DX pileups


Audio Studies

The audio files listed on this page illustrate various situations that are often heard in DX pileups. They are excerpts from real pileups recorded directly off the air in MP3 format. The files are recorded in STEREO with the DX station on one channel, and the pileup on the other. For best results listen in stereo with stereo headphones or ear buds. While you listen, imagine tuning the pileup looking for the station the DX operator is working. Studying these recordings could help you to gain an advantage.

Other than length, no editing of any sort has been done. The text included with each button may explain what is contained in the recording, or it may simply allow the listener to determine for him/herself what is happening. Additional recordings will be added from time to time. You can make and study your own recordings with relatively simple equipment.

STEREO recording of T48RRC, 12. February, 2013 on 17M CW at 2145Z. He is possibly preparing for the 2013 ARRL DX CW contest. He is working mostly JAs. He is listening UP about 2 kHz, but neglecting to indicate where to call, UP in this case.

STEREO recording of 6W/HA0NAR on 3521 kHz, 13. February, 2013 at 0410Z. Note that hne is slowing his code when asking callers to call UP, but not every QSO. Also, note some timing problems — starting his transmissions before the other station has finished. (This could be caused by poor copy.)

STEREO recording of TX5K on Clipperton Island, 6. March, 2013. Operation is on 15 meter CW. The pileup receiver is set for 2.4 kHz bandwidth. TX5K Working a very large pileup of European stations. Note that even though the speed is high, the operator is not identifying often and it not sending “UP” after each QSO, there is very little QRM or disruption on the DX frequency.

STEREO recording of TX5K on 75M SSB. 0200Z on 7. March, 2013. XE1L operating by the numbers.

STEREO recording of TX5K – 17M SSB – 7. March, 2013. “I am working NA now, Europe please stand by.” (Note: DXpeditions usually “target” the most difficult areas. This calls for working the targeted areas whenever the band(s) is open to that area. There is NEVER any difficulty working the less difficult areas.)

STEREO recording of 9M4SLL, 11. March, 2013, 1655Z, 20 CW. Good signal in west USA. Note: High speed, short partials, many calling are not pausing when partial response is requested. Code readers?

STEREO recording of 9M4SLL, 12. March, 2013 at 0042Z on 12M CW, (8 minutes). Small pileup primarily to the West Coast of the USA.

STEREO recording of 9M4SLL, 21.298 mHz SSB, listening 300 – 310. Working both Europe and USA/VE.

STEREO recording of 9M4SLL on 80M CW, 15 March at 1225Z. The operator at 9M4SLL isn’t hearing very well. (This QTH is known to have a high noise level on the low bands.) He is generally persisting with the calls he has heard. His speed is appropriate. It might seem that he could tune a wider range, but he probably has a very different picture of the pileup than we hear on the recording. It appears that many callers can’t hear well enough to call. Some calls stand out in the pileup. This is a demonstration of a common problem: “When in doubt call!”

STEREO recording of 9M4SLL on 80M CW, 15 March, 2013 at 1245Z. This is a continution of the previous recording. Still, many stations can’t hear well enough to be calling.

STEREO recording of John, G4IRN at XR0YG on 15M CW working the US and some Japan early in the operation. John is definitely one of the better pileup opeators. The pileup is huge. His procedure is working well — he’s sending 35 WPM, probably too fast, in general, but it’s working. Later in the operation this speed would not work so well — There is no DQRM (deliberate QRM), just a few calling on his frequency as he’s sending “up” after every QSO. Note how fast John finds the next station. This sequence would also be good practice for finding the station the DX op is working. What is happening, though is that a large number of callers are calling again even after he’s identified a station — maybe a partial — and sent the report. This may be due to the high speed, callers not understanding who he has come back to, or simply not beliving that he found someone so quickly(!)

Martti, OH2BH operating Z81X, South Sudan on 21.290 SSB at about 1920Z, 29.April, 2013. Martti listening initially for W6/W7 in his usual calming style. He didn’t work many 6/7 in this piece, but he is working NA and listening periodically for 6/7. The pileup is difficult to hear in Wyoming, but I did find many of the stations he was working. Note the lack of commotion.

This is a stereo recording of FO/UT6UD runninig a 17m pileup. It was made on 7. July. 2013. The FO channel is narrow bandwidth, while the pileup channel is wide, up to 4 kHz. We tried to find as many of the callers as possible. The pileup consists mostly of Ws along with some Europeans and a few JAs. Here’s a quiz: Suggest in detail where improvements could be made in the operating on each side of the pileup? Send your analysis and suggestions to info@dxuniversity.com.

(Documents TOP SECRET)

This is a mono recording by Tom Warren, K3TW of Robert, S53R operating HV0A, 17M on July 14, 2013. No doubt, Robert is one of the world’s premier pileup operators. Although his rate is good, his speed is high, at 38 wpm. Although we can’t hear the pileup in this mono recording, I suspect that the pile isn’t huge. If it were larger, his high CW speed could be a problem. Even in this recording, many DXers aren’t aware that he is listening up, and some minor chaos ensues on his frequency. (Thanks G3SXW)