need to maintain two separate code plugs. The radio works fine, just a pain since I now have an odd ball in my collection. As a final note some of the used radios MAY be password locked, which prevents you from either reading the current contents of the radio, and if the write password is set, and you don't know it, you now have a brick since you won't be able to over write the code plug already in the radio. I've had that happen twice now. Fortunately I have found a way to get the relevant software to install with the so-called engineers key that allows bypassing the passwords. Newer versions of the Kenwood radio programming software have these features locked out without some software hacking or "creative" installation methods. If you do end up with a radio like this and can't unlock it you can of course send it to your local factory service center, pay a ridiculous minimum fee for the tech to spend 30 seconds using their "special" engineering mode radio programming software, to clear it for you.

For Ham Radio specific portables, no. However if you look at various LMR, land mobile radios, many used ones have both part 90 and part 95 FCC certification. The radios don’t need part 97 certification for Ham Radio use. I’ve had good luck with the following Kenwood portables: TK-370G TK-3170 TK-3173 TK-3140 TK-3180 The programming software wasn’t too hard to find online. While the radios are normally rated down to 450MHz they can be programed lower into the Ham 70cm band. The software will generate a warning for the out of band frequency but accepts it anyway. The radios should work down to about 440MHz which covers most of the simplex frequencies and all of the repeater frequencies. I also have a collection of Kenwood 16 and 32 channel radios that are part 90 certified so not strictly legal for GMRS. TK-3160 TK-3360 TK-D340U (analog/DMR) NX-340U (analog/NXDN) All of the radios can be programmed for normal or narrow band FM on a per channel basis.

When people can buy a set of bubble-pack radios for $19.95 to $29.95 they won’t bother paying a license fee. The whole farce where the manufacturers and the FCC assumed people would get a GMRS license to operate the dual use radios sold at the time was a failure. They made the non-compliance problem go away by changing the rules so the former non-compliant radios are now classified as FRS and no personal license required. Be careful what you wish for. Canadian GMRS is license free, no repeater access and limited to 5 watts on the same channels used here in the US except on 8-14. Effectively it’s a bit higher power version of our FRS service. The FCC could do that just to make the nuisance of doing the paperwork go away. The repeater owners would get a royal screwing. Remember the FCC is going to take the path of least resistance, administrative work. They did that with the Amateur Radio Service when they reduced the license classes to just 3.

Well if you don’t mind experimenting with another Chinese radio take a look at the TYT TH-350. It’s a tri-band radio and they can be had for $70. Not that much more expensive that the typical Baofeng type. The radio will work out of band, however you have to know the “secret” keyboard option and passcode to change the default frequency limits. And yes I have one in my HT collection. It seems to perform well without the annoying bleed through from close by transmitters on adjacent frequencies. https://www.buytwowayradios.com/tyt-th-350.html The thing with this radio is the back light uses a white LED and it’s EXTREMELY BRIGHT. You could use it as a flash light. In the dark it could ruin your night vision temporarily. Some might find the bright back light an advantage.

Keep in mind this repeater can only operate on ONE of the GMRS repeater channels at a time This is due to the notch duplexer. It can ONLY be tuned for one TX and one TX frequency at a time. If you need to change the repeater channel the notch duplexer must be retuned. That requires equipment most people don’t have or a trip to the local commercial radio shop.