Lscott

I've purchase many used radios on ebay. If you shop carefully you can find some good deals. Just make sure the seller has a return option. I did buy a few radios with no return option, however many sellers are HIGHLY motivated to avoid any negative feedback. In the few cases I got a bum radio, with a no return policy, the seller refunded the full, or nearly so anyway, the purchase price and told me me keep the defective radio. In that case I ended up sending it out for repair, which basically cost about the original purchase price. So, in the end I spent about the same amount of money, but ended up with a fully checked out, repaired and aligned radio.

One of the first commercial radios I purchased was a Kenwood TK-270G. It works fine on MURS. It's not Part 95 certified for it since the radio was certified in 1999, before the MURS service was created. My understating is it should be fine to use, grandfathered in, so long as the power, frequency and bandwidth are set correctly for the 5 channels. https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95/subpart-J/section-95.2705 https://fccid.io/ALH29463110 https://www.manasrekha.com/pdf/TK-270G-370G.pdf

My experience with Kenwood radios is it’s possible to operate the radio outside of its official band split a bit. With the lower official limit of 146 it’s likely you can get it down to 144. I’ve had better luck with the 40 MHz range in the band split than the 70 MHz or higher ones. Where possible I try to get the 400-470 split on UHF. That covers the Ham 70cm band, GMRS and the usual commercial frequencies. This range seems to be more common on the dual FM/digital mode radios. It’s much harder to find in the analog only models On VHF I love my analog only TK-2170’s, those are 136-174 split. Perfect for Ham 2M, MURS, marine, FM railroads and NOAA weather. These are the VHF version of the TH-3170 I typically use for Ham 70cm repeaters and GMRS.

Yes. Then it comes in two frequency splits to make it more interesting. https://two-way.ca/wp-content/uploads/2019/11/TK780-specs.pdf If the goal was to get a 2M radio for ham it might be ok with the right spilt, 136-162, otherwise the seller is the one who got the steal on the deal. I always get the manufacturer’s brochure for any radio I’m interested in to double check the specifications first. A few that looked good initially I just forgot about it once I saw the specifications. The second thing is look up the FCC ID to see what the frequency range is. You can look up the official frequency range on the FCC’s database with the ID. Most sellers show the tags on the radio. If they don’t ask for a photo. A lot of sellers get the description all wrong. If they don’t have the ID’s or photo then forget it. There are some dishonest sellers out there trying to dump basically worthless radios for high prices.

Does anybody know of any use of dPMR, not to be confused with DMR? As a note dPMR has the same on-air modulation as NXDN, but the digital protocol is totally different. There is a “license free version” dDPMR446, but that’s a European thing. I’m looking at the licensed version of dPMR. https://dpmrassociation.org/dPMR-a-brief-overview.html I have some radios with this mode and haven’t found any info on line about Ham activity using it. https://forums.mygmrs.com/gallery/image/500-ic-f3162dt-front-and-back-sidepng/ It doesn’t even appear as a “special” mode to search for even on “RepeaterBook.com” thus my question.

I have the software for the MTX400. Never tried it since I don't own any Midland radios. MXT400_Setup_1.05.zip

Unfortunately manufactures "assume" that GMRS repeaters are using the "usual" 5MHz so that gets baked in to the radio's programming software and or firmware. For the most part it works so it's a fair assumption and simplifies the radio programming. This seems to be the case with the GMRS specific radios being sold. The options to work around that is to to use a radio that can be unlocked so arbitrary frequency splits can be programmed, or use a commercial grade radio. The later option typical requires the radio tech to program in two frequencies, a receive and a transmit, there is no entry for a frequency split, or offset. When I first got into using commercial grade radios years back, and coming from a Ham radio back ground where the radios had entries for the offset, it was a bit of a mental adjustment to get use to the idea. You do have to pay attention to which frequency goes into which column. It's easy to switch the two around and end up transmitting on the output frequency and receiving on the input frequency, oops. This is one of my preferred analog only radios for GMRS. https://forums.mygmrs.com/gallery/image/263-tk-3170jpg/?context=new This is a sample of the programming for a Kenwood TK-3170, which is what I usually carry around for Ham UHF and GMRS use.

You might want to look at something like the antennas in the below link. https://n9taxlabs.com/shop/ols/products/dual-band-murs-gmrs-slim-jim-with-10-or-16-foot-cable No ground plane required. You can try hanging it up on the window.

Oh, that won't be very popular.

Gee, that's might be hard to do. Have two radios and a cold beverage, but only two hands. Got to make a hard choice what to hold on too.

The interesting thing about the rules is it simply states that the repeater input frequencies and output frequencies have to be picked from the allowed list. Note the rules say nothing about any kind of required frequency shift. https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95/subpart-E/section-95.1763 There is no requirements the input and output frequencies must be 5MHz apart. While that is the usual case it's not required. One could really frustrate users of preprogrammed, firmware locked, GMRS radios by selecting a pair of frequencies, from the allowed list for repeaters, that are not using a 5MHz split. Any talk about how that would affect channel sharing is another topic.

Yes, but I read it as only allowed as specifically mentioned in the rules under narrowly defined conditions. I also though I read amateurs are only allowed to communicate with other stations in the amateur service, USA or other countries, as a general rule at one time, but I can't seem to find the exact location where that was in Part 97. I could be miss remembering.

Great! I had picked up a BTECH amp used at a Ham swap for about $50. It was basically new in the box. https://baofengtech.com/product/amp-u25d/ I noticed the power gain drops off outside of the Ham band noticeably from the max of 40 watts. On the GMRS repeater frequencies for 4 watts input I get maybe 20 to 25 watts out. It could be better, but I didn't pay that much for it. I was more interested in something that would handle all of the typical digital modes and FM analog for the various HT's I own. The amp fit the requirements. I've been looking out for a deal on a used VHF version of the amp.

I've seen those for sale. I always wondered if they were any good.

What kind of amp are you using BTW?

These are the Part 97 rules that apply. 97.111 Authorized transmissions. https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-97/subpart-B/section-97.111 97.113 - Prohibited transmissions. https://www.law.cornell.edu/cfr/text/47/97.113 97.115 - Third party communications. https://www.law.cornell.edu/cfr/text/47/97.115

Very nicely built!

https://wd8iel.com/wp-content/uploads/2023/01/Duplexer-Cable-Length-Determination-Procedure.pdf https://www.repeater-builder.com/antenna/w6nbc-duplexer-book/ch9.html

Velocity factor typically unimportant unless you're using line sections for building filter stubs or phased array antenna systems. What the number specifies is how fast the signal propagates along the coax verses in free space, which at a velocity factor of 100 percent would be exactly the speed of light, so at 85 percent the signal is moving at 85 percent the speed of light. https://picwire.com/Resources/Technical/Technical-Articles/Velocity https://www.febo.com/reference/cable_data.html The reason why it's important for phased array antenna systems is the length of the cable has to be calculated so the RF signal arrived at the respective antennas at the exact point in time for the radiated RF waves to add/subtract in space to give the desired signal strength in the preferred direction. https://hamsignal.com/blog/2-element-vertical-phased-array-my-first-attempt

At a press conference on August 12th, 1986, US President Ronald Reagan said, “The nine most terrifying words in the English language are ‘I’m from the government and I’m here to help.’”

The only thing I see that has any chance of changing is allowing the use of Part 90 radios on GMRS. And that's still a VERY BIG if. Allowing the use of Part 90 radios would acknowledge what's been going on for years, and would make the practice legitimate. All those used wide-band only LMR radios would find a new home on GMRS. They would be a better and higher quality alternative to the CCR's out there. The fly on the butter are the radios need programming. Since GMRS was aimed for non technical users how one would placate the FCC's concerns over missed programmed Part 90 radios causing interference to other services has to be addressed. That won't be easy to do.

Have you considered using a VM, virtual machine, to run an older version of Windows? You can try VirtualBox. https://www.virtualbox.org/wiki/Downloads Then for a Windows install try here. https://winworldpc.com/library/operating-systems Win 2000 might be a good pick. If you need something more recent you'll have to poke around and look for a pirate copy. Then an "activator" might be required. VirtualBox works well. I've tried several versions of Linux, which I'm using now to post to the forum, and various versions of Windows, Win 98 up through Win 10 Pro for example. The Linux VM's are used when I'm getting software from questionable sites. The Window VM I use for testing the software. If it come with a "free" virus I just dump the VM and restore my saved clean copy. No big deal. Some software likes to grab the network card MAC address, hard drive serial number etc. as a form of copy protection. If that software is installed on a VM you can copy the VM to a different physical computer and it doesn't know the difference. I have a friend who does that with some expensive programmable logic controller software. He's moved it to several different laptops and it still works just fine.

I think that was very common on 40M. Now I think the band has more or less been "harmonized" to eliminate that mess.

I have a buddy who deliberately setup a cross band repeater, 2M/70cm, since he had the radios and a dual band antenna. Nice thing about it is you don't need an expensive set of tuned cavity filters, just a decent duplexer you can buy for $50-$75. Switching frequency is as simple as changing the channels on the radios, no filters to re-tune. Yup. After a while the mics all start looking the same.

This topic and post isn't as silly as it sounds. Being near the Canadian border it's entirely possible to contact a "foreign" station on GMRS from the US side. So, this is of interest. One can research the topic by going to the Canadian site, their FCC equivalent, and look over the rules. https://ised-isde.canada.ca/site/spectrum-management-telecommunications/en The point about contacting an amateur station using a GMRS radio is very possible, and cross communication can be done without modified equipment on either end. And yes this topic does pop up on this forum occasionally. Most Ham radios can be programmed to operate in split band mode, i.e. transmit on one frequency and receive on another. This would be similar to using a repeater shift. Some can actually do cross band operation, say between 2M and 70cm. The better GMRS radios have the ability to "monitor" a priority frequency while sitting on a valid GMRS channel. Others have a dual watch function, effectively dual receive. The scheme works by programming the radio to transmit on a legal frequency for the licensed service while receiving on the other one. This way neither operator is transmitting out of band, nor using modified equipment. The rules are written such that this kind of operation is prohibited, i.e. cross service communications or what could be considered "one way" transmissions since no reply is expected on the licensed band, the transmission originated from, from the other station.