DX University™

  A Guide for DXers and DXpeditioners



The concept of QSO Mechanics describes to the process between the revelation of the initial full or partial call and the confirmation of the exchanged date during the QSO. It starts with the DXpedition operator signifying whom he is addressing, and ends with the last “QSL.” QSO mechanics includes sorting through the pileup for partial or complete call signs, persisting with the selected station. Verifying the DXer’s call sign and the confirmation of the DXer’s call sign. QSO mechanics may also be considered to include how the DX station approaches the next contact: Identifying and issuing instructions to callers for the next QSO.



The objective of those calling a DXpedition is to get their call signs correctly in the log in order to receive a confirmation. The DXpedition operator must make every effort to see that he has the correct call sign in the log and that the station worked knows that his call sign is correct in the log. Ending a QSO with a station’s call sign correctly in the log is the purpose of a contact. Doing so marks the difference between DXpeditions and contests. In a contest, accuracy is important, but accuracy is a trade-off against time. Some top contesters are willing to trade accuracy for speed. The extent to which they can do that successfully can increase their score. In DXpeditioning accuracy is important but time is of somewhat less importance, so a much greater effort toward accuracy should be made. In fact, time should be spent if necessary in order to assure accuracy and recognition.

Accomplishing the desired accuracy – minimizing the bust rate – when DXpeditioning requires that the DX operator follow the proper format for a good contact. When listening on CW, if the DXpedition operator hears a complete and correct call sign, he will send that call and a signal report: W5XYZ 5NN. W5XYZ should respond with only a signal report: “QSL 5NN TU.” On SSB, the DXpedition operator will say W5XYZ Five Nine, and W5XYZ will respond “QSL Five Nine Thanks.”

If the DXpedition operator hears only a partial, the routine is the same except that the DXer should not send a signal report until the DXpedition operator has his call sign correctly. On CW, the DXpedition operator says “W5[?]YZ 5NN”. W5XYZ responds “W5XYZ”. The DXpedition op then says “W5XYZ 5NN”, and then W5XYZ says “QSL 5NN TU”.

So, if the call sign is correct, the DXer should not send his call again. To some extent this procedure is a product of computer logging. The assumption is that the DX op has entered a call into his logging program and caused the program to send the call. If it’s correct, and he the DX op subsequently hears nothing that suggests that it is NOT correct, he will leave it alone. If the DX operator hears a call sign sent again, he has reason to believe he may have entered it in error. Many times I have heard a QSO lost – particularly on 160M – because the DXer sent his call again, and the DX operator, perhaps suffering QSB, had second thoughts about whether he had the call correct. He got it wrong the next time, and by that time, QSB had made the DXer’s signal inaudible. The QSO was lost!

In another case, the operator picks at worst a "partial" call sign from the pile. If the DX op has only a partial call, the DXer should reply by sending his full call again. When the station repeats his call sign and the DX operator has copied it correctly he must send the corrected call sign back to the station. It is totally inadequate to simply say "QSL", even if the call sign has been copied correctly, since the station worked can't know that his call has been correctly logged. In extreme cases such as a very rare DX station, where accuracy is most important, The DXpedition operator might send a second confirmation.. That is, the DXpedition operator can ask the caller if he has heard his call repeated correctly. Failure to follow these procedures will almost certainly result in an elevated duplicate rate. Those expeditioners who complain of unnecessary dupes should take a close look at their operating procedure. It takes two to make a good QSO. Often the DX operator is practicing poor QSO mechanics.

In recent years the popularity of the on-line log, either updated while the DXpedition is in progress or kept in real time has blossomed. It is possible for DXers and DXpeditioners to become sloppy in their operating opting to rely on an on-line log to determine whether they made a “good contact.” One has to wonder whether a QSO listed in an on-line log is really a valid two-way QSO, if either party has to determine the validity through this method. In the extreme, it is possible for a DXer to simply send his call automatically until it shows up in the on-line log, and then stop transmitting. This is called “Beacon DXing,” and it was originally meant as a joke. Today, its mention is hardly a joke.



Although not desirable, responding to partial call signs in a large pileup is often necessary. Exactly how this is done is important. Responding to a call sign that is too partial is an invitation to many operators to call again. The reason for responding to a partial in the first place is to cut the size of the pileup that responds. If you hear a W5 and you say “Who is the W5?” Every W5 in theUSA, and many other 5s in the rest of the world, will call. In fact, any “?” sent seems to be an invitation for almost everyone to call again. The goal of making the pile smaller might have been defeated. On the other hand, this is sometimes a workable situation because although all W5s might call, many others   won’t. In general, it is much better to hear more than just “W5”. Several letters of the suffix are far superior, and a strong case can be made for waiting at least for these additional letters.

Part of the reason for the noted response to “?” is that many DXers don’t copy code well enough to understand what you are asking. At speeds beyond their capability they can copy their call signs and maybe the question mark. If they hear their call sign, that’s great. If they hear “?” they are definitely ready to call again. It is important for you the DXpedition operator to copy as much of a call sign as possible – at least three characters. Anything less should be avoided. More than three is better.

Another reason for the response to “?” is just hope or worse. Calling while the DX is asking for a specific complete call will seem out of place for most DXers. If there is any question (“?”) however, some will be able to justify it. This might make more sense to the DXer who has heard the DX operator actually respond to something other than that he asked for. Therefore, it is extremely important for a DXpedition operator to establish and follow strict rules about who to work and when. If he asks for a W5, he should never answer anything else before terminating that effort and moving on.

This leads to another aspect of successful QSO mechanics, which is persistence. When the DXpeditioner responds to a partial call sign it is imperative that he persist with that station until he has the complete call. If he does not persist he in effect invites all othercallers to call out of turn during his QSOs. DXers have been very clear about how they feel on this issue: If the DX operator does not persist with a call sign then calling out of turn is justified – even if it is their calling out of turn that prevents the DX from being able to copy the desired call sign! The operator must be extremely firm on this issue.


In it always important that thecallers know the call sign of the DX station. Many DXpeditioners sign their calls after each QSO, including instructions as part of signing. I will maintain that it is important for thecallers to know whom they are calling. If for some reason they are universally aware, it is probably not necessary to sign after each Q. Instructions, on the other hand should be repeated after each QSO, so including your call isn’t a major issue. Therefore, the question is how often the DXpedition operator should send his own call sign.

There are a number of options. If the operator dislikes responding to queries, he can send his call frequently. If the call sign is short, it will take little time to do this and it can even be a personal signature. A DXpedition is not a contest, however, and no one really needs the call sign immediately. If the expedition is a major one, it is likely that even the neophyte DXer will know whom he is calling (especially if designated frequencies are adhered to) and relatively infrequent IDs will suffice. Station identification is usually available on the various spotting networks, although DXers should be aware of the fact that these “spots” are not always accurate. If another expedition is in progress it becomes very important to identify frequently since there can be confusion over just which station has been worked.

The call sign of the DXpedition station should be sent often enough so that virtually all of the stations calling know whom they are calling. If callers start asking you who you are, you have not been identifying frequently enough. Depending on the QSO rate, identifying at least once every 3rd or 4th QSO or once every minute could be sufficient. Whether or not a call sign is given, each QSO should be ended with instructions: “UP,” UP5,” “NA,” “EU UP5,” “NA FIVES,” etc.