Contacter l'auteur / Contact the author

Recherche dans ce site / Search in this site

 

 

CQ DX for a SWL

Working with the long path (III)

To hear far stations (DX), a solution of compromize can be found in listening for example in automn to the 20-10m bands searching emitters during the local morning (before 0800 UTC), in the afternoon (around 1200 UTC) or in the evening (around 2200 UTC).

Two paths can be used : the short path (long circle), direct, where shortwaves travel in the sunlight to the far stations at relativity low altitudes (E, F1, F2-layer) or the long path (off-long circle), where shortwaves travel "backward", first to the side of the Earth plunged into darkness and at higher altitude (F-layer) to reach the remote DX stations on the sunside, reaching them "from behind". The path is much longer, for example 23000 km vs. 16000 to reach VK3, but signals are often much clearer with little QSB, because the ionosphere is less disturbed. You can receive a VK station between S4 using a dipole and over S6 using a beam.

At left, an example of opportunity using back radiation of beams and long path : listening by 2200 UTC a QSO between Mike, in CP, and an EA station (first row) I suddently heard a ZL station calling CP (bottom row). In fact the rear side of Mike's beam was oriented toward South Pacific, and ZL was on its path. On my side if the CP arrived 57 I heard the ZL weakly, 53, as his voice propagated over 14000 km to reach me in ON. What a QSO ! Similar configurations may occur with all countries. At right, the home-made 10-element Yagi used by Cyril, F5OUX to work VK/ZL stations on 10 meter (see below recordings of his QSOs).

Of course a SWL cannot control this path. But in the past I have used such stratagems with OMs from South America for example calling Europe in summer by 2200 UTC and receiving a contact with VK or ZL with the rear side of their beam. A similar configuration occured by 1600 UTC with a 9K station bearing to Europe and who heard a YB in his back. I usually receive these far countries with a signal strength less than S5 using a dipole. They are not strong but readable.

Even if this task can be accomplished regularly, that remains a performance using an ordinary wire antenna but also for the listener who has sometimes to stay awake long after midnight or wake up with birds !

To be complete, one must tell that the opportunity to work (or listen) or not a DX station using one path or another is quite hard to predict. First such openings are determined by the activity of the ionosphere. It it obvious for example that during a geomagnetic storm occuring at high latitudes, it will be useless trying to work or listen to northern stations (at a few exceptions). There is probably a radio blackout over 50 of latitude and no amateur will be able to transmit by shortwaves during a few hours. This event is very recognizable if you work from those latitudes because most bands from 20m and above, sometimes the lower too, are empty, without the least activity excepting a huge background QRM.

As explained on the previous page, the status of the ionosphere is also determined by the MUF. I remind you that if at both the transmitting and the receiving stations the MUF is for example 21 MHz, short distance propagation (3000 km) is open between both stations up to that frequency, but not above, and the signal will be hear over the complete path. This is only using an antenna showing a low takeoff angle that you might overtakes the MUF at longer distance. At last, a strong activity of the E-layer, or a MUF below the E-layer will always reduce your chance to capture far DX.

F5OUX working VK/ZL stations on 10m

QSO with VK4CQ at 00:30 UTC on 28.430 MHz, skip distance of 23516 km, SSN=36. 10-element beam, 50W, 21 May 2015.

QSO with ZL2OK, VK4CZ and ZL2FT on 28.430 MHz.

10-element beam, 50W, same date.

QSO with ZL3TEN/B on 28.228 MHz with 10W and l/4 vertical, same date.

Documents F5OUX.

Listening to DX networks

Now if you do not want searching for DX stations hours long in browzing frequencies, there is another efficient solution : listeing to DX networks. Here are some DX networks that you can try to listen or to work :

- The European DX network working on 14.242 MHz (summer) or 7.045 MHz (winter) from 1500 UTC on week days and from 0600 UTC on weekends. Thanks to the net control who manages QSOs by list, you could hear radio amateurs stations from many far countries or from very small entities, including LX when I am QRV, Hi!

- The 247 DX Net, a north american network is working on 14.247-14.250 MHz from 2000 UTC except Sundays, a good time for Europeans to capture many central american and Caribbean stations among other DX. The group has opened a Facebook account.

- The Brasilian network (BRYLA) is regularly in QSO with YL's and works on wednesday's on 14.248 MHz from 1900/2100 UTC.

It is complete with the Brazil DX Net working daily on 28.430 MHz from 1200/1400 UTC and weekends on 14.222 MHz at 1800/1900 UTC.

Note that the frequency of 14.222 MHz is also used by YL Pacific DX net on mondays at 0600 UTC, and YL Triple Two net on Mondays from 0530 UTC.

- The Africana net is working every day on 21.355 MHz from 1300 UTC or preferably 1800 UTC allowing you to listen amateurs from rare african countries, from SU to ZS but also from other continents like CO or HH.

- The Family hour network works on two different times and QRG, on 14.245 MHz from 1400 UTC and on 21.350 MHz from 1730 UTC.

- The famous W.A.B.A. network is on the air on monday's from 1700 UTC on 21.275 MHz (summer time) and will offer you one of the rare opportunities to hear (or work) Antarctic bases and stations.

At last, you will also find information about DX-peditions on DX World website, as well on Facebook groups DX-World and DX News.

Most DX stations can be hear (and work) with small antennas like magnetic loops, 6m high vertical and dipoles 20 to 40m long, even tight at low height (4-6m only). Of course the larger and higher the antenna the better receive.

If you work with a high gain directive array (beam, quad, loop), on weekends and with good ears you can hear several remote networks if you are searching rare DX entities for Asia and Pacific, including military and maritimes networks. Of course due to the time shift, most of them work when europeans are asleep.

I have tried to list some of them in the following Excel sheet and AC6V keeps a list update At last, Marius Rensen from HF-Fax maintains also a list of ham maritime mobiles net.

All these networks are not necessary QRV the day listed. Communications always depend on the propagation and can be subject to atmospheric noise or static, interference or fading, as much perturbations that may convince an amateur to QRT until the band is clearer or open again.

For an european DXer, remote networks like Pacific Island, Oceania DX Group or China DX are also more difficult to listen to if these amateurs to not bear their antenna in your direction, even though. So don't try to hear them with a small dipole and a short vertical, their signal is usually much too weak, except if they are in QSO with stations right in your direction. Most of the time, you need a directive array to hear them in good conditions.

To watch: Yaesu FTDX5000 filtering noise by G6DQK

DXNet activity on 40m managed by ON7TQ

QSO with DX entities

E41WT in Palestine working MS0IXD on 20m, 15:59 UTC, June 2015

3DA0TM in Swaziland calling CQ on 20m, 16:45 UTC, June 2015, QRN

4V200YH in Haiti on 40m, feb 2004

VP8THU in South Sandwich working GM4WJA on 10m, Jan 2002

8Q7CQ in Maldives isl., listening 5-7 up on 20m, 18:45 UTC, June 2015

AH0J in Mariana island working OH2FNR, DC9XU and others on 17m, 15:40 UTC, June 2015, QRN

T31MY2 in Central Kiribati working US stations on 12m, Feb 2003

DP1POL in Antarctica in QSO, 14.253 MHz, 23:59 UT, March 2003

Documents LX4SKY. Listen to more QSO.

Listen to contests

Another opportunity to listen to DX stations is to follow contests. Of course, the content of these QSO is reduced to the call sign and some numbers, not at all like a classic traffic, but if you want to increase your DXCC, WAZ or WPX score, it is till the fastest method.

There are many contests each year, almost one each week, to name those organized by ARRL and CQ Magazine :

- CQ WW : SSB in October and CW in November

- CQ WPX : SSB in March and CW in May

- DX contest : CW in February and SSB in March

- IARU contest : July.

without to forget VHF, UHF, EME, QRP and other QSO Party contests.

The CQ WW is by far the main HF contest. In 2014, close to 8300 SSB and 7600 CW logs where returned to CQ Magazine.

As most contests, CQ WW lasts 48 hours non-stop. During these weekends thousand amateurs, single or multi (gathered in teams), are QRV on all HF bands except on WARC. At daytime there is no one kHz that is not used ! Even bands segments usually free are at this occasion crowded ! 

This situation is still worse of low bands and mainly on 40m were stations are placed a fraction of kHz from each another, still closer than during an ordinary weekend ! It is in such situations that amateurs appreciate a performing receiver equipped with the best DSP to reject QRM generated by near stations, HI!

To watch : K5TR in CQ WPX SSB contest - GJ3A in CQ WW SSB contest

CQ contest

Deutch Kingdom contest, P43A in Aruba working M0MCV on 20m, 20:48 UTC, June 2015

CQ Seanet contest, JA3AOP on 15m, 16:35 UTC, June 2015

IARU Contest 2003, R7HQ near Moscow (ops RV1AW, Arno) working 77 stations in 16 minutes on 20m. Document RU1A

CQ WPX Contest 2002, AL1G in Alaska working KL7FH on 15m, recorded by KB9UWU

CQ WPX Contest 2001, WL7E in Alaska and WL7RA (both VFOs work simultaneously on the transceiver)

Listen to more QSO.

During these contests, you have all chances to hear stations in most CQ zones (there are 40). I remember that as SWL and using a long wire antenna 40 m long, I heard 65 DX entities during a weekend (being QRV 2x 12 hours) and as amateur I worked as many.

The best competitors using beams work up to 150 DX entities - three to four times more than a beginner -, including small entities like Marion island, Macao or Galapagos islands to name a few. You rarely hear them and amateurs have few opportunities to work these stations, but at this occasion there are tens of such rare DX on most bands, including on QRP frequencies.

Good news for amateurs, during a CQ WW not all DX create huge pileups and you have chance to be a handful of amateurs to work them. Some pileups are easier to work than usually because all amateurs are spread on all bands and a weak signal has more chance to be hear from the operator. This situation is still better when propagation is open with a low K-index.

All bands top winners CQ WW SSB contests

Cat.\Year

2014

2010

2000

1990

1980 1970

Single Op-All bands

8P5A CR2X HC8A CT3BH EA8AK W2SKE

Low Power

ZF2DX HI3TEJ P40P - - -

QRP

VE3VN KR2Q P40W KR2Q G4BUE -

Assisted

LX7I ER0WW A61AJ K1ZM - -

Multi Op-Single TX

CN2AA D4C P3A IQ4A I4RYC W6YY

Multi Op-Multi TX

CN3A EF8R CN8WW PJ1B PJ2CC DK0WA

Note that we find almost the same stations in CW mode. During a CQ WW, the fastest single operators are able to work up to 8655 stations (an average of 3 QSOs per minute in SSB in taking into account eating and sleeping time) as much as multi-operator teams or DX-peditions ! Difficult to break their record !

This contest like the others deserve your attention, that you are SWL or licensed amateur. This is like suddenly world-wide, all amateurs woke up and work on the air for the greatest pleasure of the ham communtity.

Usually there are interesting openings on all bands. In fact, most licensed amateurs take advantage of this fall week-end not only to win the contest, what becomes very hard, but first of all to complete their DXCC palmares. It is at such occasions that you can confirm new entities located over 10000 km away and closer countries in new bands.

To get the honor place, advanced amateurs do not hesitate to calculate their chance to get a QSO thanks to near-real-time propagation data and to set up for this special event a large beam.

Unfortunately, a SWL often uses a smaller antenna like a dipole or a small vertical well unable to capture the weakest signals. We will take time to go further in this question in other pages dealing with antennas.

DX atlases to download

(more software are listed in the download page)

DX Atlas 1.2 (1.2 MB ZIP file)

DXAtlas 2.0 by AA6YQ (3 MB ZIP file)

Chasing DXers

You can also search for amateurs calling "CQ DX" or calling for a specific continent, ocean or country (CQ Pacific, Asia, Japan...) and be in alert to catch all QSOs just "behind" them. Of course amateurs using special prefixes are still more interesting as they attract still more amateurs.

In the past for example, with the help of TU2IG I was able to record in summer at around 2100 UTC, when the propagation was not disturbed by the Sun activity, dozen of JA stations, an opportunity to increase my score for the japanese awards. Another time the Belgian operator OP1A allowed me to hear many South America stations. At last, with the help of 4S7AB who worked on the 17 m band around 1900 UTC I heard many US amateurs who helped me to increase my score for the US county award.

Listen to DX-peditions is very exciting if you can hear them. From statistics, we can say that working on all HF bands and several modes with 8 operators for example such teams can easy work 40 CQ zones and about 150 DX entities in a week whereas a SWL working alone needs over 3 months of active listenings to achieve such a score.

Check DX spots on clusters : DXHeat - HB9DRV - DX Summit

LOTW Online - DXMaps - Ham Radio Deluxe - eHam

Percentage of QSOs worked and listened per continent. In blue the results of S05X DX-pedition that worked over 31000 QSOs in four days in 2003. The curve displays my result as SWL with more than 3000 reports sent in one year of activity. Both curves are globally similar with few amateurs calling from outside Europe and North America. Asia is mainly represented by Russia and in a lesser extent by Japan, then comes Middle East countries. This is of course not surprising that North America comes in second place after Europe when we know that more than half of radio amateurs live in the U.S.A.

For sure such a solution has some limits. An european amateur using a 2-element quad and 1 kW PEP will reach VK and JA stations with ease even if the band is so-called closed for all other amateurs working barefoot with only 100 watts PEP. This DXer is probably not the best example to follow if you like hamradio, and in all cases if you hear him you will surely not hear his contacts...

The holidays

Before closing this long list of DX opportunities, recall that the holidays and specially the summer time is also an excellent period to hear or work DX stations.

Indeed, many amateurs go abroad with a portable transceiver in their luggages, and many DX-peditions wait for the summer to plan their activity. So compared to the usual business days, you have much more chances to hear or work rare DX stations during the holidays where the working conditions explained before apply too (to work with the gray line, etc).

At last, there are also much more regional activities, including some rare activations (e.g. special events) during sunny days, specially during the weekends where all bands are practically crowded with special call signs.

HF bands specially crowded a weekend at daytime end June 2015.

10% of stations listed on clusters worked portable, some from abroad and from rare DX.

Working with DX clusters

To be sure to pick up (almost) all amateurs stations "passing near" and put all chances on your side to add a DX station or a special call sign to your palmares, it is very useful to read  for example news about current QSOs and DX-peditions, the ones to come, and to log their period of activity in your logger calendar in order to be alerted once they will be QRV. Your national ham radio magazine, and webzines like 425 DX Network can provide you such an information and much more.

Drawback of this solution, when printed, this information is not available in real-time. Can you, just now, tell me what DX-pedition or far DX should be actually in QSO on the 15m band, in SSB mode, and what is his QSL info ? Without network connection, it will be hard to get the answer.

So, to fill this gap since the late 1980s, we can access to the information available on packet radio clusters, and since the end of 1990s to Internet clusters like DX Summit, HB9DRV, and more recently LOTW and DXHeat (that is linked to WebSDR) among other web clusters.

Note that using "DX Summit", in clicking on a DX call sign, the application displays propagation conditions thanks to a VOACAP module (as does HamQTH too) while "DXHeat" displays by default a summary of propagation for the five continents and HF bands.

Listen to HF stations via DXHeat linked to WebSDR

clic on a DX call sign then select the headset

The two means to connect to a cluster to get DX spots and other annoucements in real-time for all bands. At left, the web cluster DXHeat. This interface displays not only the last DX on all frequencies but also conditions on bands, propagation conditions, and when you clic on a DX call sign and select the headset, you can listen to the frequency via a webSDR and access to QRZ database. At right, like most loggers, DX4WIN includes a packet interface (right windows) to connect to DX clusters using either a packet connection via a TNC or a Telnet (Internet) connection. Only restriction, the access to a DX cluster in packet or via Telnet requires a valid call sign (neither SWL or nickname) to login while the Internet access (e.g. to DXHeat) is public. However, it also requires a call sign to submit a DX spot.

Today this technology is largely widespread in the ham community at a point where amateurs can practically no more ignore this tool when they work on the air as it provides them a very useful assistance, including during contests.

Thanks to clusters, you can quickly identify a new station, and access online to huge databases of QSOs and hams related information saved on remote servers. Clusters allow you to talk to other amateurs for free, to sked QSOs or to request information to the ham community if necessary.

If you are interested to work with packet radio, I suggest you to read the page cluster and packet radio.

Completed with the latest DX-peditions, the last conditions of propagation (WWV) and the status of the space weather, with all these techniques and data at your disposal, you can no more say that you have no information about HF conditions and activities ! With all these tools in hand you should be able to work at your best on bands and break through all pileups, hearing practically all DX if you like that.

73 and Good DX !

Back to Menu

Page 1 - 2 - 3 -


Back to:

HOME

Copyright & FAQ