Lscott

I wouldn’t assume a 100% duty cycle. Those cheap Chinese Duplexers were primarily designed for mobile applications, I believe, which are low duty cycle.

If a young person wants brain dead communication the. by all means use their cell phone. If they want a technical challenge then Ham Radio is where it’s at. Even a Tech class license you can get worldwide communications using various digital modes. Set up an internet connected repeater for digital and maintain it. Then there is satellite communications to test skill level, moon bounce etc.

That’s good! I like to see more young people getting interested in it. Most of the swaps I go to look like a retirement community get together.

Just a wild thought. What is the power and duty cycle rating of the duplexer?

Just another idea.

That’s been my understanding as well.

The FCC do have commercial radio telephone licenses, but that’s not part of the Amateur Service.

There is nothing that prevents anyone from purchasing a cheaper analog only radio if they are happy with that mode of operation. I think one of the concerns with digital has to do with the band being run over by an influx of digital users. That was one of the reasons the use of channels 8-14 was suggested. For typical GMRS operations those are rather useless channels. By restricting digital to just those, by design of the radio (firmware), the rule would be enforceable. That leaves the rest open to those who only want analog FM. I'm not concerned about what effect it might have on FRS. After all they have the same exact simplex channel access that licensed GMRS users enjoy. That means if they don't like the digital stuff on 8-14 then pick another simplex channel to use. Don't forget they are also limited to narrow band and 0.5 watts on those channels as well. They aren't anymore useful to FRS users than they are for GMRS users. Both are stuck with with the same limitations. IMHO if FRS users want access to digital then pay for a GMRS license, buy a compatible radio and quit complaining. Right now they are using the spectrum for free. Anyway the point I was making in that paper was trying to crack open the door to digital voice operation on GMRS that would at least have a good chance of coexisting with FM users while not pushing the FCC into doing a lot of work. The less screwing around they have to do with the rules the more likely they might go for the idea.

DMR has some attractive features. 1. Being a TDMA, time division multiple access, mode the transmitter is only working half the time. For a handheld radio that works out to a significant increase in operating time on a battery pack. That's a huge consideration for those who want the radio to last all day while out hiking the tails. 2. DMR, along with other digital voice modes, provide clear noiseless audio out to near the limit of the range typical of an analog only radio. Where the analog radio starts breaking up and getting very difficult to copy the digital signal is still clear. 3. With the proper radios that can auto negotiate the slot timing among themselves, that's the main caveat, you get two voice paths on a single channel. 4. Finally there are radios that can operate in SFR mode, single frequency repeater, without the duplexer requirement typically necessary for an analog repeater. The SFR, as the name suggests, allows the equivalent of a full duplex analog repeater but using ONLY one frequency, no offsets required. The trick is allowing the use of ANY digital voice mode on GMRS. Some of the objections voiced by several other posters are legitimate. I would suggest you look at this post and read the attached file that goes into the issues a bit more. It's meant as nothing more than to get some ideas out there. https://forums.mygmrs.com/topic/5720-new-repeater-channels-for-gmrs-in-2024/page/2/#comment-57605

That solid sheet metal ground plane will be a HUGE wind load at highway speeds. I can just picture it ripping off the roof rack rail. It was ok for a static test but you need something else. The following link is a suggestion. If you’re using an NMO mount then you need to look for a kit like the one in the link using that mount type. https://www.amazon.com/WORKMAN-WIL-KIT-W-ELEMENT-MOBILE-GROUND/dp/B01D3ITZ9C

You just might be unlucky to be in an area with low activity. You can try scanning all the channels using narrow band. That would make the radio compatible with FRS radios. Usually the FRS radios are frequently employed by hotels and other small business since they don't require a license and they are cheap. See if you can get any activity that way.

A lot of people seem to be attracted to those "Ghost" antennas due to their small size. IMHO I've never been impressed with their performance. Some may have had better luck with them. I picked one up at a Ham swap a while back since it was cheap to test out. The results weren't that good. If someone wants a small antenna I would just go with a simple 1/4 wave type, easy one is a magnet mount. It's only going to be about 6 to 7 inches tall anyway. These have a WIDE bandwidth so when trimmed right could be usable over the Ham 70cm band and the GMRS band too. At the frequencies used by GMRS the ground plane required is only about 6 inches in radius around the antenna base for uniform coverage. The magnet mount achieves the connection to the ground plane through the base using capacitive coupling. You don't need a solid connection. Antenna Scan Results (Stealth Dual Band VHF).pdf Antenna Scan Results (Stealth Dual Band UHF).pdf

Here's a list of common business itinerant frequencies. Common Itinerant and Business.pdf

Due to the crazy Canadian wildfires the Detroit area has one of the nations highest (worst) AQI, air quality indexes, the last day or so at 299! https://www.accuweather.com/en/us/detroit/48226/air-quality-index/348755 That got me thinking about using a mask to filter out the smoke particles and still use a two way radio. They make some systems to use with some types of masks. https://www.mirasafety.com/blogs/news/communications-earpiece-gas-mask-comms Anyone ever use something like this?

Many of the switching power supplies use simple capacitive input filters. When switched on the high inrush current to charge them up can pop fuses and circuit breakers. The better power supplies have a “soft start” circuit that slowly charges the input filter capacitors over a few seconds. If your power supply has a soft-start circuit it might not be working.

There are a few digital voice repeaters on 2M, but nowhere near the number on 70cm. You can discover that easy enough by simply doing a search for one or more digital voice modes on "repeaterbook.com". There is far more spectrum on UHF for various modes that is in short supply on VHF. I also started a thread on this forum some time back on the same issue. The general consensus was UHF is where most of the digital voice mode activity is found.

Digital voice modes are mostly on UHF, the 70cm band too.

There was a line of heavy T-storms that moved through Michigan early last night. I was out in Oxford Mi visiting so tried to get one of the stations for the latest updates. Reception sucked, couldn't pickup crap on any of the usual frequencies, and that was with a commercial grade HT VHF radio too, not some POS CCR one. The ability is nice to have but it doesn't work at times, likely when you really need it.

Some radios I had luck hex editing the code plug to put in frequencies the software ordinarily wouldn’t allow. I had a buddy gifted me 3 two channel Kenwood ProTalk radios he had kicking around his shop ready for the trash bin. They were worthless for Ham use since there was no way to enter non approved frequencies into them there the radio buttons or programming software he could find http://www.vincentcom.com/pdf/KENWOODPDF/TK-3200.pdf Those you can only select from a list of hard coded frequencies in the programming software or in the radios firmware. Of course none of them were in the ham band or GMRS. After a bit of digging around with a hex editor I was able to put in the local GMRS wide area coverage repeater on one memory slot and the GMRS simplex travel channel on the other memory slot directly in the code plug. Now at least they’re useful for something. Other radios one might can hack the code plug to put them on frequencies they weren’t originally intended to use.

Or at least don’t publicly admit to doing so.

I’ve read where people mounted a small tower/mast on a trailer then ran the coax into the house. Technically the antenna is used on a vehicle so it isn’t covered under an HOA. Others put one on their car/SUV/truck and ran the cable inside. Same idea.

The deviation for 11M FM CB I believe is 2KHz. The closest match would be narrow band FM at 2.5KHz.

You'll have to shop around a bit. Don't get in a rush to buy one. A second alternative is the TK-3173. It's the same radio but with trunking features, which you won't care about for GMRS. It's programmed using the same software and cable as the TK-3170. http://www.swscomm.com/kenwood/TK-3173.pdf Oh, before I forget the radios are Part 95 certified to so they are perfectly legal to use on GMRS. Also make sure you get a US market code model. They are several different types out there. I got two from Ireland a while back that required a different version of the software to program them. Look at the photos and VERIFY it has an FCC ID of "ALH34713110". Sellers frequently get the description wrong so looking at the FCC ID is a good way to be sure what you're looking at is what you want. If you get either one I have all the documentation, brochures - user manuals - service manuals, for them. I also have the programming software and the most current radio firmware too. While the official frequency range is 450MHz to 490MHz you can program in frequencies under 450MHz for use on the Ham 70cm band if you have a license or thinking about getting one. The software will generate a warning every time you do that but will accept the entry when you click OK. I have a number of Ham 70cm repeaters programmed in mine and it does work. One of the reasons I like Kenwood radios. Some other manufactures won't let you do this. TK-3170 Grant.pdf