Lscott

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.

To clarify you can't do cross band repeat on Part 95. It's done all the time on Part 97, particularly between the Ham 2M and 70cm bands. I think that's what the OP was trying to convey. It's true you can't do direct cross communications between the two licensed services. Technically there is a way to do it using the right unmodified radios. However the way it could be done would violate rules that say Hams can ONLY communicate with other stations licensed in the armature service, and except for brief one way transmissions for testing for example, one way transmissions are prohibited. I'm not advocating people do this but as a purely theatrical exercise it could be done as follows. Many Ham HT's can do split band operations, TX on one frequency while RX on another in the same band much like repeater operations. In this case the TX frequency would be one in the legal section of the Ham 70cm band while the RX is set to one of the official GMRS channel frequencies. Thus the Ham would be TX'ing on a legal Ham 70cm frequency while ONLY RX'ing on a legal GMRS channel frequency. Using the right GMRS radio that allows programming of out of band RX ONLY frequencies for monitoring and a priority RX function would be used. The GMRS radio would be programed to TX on the legal GMRS frequency the Ham HT is programed to RX on. The GMRS radio would have it's priority RX programed for the legal Ham's HT's TX frequency. The GMRS radio would then constantly monitor the priority RX frequency. Both radios are now TX'ing on their respective legal frequencies while RX'ing on the others TX frequency effecting cross service communications with unmodified radios.

I don’t know how common the practice is now but I have heard about police officers using modified Ham HT’s for communications on frequencies they are not licensed to use. Apparently it was done to hide questionable activities from being monitored or recorded by the dispatch office. Other times it was used by detectives or surveillance teams to hide communications from possible monitoring by criminals. The frequency agility didn’t restrict them to the few official frequencies programmed into their departments issued radios. Personally I did witness two uniformed police officers sitting at a table in a restaurant with an obvious Ham HT, I recognized the make and model, sitting in full view. Both officers had their official Motorola radios strapped to their belts and turned on. I’ll admit one of them might have been a Ham but it just didn’t look right.

Anyway getting back to the topic of this thread about call signs. I wish radios in general had a way to program in your call sign and have it transmitted per the FCC rules. This would be purely for convenience of the operator and a feature that could be enabled/disabled as desired. I've looked at the various builtin tone signaling options in the various commercial radios I have collected. The goal was to get a Morse Code transmission of a call sign with some "creative" setup of the signaling options. The only tone signaling options seem to be 2-tone, 5-tone and DTMF on my radios. There are also options for a PTT ID on Key-Up or Key-Off too. So far I don't see a way to do it. I think using your call sign encourages others to act responsibly on the air. If one can justify not using it then its not a stretch to justify ignoring other rules. To see where that leads a simple monitoring tour of the spectrum between 26.965 MHz to 27.405 MHz AM should prove educational.

If they have a "grandfathered" license then yes it's legal. Otherwise no. A local mall near me is using repeater channel 16, and yes they do have a repeater. The repeater is used by the mall's house keeping staff only. After some research I found they use to have a license but it's expired, has been since October of 2015! As far as I can tell it's never been renewed. I assume the FCC knows about it but just doesn't care. The only reason why I went to the trouble of finding out is the local GMRS repeater, which is only about 6 to 8 miles away, uses the same repeater channel, just a different PL tone. At times I can hear interference from the mall's repeater. I go to the mall frequently just to walk around and I have my HT with me monitoring the mall security and several of the local store's comm's. I don't use a PL tone on any of them so I can hear all the traffic. When I hear some of the GMRS uses complain about some "weird" issue with the repeater it was when the mall's house keeping keyed up their radios. Apparently they use a tone on RX and can't hear other traffic, plus they are not using the Busy Channel Lockout feature that's on just about every commercial radio out there. They have no idea there is anybody else using the frequency. Fortunately they are seldom on the radio.

I can do that, however they are not Part 95 certified. Seems like the FCC isn't too interested in busting people using good quality Part 90 equipment, but that isn't a sure thing. A lot of people are doing so without issues. Both of the radios I have are dual mode, analog and digital. Since digital is not allowed on GMRS I could use the analog half of the radios, which can do wide and narrow band FM BTW. There is only ONE repeater I've seen in the general Detroit area that's list as supporting NXDN in the RepeaterBook database last time I looked. These are the two radios I have that do NXDN. https://comms.kenwood.com/common/pdf/download/05_nx240v_340u_K_1117_typeD%20added.pdf https://comms.kenwood.com/common/pdf/download/10_NX-720HG&820HGBrochure.pdf Spending over $100 on a P25 radio is a bit outside my price range at the moment. The few P25 models I looked that seemed interesting were well north of the $100 mark. One of the other things is getting the software. All the stuff I have was freely downloaded. I think Kenwood has gotten more anal about their radio software for the newer stuff. I heard about dongles and such being necessary etc., however I haven't looked into that much. I think so far I have between 8 to 10 different packages installed to program the collection of radios I already have, and that's just for the commercial stuff.

Unless the Chinese market some really cheap P25 radios the price of the commercial ones is rather high, not something I would look at buying just for hobby use. There seems to be plenty of interest in DMR. Some decently performing Chinese DMR radios are available for a reasonable price. There is a good amount of activity on the HAM bands using DMR. I don’t expect the FCC to allow DMR on GMRS anytime soon. So far NXDN hasn’t generated much interest. I understand there is some fair level of NXDN use in Florida. My self I picked up a used Kenwood NX-340U from eBay real cheap. I was also gifted a used Kenwood mobile radio, NX-820HG. Both are the “-K2” models operating from 400 MHz to 470 MHz. So far I haven’t really did anything with them.

While that is true one thing you can do with DMR, and not with NXDN, is setup a SRF, Single Frequency Repeater, that doesn’t require an expensive set of tuned cavity filters. Several DMR radios have the functionality already builtin. This is due to DMR being TDMA verses NXDN’s FDMA mode.

Based on the good comments on the forum I ordered one myself from Bluemax49er for a Kenwood NX-820GH mobile radio I was given. I might have found one cheaper but I feel confident this will work without issues. Too many super cheap Chinese cables using the counterfeit Prolific chip that don't work out there.

If in fact the noise is coming from the car stereo it's likely radiating from the wires between the speaker output and the speakers. Many new car stereos use Class D power amplifiers. To make it simple its a switching type circuit operating at high frequency, HUGE noise generators if not filtered. If the filtering is insufficient on the amp's output you can try putting your clamp on ferrites on the speaker wires right at the point where they exit the amplifier. You might even have to shield those wires and ground the shield right at the stereo. https://www.analogictips.com/class-d-amplifiers-for-high-efficiency-switched-mode-sound/ The communications between the head unit and the main body is also likely using a fast serial communication protocol. One common protocol used extensively in automotive settings is the CAN bus. Those signals may also be a source of noise radiation and might need those clamp on ferrites too. https://en.wikipedia.org/wiki/CAN_bus

Great! Let us know how it goes when you get all the bits put together and the radio programmed. The narrow bandwidth and low power FRS channels are 8 to 14 at 0.5 watts. Channels 1 to 7 are 5 watts max and wideband, while the repeater main channels 15 to 22 are wideband and 50 watts max. I just added another Kenwood TK-3170 and my first TK-3180 to my HT “collection”. I spend to much time on eBay and can’t pass up a good deal. 8-/ The programming software for the TK-3180 complained about several features that may not work right because the firmware was too old. After contacting Kenwood support they were nice enough to supply me with the most recent version. Didn’t even fuss about it. I might have to buy yet again another different programming cable myself. I have a buddy who got his hands on a used Kenwood NX-820HG-K2 and mic from his work place they were going to dump. He has no interest in digital radios, it also does analog, so he said I could have it if I wanted. Now I need the cable. It’s not part 95 certified however. https://comms.kenwood.com/common/pdf/download/10_NX-720HG&820HGBrochure.pdf

The FCC certification grant is located here for the TK-880. https://apps.fcc.gov/oetcf/eas/reports/Eas731GrantForm.cfm?mode=COPY&RequestTimeout=500&application_id=9wLBCa2uBguLpUibGdVsCA%3D%3D&fcc_id=ALH24593210

If you're looking for the TK-880H brochure with the basic radio spec's look here. https://www.ameradio.com/doc/Kenwood_TK-780%28H%29.pdf

Many business use FRS radios that now share the same exact frequencies for simplex as GMRS. It’s legal for them to use FRS for business purposes. What you are most likely hearing are FRS radios.

Yup, the same attitude that permeated CB back in the 70's. FCC required a license but most users said screw it, or if they had one didn't ID as required. After a huge increase in the number of CB radio users the FCC gave up enforcing the license use and ID requirements, then changed the rules to make the illegal behavior legal. That way they washed their hands of having to deal with it. Hopefully GMRS doesn't follow the same path.