Morse Code on GMRS

So I was way out in the boonies over the weekend and heard a single transmission in Morse Code on Channel 17.
I can’t interpret Morse Code so I’m totally clueless what it was. Who uses Morse Code on GMRS and why?

Some ham and GMRS repeaters periodically transmit an ID in CW (Morse Code), so it is possible that was what you received.


Is there a way to transmit my id in (CW) on gmrs?

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You are allowed to transmit your call sign in International Morse Code on a handheld or mobile GMRS radio, but I’ve never done it and I don’t know anyone personally who does. GMRS is intended for voice communications, not code, and is not a “hobby” service like ham radio. Repeaters do it because they are built for it, but most, if not all consumer GMRS transceivers are not.


Can you explain the “not a ‘hobby’” aspect of this? It’s curious that GMRS requires a license, while CB does not, and therefore is like Ham in that respect. I know what I use my gmrs for, but I’m still not clear on what it was envisioned to be fore.

Amateur radio is a hobby, and the service is designed to accommodate that. Hams use it for DXing contests, data transmissions, emergency backup communications, slow scan picture and television transmissions, home radio builds, and general experimentation with radio related technologies. It’s hobby stuff.

GMRS, on the other hand, has a completely different purpose. GMRS stands for General Mobile Radio Service, and means exactly that. It was created for general use by the public for personal voice to voice communications. Some groups may consider their use of GMRS as a hobby, but that’s not really what it’s for. It’s intended for families and individuals to communicate with each other for normal, ordinary, day-to-day tasks or activities, like you would on a telephone.

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CB used to require a license. GMRS was originally aimed at individuals and businesses who needed nationwide license coverage (regular commercial licensing is for a given area). This is why some of the now “legacy” group licenses belong to companies such a American Airlines, Delta, etc. The FCC did away with group licensing and eased up on itinerant licensing qualifications in commercial radio service.

For record most FCC rules state systems can ID either via voice, morse ID or even some predefined digital ID.

I agree 100% with the replies.
CW - what you call Morse Code, but actually ham radio uses International Morse Code - which is different than telegraphers Morse code - like what you see on an old western movies with telephone poles and batteries and a key on a desk.
The reason why YOU can’t do morse code on GMRS is because your radio is FM - Frequency Modulation.
Morse Code - CW - Ham Radio, uses a form of Amplitude Modulation where the key turns on and off the transmitter carrier in such a way that it produces a tone. The receiver on the other end receives the tone. The user uses their ears to hear the tone and decipher it into letters and numbers and punctuation etc.
The benefit to using cw is that it is more efficient, because the signal it produces is very narrow and it funnels all the transmitted power into that tone. SSB - Single Side Band, where you basically suppress one of the side bands and maybe even the carrier is a phone version of Amplitude Modulation. Single Side Band is more efficient.

Amplitude Modulation - the transmitter produces a carrier and two side bands. The receiver only uses one of the side bands, throws the other away. The carrier robs half or more of the power produces, yet it does no work. So its wasted power.

so you see, GMRS is a economical way for a person with no knowledge of radio or how it works to communicate locally, while Ham Radio is a more expensive version of radio both in terms of knowledge, time invested in learning the theory and taking multiple exams to obtain the licenses necessary to gain the privileges you desire. And the equipment, since most good amateur radio HF equipment would probably put you back $1500 or more, by the time you bought the radio, power supply, antenna, swr meter, dummy load, speaker, tower, coax, extra microphones and all other peripheral devices hams uses today , even computers used to communicate digitally with other hams all over the world. You can easily spend $8000 just on a good HF transceiver, $5,000 just on an entry level beam antenna set up.

If this sounds appealing to you, maybe you ought to look closer to amateur radio than GMRS, maybe you would make a good ham.

Maybe it is training? Somebody teaching people Morse? No qualifications required and people can try it for real. Maybe so that when they pass their ham exam they can have the extra skills? I know it’s not needed any longer, but on HF there is plenty of it around. It’s got no practical advantage on the FM band, especially when they generate the sound in the room, and capture it with the radio mic - that horrible tinny sound is harder to listen to voice!

Driving around the Kansas City area with my new MTX 275 Midland on scan mode, I often hear short bursts of CW on channel 15 & 17. Since I have yet to learn Morse, I’m guessing these are HAMS sending call signs. Someday I’ll decode one and contact them when my Tech Ham license is processed by the FCC - I passed the exam earlier today. :slight_smile: Now I get to go radio shopping next week. :slight_smile:

Congratulations. Just record a bit and then slow it down till you can hear each letter, than slow it down. However that’s for a rainy day. I guess the thing could be almost anything. I came across some Morse on our free short range PMR446 and it was some hams in training doing practice, and I turned CW identification on so I can check my business repeater reception. It sends out my business name and location every ten minutes and it just lets me know it’s working and active in the periods of no use. Learning CW is also a great across the table mind reading trick with a friend in restaurants. Been doing it with a friend for years and we’ve never told anyone how we do it. If your feet can touch under the table, you can do amazing mind reading tricks with the other guests writing things on serviettes! Rather silly now I actually write it down.

I have to think those “short bursts” are stations IDing in code.

Hams would NOT be operating on GMRS, at least operating as hams.

The CW you hear is a repeater identifying itself.

CW is a type of modulatuion. GMRS is not capable of CW. Morse code is an information code. GMRS stations are permitted to transmit their required station call sign using Morse code or orally. I have my call sign recorded in Morse code in 20 wpm tones as a sound file on my mobile phone, which I can play into the mic when necessary.

I guess some folk just use the term CW as an alternative to ‘Morse’ - I think the OP just wondered why? Oddly, I implemented the “CW Ident” feature on my UK Technically Assigned licences repeater. OFCOM don’t actually require it, but it’s handy for signal strength monitoring. Kenwood call it CW, which as you say, it isn’t!

To clarify, for technical and exactness, CW (Carrier Wave) uses Pulsing of the carrier wave on and off, comparable to how basic pre “Mark and Space” wired telegraphy used the presence of a a similar in a voltage sense to indicate pulses, and it was the spacing (there is and was a defined ratio of no sig to sig that’s proportional to the pulsed signal) separating the parts of the code packet indicating a character.

Morse Code is the encoding that is modulated (in this case, cycling the presence of a carrier) under conventional CW operations which defines the pattern of long and short sigs that define each character sent. That’s why we associated CW as in the sending of Morse code over radio.

However, the orignal (later) use of what became the basis of most telegraphy, mark-space signalling, which Morse technically conforms to in a sense, was again a wired telegraphy signalling method - originally still using a variant of morse code encoding but later evolved into a set of expanded character set tables of encoding which used more mark-space (equiv to ‘dot dash’ in Morse Code) combinations plus numeric and alpha shifts to define what was being sent as numeric or alphabet and some symbols were grouped in ‘numeric’, other as ‘alphabet’ and so -

So sending ‘THE QUICK BROWN FOX JUMPED OVER THE L:AZY DOG’ (disregarding the quotes) would use a Letter shift, followed by the appropriate mark-space combo for each letter - note it was still, at that stage, still CAPS only. ‘TESTING 123’ would use an Alpha shift followed by each letter combo, a space representation, a numeric shift code, followed by the encodings for each of the three digits.

TOR, as known commercially, and RTTY as known in the amateur radio world and generically (there are differences but they are more of a technical variation than outright separate modes of operation) using Baudot code, effectively replaced Morse and CW in most commercial and critically sensitive/required operations and as a mode of operation ‘RTTY’ (in the generic sense covering both) had the characteristic of being mostly as conditions/propagation tolerant CW, but ultimately, when your life depends on it and you have next to no resources, you can make a CW or (a bit more complex) emitter out of anything that generates an EM field - that’s the real value of old basic tech, near infinately implementable to any purpose your mind can make real.

There were many reasons why one was more effective than the other and survived commercially, but traditionally in radio, we used (up until the ITU regulations rendered it redundant in recent years) CW, by the use of Morse encoding, as the mandatory method of sending emergency beacons and it was still required that radio operators on ships could manually send and decode Morse from CW. The same ITU requirement that mandated HF operators had to be able to use Morse and CW was why in ham radio you needed (until nearly a decade back) you had to pass a CW test to be able to claim your HF element of the license (when i first got licensed, there was still the A & B class licenses, B being restricted to above 30Mhz but all modes still). This got rendered redundant by the use of expanded and more reliable satellite based relay technology meaning the integrity of the signal over an EM path was improved by the sending skywards to a distant (low earth and medium earth orbit) satellite and inter-links between the orbital satellites by passed the dependency (at extreme ranges) on good propagation and subsequently that even within a band segment at HF (where long dist and deep water emergency or response and general communications happened, VHF used within about 45 miles of shore).

Mark & Space telegraphy, which in various forms and variants became the basis of all generations of telegraphy after CW and Morse Code. Technically, if you send audible morse over a voice modulated system, it’s what’s known as MCW (modulated Carrier Wave), not CW. In fact, when you send it over FM, it’s almost technically a form of FSK - it’s grey area by technically true for MCW over DSB (AM) and SSB where it’s the actual AFSK modulation within DSB/SSB that makes it still FSK, given it uses two tones to represent ‘dot’ and ‘dash’ (just as post-Morse FSK used similar to create frequency shift offsets of carrier frequency to indicate the presence of signalling and differential of ‘mark’ and ‘space’.

In fact, anything using frequency offset shifting of the carrier is technically FSK, but FSK is mostly (and formally accurately) used with context of telegraphic sending and any sub-carrier content encapsulated within a telegraphic transmission.

So no matter how the content is embedded/modulated onto a carrier, no carrier or supressed carrier (two of a few variants of SSB), if you captured and listened to any modulated data transmission, despite the formation variations, it’s still mark and space.

For decades, there was little movement of the basic ‘RTTY’ cpncept, speeds changed as we moved from electromechanical to electronic sending, introduction of many forms of in-line error correction came and went, with FEC (forward error correction) being the longest lived EC system and still used in many forms of telegraphy in variants and expanded evolutions of.

So to address the CW ID elephant, CW ID sends are normally MCW but there are still some uses of pure CW for sending a CW ID but that uses a dual pair of TxCR modules each defined to each mode, the main Modulated AV/DV mode being the main content sending/receiving ‘set’ and the CW pair being triggered by time sequencing and/or pre/post/pre and post sending termination of the main modulated sends.

Why they, who you heard, were sending Morse as MCW, only they know, as someone else mentioned, it could simply be a legit required CW ID you caught out of context - but it could simply be a practise they use, or simply practise or even just keeping an old art alive. But when the SNR goes to ■■■■ over long distance on Analog FM, even modulated CW (due to the nature of two non-harmonically related ‘loud’ tones) is far easier to discriminate when the modulation is barely perceivable when the carrier is getting lost in the noise floor, so it still can be a good thing to have on hand. In fact, i’ve yet to see an LMR system who’s prescribed operating practises forbids the use of MCW, in most cases there is a requirement of some kind of ID usage at some random or occasional or prescribed interval and even when it’s not explicitly stated (mainly the case) in what form, MCW CW-ID’s either manually sent or MGM (machine generated) or even a short playback of a recording of your ID is mostly within the confines of most system, except where (usually) there is a prohibition against sending the contents of a recording or pre-scribed content of which the only one i know of that actually vehemently hammered home the not-permitted use of was the UK CB license (as it was when we had a license).

As Paul mentioned, beyond any requirement or general non-required use of CW ID’s, it’s still good practise for technical reasons, and if you ever happen to forget your mandatory requirement to occasionally ID yourself (where required), you’ve already technically addressed the memory lapse elephant. Even when i use sig gens, i have a MGM CW ID i can trigger, since sometimes you need to generate a source through a live antenna, at low mW ERP levels or lower of course. I even employ it when i experiment with ISM allocation modules and when i do GNU Radio controlled ISM allocation tests using an ADALM PLUTO (with a suitable additional tunable final filter for sanity and practise sake).

As for the ‘Hams would NOT be operating on GMRS, at least operating as hams.’, just don’t get me started on such BS comments since operating practise in the business world and leisure world of LMR that i’ve heard demonstrates how few even would know what truely good solid operating practise was if it was Godzilla and stomped them into the ground. ■■■■, i’ve even got a few Given that many modern dealers treat LMR as a commodity and care little about encouraging and promoting good practise when demoing units and systems, it’s not surprising many users don’t even note the basic universal guidance in most user guides, and if you got your practise knowledge third hand by someone who never had a clue to start with, you’re doomed as an op. Thankfully, in defence of the diminishing number of LMR vendors who operate solid practises and outlets, some of whom are ham radio outlets who also sell commercial gear to licensed (proof required) commercial users or run a training process pending license application, still exist and subsequently their mirror selves, professional commercial radio specialists who also embrace the ham radio market.