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They want to ensure if you wind up shipwrecked or overboard, you have zero chance of getting through it unless they provide. Exactly why I will never go on a cruise.

Cruise line publish lists of what is permitted or prohibited. For example Royal Caribbean has these rules regarding ham radio and two way radios: HAM Radios or other transmitting devices are strictly prohibited due to potential interference with the ship's onboard communication systems. This does not include baby monitors, which are permitted. Guests are allowed to have two-way radios, more commonly know as walkie-talkies, for onboard personal communications. Basic specifications are as follows: Up to 10-mile coverage range, Up to 5 watts power, Internal Voice, Operated Transmission, No external mounting antenna. https://www.royalcaribbean.com/faq/questions/prohibited-items-onboard-policy

Interesting read however this article is from over twenty years ago and I can’t help wonder what changes may or may not exist now to the laws there. It’s noteworthy that they now use encryption for police communications and such which has been implemented after this was written.

Yep, same. For $125, I figured it was worth the experiment

In this sort of application, there is something to be said for commercial radios. It was mentioned 'did I just bump the channel knob' and that's a thing if you have one. Personally I would be looking at a CDM750 for this specific application and dealing with the 4 total channels that can be programmed in it. I realize that as you travel track to track and races to race that others might be on the same channel and you might need to move. But 4 channels should actually be enough to have something usable for the event. Of course the high dollar race teams all have a licensed frequency, so they don't tend to have issues with others interfering with their comms. The other thing with a CDM750 or similar radio is the quality of construction. Race cars are not luxury sports sedans with leather and adjustable 'comfort systems'. They beat you and vibrate and generally are a rough ride. I remember the difference in my Camaro just building in the cage and tying the subframes (unibody 2nd gen). Even with the mostly stock suspension system the car suddenly rode more like a log wagon and less like a pony car. And the solid motor mounts didn't help much either. CDM750's are dirt cheap since they are only 4 channels. No one wants them, they all want the CDM1250s and 1550s. I would be interested to hear how that radio holds up in a purpose built race car over time.

Yes, if both radios are programmed correctly, that's how it should it work. The repeater picks up the signal from one HT and retransmits ("repeats") it with more power from a more advantageous position. Typically, a repeater is situated in an elevated position, meaning it can receive and transmit more effectively than a radio at ground level. If there are GMRS repeaters open to public use within range, that would give you the communication capability you want. That's the primary reason I put up a repeater. I have a couple of buddies living to the east of me where I can reach their HTs with a base unit and tall antenna, but not with an HT. The repeater gives us HT-to-HT capability over a wide area. GMRS repeaters are privately owned, and some owners allow public use while others don't. As a general rule, if the repeater is listed in public databases with the CTCSS/DTCS code, it's available for public use. You're not permitted to use a repeater (or simplex, for that matter) on any service for which you do not have the appropriate license. Some repeater owners are pretty casual about the license requirement, while others are strict, but FCC regulations do require that you be licensed for the frequencies you use.

The nearest hospital is a couple of miles away, and it doesn't have an MRI machine. Small town Oklahoma. Would I pick that up despite having a DCS code set? Obviously, there's something that can cause noise on that frequency regardless of the code, but I'm puzzled about what it could be.

I might do that if it goes on for a long time or becomes more frequent. TBH, my primary concern was that my repeater might be causing it. Now that I know it isn't my fault, it's primarily a matter of intellectual curiosity.

That was my first thought. However, in order to be heard on my repeater channel, wouldn't it have to open the squelch? I have a DCS receive code on my HT, but I hear it anyway. Could there be some sort of electronic signal that can be heard despite the DCS code?

Actually, the receive code I'm using is DCS. I typically have one side of my base or mobile radio scanning, and so far, I've only picked it up on 15. Because of how random it is, it's possible I've just missed it, but that seems unlikely. Nevertheless, I'll set a radio to GMRS 1 and see if I pick it up there too. I don't remember if I've heard it when I'm away from the house. I'll try to find out.

Sure, just use the GMRS repeater frequency. And welcome to GMRS!

You cannot use ham repeaters without a ham license, period. You must reprogram the radio to frequencies you are legally licensed to use. Sent from my SM-S911U1 using Tapatalk

I heard that but have been skeptical. Thanks for the documentation. Wow.

Hi everyone, New to world of gmrs. Have a Uv5r+. it came programmed with ~50 nearest ham repeaters. I understand simplex comms, but my question is if a buddy has the exact same radio/programmed the same way, wouldn’t we be able to communicate via one of the local repeaters we are both in range of that’s programmed in our radios? So if he goes 1 mile away and we lose connectivity with one another, shouldn’t we be able to tune into the same local repeater and now communicate? We do not have Ham licenses but do have GMRS. Should we be finding the nearest GMRS repeater and communicating through it? trying to understand the difference. Thank you!

Instead of a receive tone engaged, try setting a receive DCS code in your radio to see if it still receives it. Noise can include several CTCSS RX tones but might not so easily mimic a DCS code. Have you tried listening to other channels that are adjacent to channel 15? Channel 1 is the closest of the GMRS frequencies at 462.5625 MHz. Channel 16 is at 462.575 MHz and then channel 2 is 462.5875 MHz. This might help you see how broad the bandwidth of the noise is. If it’s truly random noise it might be pretty broad, but if it’s a digital signal it should be fairly narrow. A spectrum analyzer like @WRUE951 suggested would be helpful also. Does it still happen away from your house or if your main breaker is open? Try recording the audio for a few seconds and post it to this thread.

Live near a hospital? I got an MRI a couple of years ago, and as I approached the facility and drove away from it, channel 17 was picking up the exact sound I was hearing while inside the MRI tunnel. Otherwise I'd guess DMR or some other digital signal. My SDR is particularly good at letting DMR on nearby frequencies intrude into what it picks up in the GMRS band.

This is what i was going to say, but it does not explain why/how its opening his squelch/getting past the RX tone he has set.

Sounds like you are picking up digital transmissions from nearby source. I.e.: DMR Activity: You might be hearing Digital Mobile Radio (DMR) signals, which sound like a buzz or "machine gun" noise on an analog radio. Other Digital Signals: There are various other digital radio signals that can bleed over or interfere with GMRS frequencies and could be generated from nearby public safety digital radios. I.e police dept. Utility Use: Some digital signals are telemetry data or other utility uses that might be operating on or near GMRS frequencie you might want to invest in a Tiny Spectrum Analyzer which will help you with frequency and pinpoint the source. Lots of you tube videos out there for Tiny Spectrum Analyzer

As an example. One would think in a modern country like the UK monitoring like we do here, basically everything, is legal. Nope. https://www.monitoringtimes.com/html/mtlaws_may04.html

For several days, I've been receiving bursts of noise which sound similar to the old dial-up modems but faster and with more static. It seems to be random in when it starts, but when it does, there will be a burst about every 45-60 seconds for maybe 15 minutes and then it stops. I initially heard it on my repeater frequency (channel 15), and I thought perhaps my repeater was causing it. I heard it on simplex 15 as well, but a simplex channel with no tone engaged will hear repeater output. However, I turned my repeater off, and it continued to happen, so it's not due to anything I'm doing. The thing that puzzles me is that with a radio set to my repeater frequencies and receive tone engaged, I shouldn't be able to hear anything that doesn't use that tone, but I do. Can anyone enlighten me as to what may be causing this?

Asked and answered in the same post https://www.antenna-theory.com/definitions/desense.php It's not usually a problem when the receiver and transmitter are on the same frequency, but on a repeater, where you're transmitting on 1 frequency and listening on another, the transmitter will 'deafen' the receiving radio if they're too close. I actually did similar testing today w/ a radio I'd just installed in a car in the garage, and my kid standing out by the street to let me know how I was coming through.

It has been moved to Thursday nights at 7:30, the next meeting is on 7/24/2025. Sorry for any confusion and hope to hear from you this Thursday.

Yes. get them at least 50 feet apart and try again.

Totally newby here, so forgive me if either dumb question or answered elsewhere and I am not searching right. I have 2 identical radios (Baofeng UV-5G+'s) that I have configured to talk to the same repeater, one for me, one for my wife I have programmed them with the same channel information (used the Baofeng software, loaded same profile into each and confirmed) I am trying to test one, then the other, to be sure when I talk on one I hear it on the other, and vice-versa When I talk on one, I do NOT hear myself on the other I DO hear back from someone on the repeater saying they hear me loud and clear I am wondering if having both radios in the same room is causing one to overpower or cancel out the one listening. Anyone have any ideas?

It can be worse than that. Some cruise lines make money renting out radios to travelers who know their cell phones won't work at sea. Scanning around any of the many cruise ports in Florida leads to much hilarity as one listens to conversations about the buffet specials. Hopefully, the crew knows enough to not match the radio freqs with anything important. I've taken radios on cruises to foreign countries more than once. I ask the officers what freqs are used for such things as port operations, on-board comms, ship-to-ship, etc. and underline the fact that it's RX only, no TX, that I'm interested in. Most officers are cooperative and curious, others have told me to lock it in the safe and not to touch it for the remainder of the trip; apparently it is illegal to just listen to some channels in some places. I always bring the cheapest, POS CCR in the inventory in case it gets confiscated. Of course, one could avoid all this by just scanning on a hacked UV-5R; at least that's what I read on the internet.