I'm listening to (or let's say I'm trying to participate in) a contest (or perhaps Field Day), using SSB.
I noticed that a station would, after completing a contact, sometimes say “CQ” and sometimes say “QRZ”. In either case, other stations then reply with their callsigns. What's the difference, and when should I attempt contact?
This became clear to me after a bit of time to think, but it wasn't at all clear on initially jumping in. It helps to know the formal definitions of the codes used:
CQ is “Calling any station”. The station is asking for (new) contacts from anyone.
QRZ? is “Who is calling me”. The station is asking for a calling station to repeat their callsign. Only a station which has already attempted to contact them should speak at this time.
In my observations of actual contests, QRZ seems to be commonly used to mean “Someone other than the station I just worked, please call”, but while trying to research this answer I found one document claiming that it is appropriate only for “could not copy previous call” and not for “I want someone else from the pileup now” — but I also found a bunch of other mutually contradictory advice.
During contests, a popular station (say DX) has a pileup with lots of stations trying to make contact. A station will often merely say QRZ for picking up someone from the pileup. Thus, in this I am agreeing with the previous answer but with the following comment. I believe that this method of saying QRZ is now so popular in this pileup situation (that is, commonly done by many) that it has actually changed the use of QRZ over the years from its original intent of not fully copying a call sign or questioning the caller to repeat his call sign.
Whether it is correct to use QRZ in this way -- makes no difference -- this is what people are doing.
As said by other answerers, it's typically the station announcing 'I'm ready for more contacts at this time.' It doesn't necessarily have to be a DX station, but any station that is attracting a lot of traffic during contests. It is kind of informal usage, as Kevid Reid mentioned, the official QRZ definition is 'who is calling me?', and CQ means 'calling all stations'. The contest station will usually only use CQ if they're not getting responses.
Typically, when a contest station says QRZ, you should reply by saying your callsign once, and quickly, especially if there is a pile-up. If the operator heard you, he will repeat back your callsign, and/or parts of it if he/she only caught part of it. It is considered very rude to repeat your callsign many times. One of the worst examples I've heard was after a DX station said QRZ, a station responded with their callsign and 'I know you're hearing me, just answer and I'll stop calling!' and 'I'm just going to keep calling until you answer me!'
This just causes more irritation to those trying to communicate, especially when the operator is talking over those who are in communication. So best practice is to say your callsign once. If you're having trouble getting through, patience is the best way to get the contact. Just keep trying, saying your callsign once immediately after they say 'QRZ' Don't be discouraged if you hear stronger, clearer stations first. They'll get serviced, and the station will get around to you. They often want to make the contact as much as you do, so they'll be on the air for a while until the pile-up dies down!
Feel free to say your callsign after either CQ or QRZ. The best thing to do is to listen for a while, and notice which stations are being responded to. Sometime operators will prematurely respond with their callsign, without waiting to hear if the other station has finished broadcasting. It's about %80 timing and %20 luck!
And, as always, good luck and 73!
The answer is very simple: a contest station "running" a frequency calls "QRZ?" because it is faster than calling CQ and giving the call sign. The station running the frequency isn't trying to get only people who have called before to call when he or she sends "QRZ?".
The station running the frequency can't call "QRZ?" forever, because soon new stations on the frequency won't know what the running station's call sign is (unless they are using a spotting network). To have stations ask what the running station's call sign is slows down the run rate, so a good contester will remember to call CQ with the call sign periodically.
"Search & pounce" stations trying to work the station running the frequency can respond to either "QRZ?" and "CQ", assuming that the running station's call sign is known. One should pay attention to the timing so as to call at the correct moment, because a mistimed call can temporarily tie up the frequency for everyone and especially irk the running station. Contesting is all about making simple contacts very efficiently, so it's important to understand and work with the running station's rhythm.
QRZ seems to be commonly used to mean “Someone other than the station I just worked, please call” This is the way I always understood it.
but while trying to research this answer I found one document claiming that it is appropriate only for “could not copy previous call” and not for “I want someone else from the pileup now” — but I also found a bunch of other mutually contradictory advice. To me the QRZ call after a finished QSO means "Call anyone, I have noticed there were other stations calling me b efore my lkatest QSO."
If I did not see any other station on my waterfall after finishing a QSO I would call CQ and not QRZ after completion.
CQ is a general call. Something like 'anyone wants to establish contact with me?'
QRZ means 'I think someone answered (or called me), but I couldn't really get the callsign. Please repeat your call' It is meant mainly after a CQ and not understanding the reply.
In contests, where communications tend to be somewhat chaotic, QRZ is sometimes used instead CQ when stations are already queueing up to make a contact.
Both can be used in telegraphy and phone, though QRZ is less used there... But there is a difference in meaning.
