Morse Code Q Codes: QTH, QSL, QRZ, QRM, QRS & More

Q codes are three-letter groups that all begin with Q, each standing for a complete question or statement agreed internationally for radiotelegraphy. Send one with a question mark and it asks; send it without and it answers or advises. QTH? means “What is your location?”, and QTH LONDON means “My location is London.” Amateur CW operators use about two dozen of them in almost every contact.

This page lists the Q codes you will actually hear on the amateur bands, with the Morse for each (press play to hear the rhythm), the official wording from ITU-R M.1172, and where amateur usage has drifted from that wording.

What Q codes are and where they came from

The Q code is an international set of abbreviations for radio operators. The Q prefix works well because in English and many other languages Q is almost always followed by U, so a Q followed by any other letter stands out as a code rather than plain text.

A list of Q abbreviations was already part of the service regulations of the 1912 International Radiotelegraph Convention signed in London. Several groups in that list, including QRO and QRP for power, QRQ and QRS for sending speed and QRT for stop transmitting, carry essentially the same meaning today.

The current reference is Recommendation ITU-R M.1172, “Miscellaneous abbreviations and signals to be used for radiocommunications in the maritime mobile service” (1995). Its Q code section covers groups from QOA to QUZ, with QOA to QQZ reserved for the maritime mobile service.

Amateurs adopted a practical subset. The ARRL even named its magazine QST after a Q signal, and its Q-signals operating aid still lists “the ones used most often on the air.” Two things follow from this history:

• The official wording is maritime and commercial. QTH officially asks for a position in latitude and longitude; QSO officially asks whether you can communicate with another station directly or by relay.
• Amateur usage is looser. On the ham bands QTH means your town, QSO means a contact, and QST is an amateur-only general call. This guide flags each case.

Q codes are different from CW abbreviations such as CQ, DE, TNX and 73, which are not Q groups at all. Those have their own guide: Morse code abbreviations. Procedural signals such as AR, SK and KN are covered in the homepage prosign table.

How to read a Q code: question, statement, extras

ITU-R M.1172 sets out a few simple rules. Once you know them, any Q code on the list becomes usable without memorising separate “question” and “answer” versions.

1. A question mark turns it into a question. In radiotelegraphy a Q code is a question only when followed by the question mark. QRS? means “Shall I send more slowly?”
2. Without a question mark it answers or advises. QRS on its own means “Send more slowly.”
3. Extra information follows the code. Figures, frequencies, call signs and place names complete the meaning, sent in the order the table shows. QRS 12 means “Send more slowly, 12 words per minute.”
4. In a question with extra information, the question mark goes last. The recommendation says the question mark should follow the added information, so the complete question comes before the ?.
5. Numbered scales take a figure. Codes such as QRM and QRN have a 1 to 5 scale, sent immediately after the code. QRM 3 means “Your transmission is being interfered with moderately.”
6. C and NO add yes or no. Certain Q codes take an affirmative or negative sense when followed by the letter C or the letters NO.
7. Times are UTC unless the exchange says otherwise.

Notice how often the question mark appears. It is a six-element character, so hearing it cleanly matters: ..--... If you are not sure you copied a Q code as a question or a statement, listen for that distinctive di-di-dah-dah-di-dit at the end.

Q codes list for CW operators

The table below covers the Q codes that appear regularly in amateur CW. The question and statement columns follow the ITU-R M.1172 wording, shortened only where the original lists optional extras (shown as ”…”). The last column describes typical amateur use, which sometimes goes beyond the official meaning.

Two more groups deserve a note. QRK asks about intelligibility and QSA about signal strength, each on a 1 to 5 scale in M.1172. On CW they have been almost entirely replaced by the RST system, so a report like 599 is not a Q code at all. See RST signal reports for what those three digits mean.

QTH: your location

QTH is probably the Q code most people search for. Officially, QTH? asks “What is your position in latitude and longitude (or according to any other indication)?”, which made sense for ships at sea. Amateurs use it more loosely: QTH is the place your station is, usually a town or city.

In a CW contact you rarely send QTH? as a bare question. The usual pattern is to give your own location early and let the other operator reply with theirs. Place names are commonly sent twice so a missed letter can be filled in from the repeat.

On VHF and above, operators often exchange a grid locator (a short letter-and-number code for a map square) alongside or instead of a town. You may also hear “my home QTH” on phone, where QTH has become an everyday noun.

QSL: acknowledging receipt, and QSL cards

QSL means “I am acknowledging receipt.” QSL? asks “Can you acknowledge receipt?” On CW, QSL confirms that you copied something, although many operators send the shorter R (received) for routine acknowledgements.

The same three letters also name the QSL card: a postcard that confirms a contact between two stations, with call signs, date, time in UTC, band, mode and signal report. Cards travel direct by post or through the QSL bureaus run by national amateur radio societies, and electronic confirmation systems are now widely used as well. Asking for a card on CW often looks like “PSE QSL” near the end of the contact.

QSL is easy to overuse. In a fast contest exchange there is no need to send QSL, R or TU just to confirm a report; if the other station did not copy it, they will ask again.

QRZ: who is calling me?

QRZ has exactly one meaning: “Who is calling me?” Send it as QRZ? when you called CQ, heard one or more stations answer, and could not copy any of their call signs.

Because the meaning is so specific, QRZ is also one of the most misused Q codes:

• Do not end a CQ with QRZ. Nobody has called you yet, so there is nothing to ask about.
• Do not use QRZ to mean “Who is on this frequency?” If you want to know who is operating, operating guides suggest sending CALL? together with your own call sign.
• Do not send QRZ? after copying part of a call. If you caught a fragment, send the fragment followed by AGN (again). Sending QRZ? invites the whole pile of callers to start again.

The name is familiar outside the bands too: a popular online call sign lookup site takes its name from this code.

QRL?: is this frequency in use?

Officially QRL? asks “Are you busy?” and QRL answers “I am busy. Please do not interfere.” On the amateur bands, QRL? is the standard way to check whether a frequency that sounds empty is really free before you call CQ. You may be hearing only one side of a contact because of propagation.

Send QRL? (operating guides suggest at least twice, a few seconds apart) and listen between tries. If the frequency is busy you may hear QRL, R, C, or a request to QSY. Two habits to avoid: sending a bare question mark (it says you asked something without saying what), and adding K after QRL?, which hands the frequency to a station that may not exist.

QRM vs QRN: interference or static?

These two are easy to mix up because both describe noise.

A simple memory aid: the M in QRM can stand for “man-made”, the N in QRN for “natural”. On CW, the scale figure is optional but useful: “QRN 4” tells the other operator why you may need repeats.

Notice the direction of the official wording. QRM tells the other station that their transmission is being interfered with at your end, while QRN says you are troubled by static. In casual amateur use both are simply “I have interference” or “there is static here.”

QRS vs QRQ: slower or faster?

QRS means “Send more slowly” and QRQ means “Send faster.” Both can take a speed in words per minute.

QRS is the one you will use far more. There is no shame in it: operating guides advise never sending faster than you can copy and replying at the speed of the station you are calling. Operators generally slow down when asked, and adding a figure, as in “QRS 12”, makes the request precise.

If you are learning, QRS is also the name given to slow-speed CW activity in general. The what is CW guide explains how CW contacts work if you are new to the mode.

QRQ is rarer. You might send it when the other operator is sending slowly for your benefit and you are copying comfortably.

QSO: from “can you communicate” to “a contact”

The ITU meaning of QSO is “Can you communicate with … direct (or by relay)?” In amateur radio it has become a noun: a QSO is a contact, a two-way exchange between stations. You will hear “TNX QSO” (thanks for the contact) at the end of many CW contacts and “a nice QSO” on phone. A single contact is made of several transmissions, or overs, between the stations.

QSY: change frequency

QSY means “Change to transmission on another frequency,” and it can include the new frequency. QSY? asks “Shall I change to another frequency?”

Operators use it to move a contact off a busy calling frequency, to escape QRM, or to let a net continue. On HF the frequency is normally given in kHz, as in the example above.

QRT: stop sending

QRT officially means “Stop sending,” and QRT? asks “Shall I stop sending?” In amateur use it mostly means going off the air: “QRT” or “going QRT” at the end of a session tells others you are closing the station, not just ending one contact.

That distinction matters. Ending one contact is done with a procedural signal (a prosign) rather than a Q code.

Example CW exchange using Q codes

Here is a short, typical ragchew contact with the Q codes in context. K1ABC and G4XYZ are example call signs used for illustration. Non-Q abbreviations such as CQ, DE, TNX, UR, HW and 73 have their own guide, and so do the three-digit signal reports; both are linked in the last section.

Here is how Ann’s line 5 information sounds once you strip out the call signs:

A second, shorter example shows QRZ used correctly. K1ABC calls CQ and hears several weak stations at once:

1. K1ABC: QRZ? K1ABC (Who is calling me?)
2. Stations call again. K1ABC now copies only a fragment ending in 4X.
3. K1ABC: 4X? AGN K (the fragment, a question mark and “again”, rather than another QRZ?)
4. G4XYZ: G4XYZ G4XYZ

Later, if the frequency gets crowded, either operator might send “QSY 7030?” (Shall I change to 7030 kHz?) and, if the answer is R or C, both move.

Common Q code mistakes

Most errors come from treating Q codes as loose slang rather than precise questions and statements.

1. Dropping the question mark. QTH gives a location; QTH? asks for one. On CW the question mark is the only thing that separates them.
2. Putting the question mark in the wrong place. When extra information follows a Q code in a question, ITU-R M.1172 puts the question mark after that information.
3. Using QRZ as “anyone there?” QRZ? asks who called you. It does not end a CQ and does not ask who is on the frequency.
4. Sending ? instead of QRL? A lone question mark asks nothing specific.
5. Mixing up QRM and QRN. QRM is interference from transmissions; QRN is static.
6. Reversing QRS and QRQ. Asking a nervous beginner to send faster is not the kind of help you meant.
7. Assuming the ITU meaning always applies. An operator asking QTH? on the ham bands wants a town, not latitude and longitude, and QST has no ITU meaning at all.
8. Adding /QRP to your call sign. QRP is not part of a call sign, and a /QRP suffix is not permitted in many countries. Send “QRP” separately, after your call, if you want to mention it.
9. Stacking Q codes on voice. A few (QTH, QSL, QSY, QRM) are widely understood on phone, but plain language is clearer and just as short when spoken.

How Q codes fit with abbreviations, prosigns and RST

CW contacts mix four kinds of shorthand. Knowing which is which saves confusion when you look something up.

To hear any Q code or full exchange line at your own speed, type it into the Morse Code Translator and press Play. Learning Q codes as sound patterns, rather than as written letters, pays off once you start copying real contacts; the guide on decoding Morse code by ear covers that skill.