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I think this is what saves us here that use LMR radios on GMRS. Plus also why the FCC hasn't made a fuss over people using such radios on GMRS. I would say the majority of repeaters used on GMRS are repurposed Part 90 equipment. FCC isn't making a fuss over those either. This is likely, my guess, why the FCC hasn't specifically authorized Part 90 radios on GMRS, it is basically implied in Part 95.335(a). Before the 2017 rule changes it was legal, and possible, for a business to get a GMRS license and operate. So, it made sense for manufactures at the time to get certification for both Parts 90 and 95. It was a sizable market. Now, post 2017 rule changes, only grandfathered business, no new applications, can operate on GMRS. The manufactures just don't bother anymore getting dual certification, just Part 90, since that's where the business market is at. I have some radios that in fact are dual certified for Parts 90 and 95. However I have a bunch that are Part 90 only. This is reassuring it's they're very likely legal to use. Given the above I wouldn't hesitate recommending a Part 90 radio in place of the specifically manufactured GMRS radios to new GMRS users. While most LMR, Part 90, radios can't be front panel programmed like the specifically manufactured GMRS radios, some can. This is one such example. https://forums.mygmrs.com/gallery/image/290-nx-1300duk5/?context=new NX-1300 FPP.pdf

A quick google shows a handful of instances of interference if you're sitting right on 433 (either the TPMS light on the dash coming on when you transmit, or occasional noise when receiving. At least 1 seems to have fixed it by moving the antenna. https://kq4afy.xyz/blog/2022/12/tpms-uhf-interference/ https://www.reddit.com/r/amateurradio/comments/1l732o2/today_i_learned/

Thanks for the quick responses.

Yes, they’re allowed. We share portions of the 70 cm amateur allocation with other users, including TPMS.

Short answer: yes. I don't know what brand you're looking at, but the OEM giant in this space is Continental and: https://fccid.io/KR5TIS-09DL

I was looking for TPMS sensors for my trailer. I found the following on Amazon with good reviews: RV TPMS Sensors Something in the product description caught my attention; the sensors transmit at 433.92MHz, which is in the 70cm amateur band. That raises a couple of questions. First, does the FCC allow for these low-powered short-range devices to operate in the 70cm band? I assume that given the fact they last 6 months of run-time on a set of CR2032 batteries, and obviously couldn't have much of an antenna, that they are very short range and unlikely to cause interference at more than 150 feet. Does the FCC allow them to operate in an Amateur band? Second, will they cause interference to me; if I'm monitoring repeaters within the 70cm band, typically a little higher up in the band, would these interfere? I suppose to answer that question one would have to test. The ARRL band plan shows: 433.00-435.00 Auxiliary/repeater links ...so if these are well behaved they would not interfere with reception of a repeater itself, since they are usually in the 442-445 and 447-450 range. And the only way to be sure these are well behaved is to test with a spectrum analyzer or SDR. As an example, though, I've found that one of the USBC-to-HDMI dongles I use at my home office causes interference in the 440MHz range when I'm within about 30 feet of it -- enough interference with enough tertiary spikes that some of the 70cm band is unmonitorable to me when I'm too close to this adapter.

Thanks.

It does not say that it is permitted. It says if there were exceptions, they would be listed, and they aren't. Insults from people like you are meaningless to me.

My license was granted on 2025-07-22 and has no mention of Line A or any frequency restrictions.

Watch this:

I'm sure any of those will be nicer to use than my old boat anchors.

Obviously, it appears that you are not a SME on these types of matters or can demonstrated any professional expertise in the analysis and writing of legislative bills, statutes, policies, rules, regulations, ordinances, guidelines, and enforcing such rules, etc. in a government bureaucratic or legal form. My question still is, after the rule says it is permitted, where does it say that the operation of Part 90 radios are restricted or prohibited?

Mirror Mount like truckers, 1/2 wave

duplicate...the forum wigged out

Theoretically? Sure. In practice? I'd be surprised if it was more than a fractional difference all the way at the edge of the performance envelope.

The length of cable needed to get from the tow vehicle to a good spot on the trailer will probably introduce more loss than just using the antenna on the tow vehicle, with the (almost standard) 13' RG58 type coax that comes with most mag mounts.

That janky cable is usually built into the trailer, and to a connector built into the tow hitch, with a breakaway connection should stuff go wrong. Not something you're stringing across the bed of a truck to a trailer. I guess you can test the failure load of the SO-239 connector on the back of your radio if things ever go really wrong lol

Probably the same as one of the several known features on other 5RMs. Just because the radio can do something, like scrambling and frequency hopping, doesn't make it legal to use. Stick to the basics - we don't need a lot of these new features being added to radios.

It's exciting. Almost like getting to the prize in a box of Cracker Jacks. I can't wait to find out what it is.

There aren't any exceptions specified in GMRS Subpart E for LMR/Part 90. The things you list do not authorize other services; they are just limitations on GMRS. The examples given are references for 2 selected services, not all services in Part 95, that's why it's e.g. There's nothing I can do to make anyone understand what the wording means - you either get it right or you don't.

Those "certain exceptions" are the power levels, bandwidth, allocated frequencies, frequency accuracy and stability, and emission types as listed in each Subpart for applicable frequency being operated. Those rules/regulations are the certain exceptions. In other words, you can operate your Part 90 type-accepted radios on 462.5625 MHz with certain exceptions. Those certain exceptions are: if you do not posses a GMRS license, you are regulated to narrowband emissions and at 2 watts ERP pursuant to Part 95, Subpart B; and if you do posses a GMRS license than you may use either narrowband or wideband emissions and not exceed 5 watts ERP pursuant to Part 95, Subpart E. And if you operate on 154.600 MHz, you will be regulated to the aforementioned exceptions in Part 95, Subpart J. There, those are your "certain exceptions" Yes, there are references to Rules 95.735 & 95.1735 in Part 95.335(a) however, they are only references, and not the context of the subject rule, did you notice the "e.g."? Do you know what the "e.g." means when used? Part 95.1735 was an old rule that more than likely existed prior to the 2017 rewritten/reorganization of Part 95 rules. Obviously, the reference of 95.1735 has been overlooked in 95.335(a) in the editing process since it no longer exist. You said, there are "No Exceptions". Where does it say "No Exceptions", it says under certain exceptions and those certain exceptions are stated in each subpart in respect to the frequency being used pursuant to the respective subpart.

The older GM-30.

You already have a janky cable connecting the lights and likely brakes to the trailer. I don't see how one more cable would make a difference.

Peter Pan. Wife is Tinkerbell

My thought was it removes a great big blind spot.