Sunday, May 13, 2012



Split Operation & How to Be Heard in a Pileup.

What is working split and why would I want to do it?
Working split is simply transmitting and receiving on two different frequencies. Many DX contacts are made by calling the DX station on his own frequency and listening for his reply. Transmitting and receiving on the same frequency is called working “simplex.” That works fine unless a large number of stations start calling the DX station. That will almost certainly happen with a truly rare DX station. Everybody wants to work him. Once a bunch of stations get calling it becomes impossible to hear him respond to anyone because the callers are transmitting on top of him. And they probably are a lot stronger than he is!

What is the solution? When this situation begins, a good DX operator will announce that he is going to “work split” and that he will listen on another frequency and not on his own. That is usually done simply by saying something like “listening up 5” or on CW “up 5” or “U5.” That means that you should call him not on his own frequency, but 5 khz above him.

Before we go further, here is a very short history lesson. Before the late 1960’s, and for a lot longer for many hams, a station consisted of a separate transmitter and receiver. The HF transceiver didn’t exist until then. With separate units it was very easy to transmit and receive on two different frequencies. In fact the issue was to get your transmitter set to the same frequency that you were receiving on!
Working split, especially on phone was common. At first when the transceiver came into existence the split capability was lost. The transmitter and receiver tracked each other. Very convenient for normal work, but a real step backwards for some DXing. To regain the loss, it was necessary to purchase an outboard VFO that would give the rig two VFOs that would operate independently and once again allow split capability. Some transceivers simply couldn’t do it. Luckily for us all modern transceivers have the capability to work split within a band. Most rigs use two digital VFOs called “A” and “B.” One VFO is set to the DX station’s frequency and the other one to your desired transmit frequency. Simple. See your radio’s instruction manual for how to do it. The most desirable set up, however is to have what is called a “sub‐receiver.” That gives you the capability to transmit on one frequency, to receive on that same frequency, and at the same time to receive on another frequency.  We will talk about how to use this in a minute. One more important point before we go on. Having the DX station listening on one frequency and transmitting on another allows you to hear him answer calls without interference from the callers. The same is not necessarily true at the DX end. Again, many stations may be calling on the same frequency clobbering each other. In that case the DX station should spread them out frequency wise by now saying “listening up 5 to 10.” You pick a spot in that range to call and hopefully the DX station can now separate out the callers. Elementary so far. Now this is where skill gets involved.

How do I make myself heard in a pileup?
The simple answer is to transmit in the clear from your competitors! Detecting patterns in how the DX operator responds to callers is invaluable. More on that later. Of course you have to make your call sign understandable to the DX station. On simplex it is difficult to ever be in the clear once multiple stations start calling. If you listen carefully, however, you may be able to time your calls between the other callers.  That may let you through. Use clear phonetics on phone and a clear “fist” on CW. Be brief.
Give your call once and then listen. If the DX station does not answer anyone try again. The loudest station may well win out on simplex, but not always. The guy in the clear when he sends his call will be heard best. Unless the pileup grows, you will get your turn as the competition thins out. On simplex, gentlemen may give each other a momentary clear shot and then send their call expecting the same in return. That’s nice, but it usually doesn’t happen. / Some inexperienced DX operators answer the last person who called. That station was probably in the clear, but this sets a bad precedent. Once a DX station starts doing this the callers go longer and longer trying to be the last one to transmit. The result is usually someone transmitting over the DX station. Sometimes they don’t listen for two or three quick QSOs that go on underneath them. / After listening for a while, and detecting a pattern with the DX operators behavior, you may have no choice except to try and be the last one calling. This really is poor procedure, but it might work. Don’t be ridiculous about it. Give the poor guy a chance to answer. A competent DX operator won’t let this happen and will go split. One more thing. If the DX station comes back with a partial call, like “The Whiskey 7, go ahead” or on CW “W7?” Don’t call again if you are not a W7!

Now it is time to talk about more advanced skills. Like I said above ‐ listening to the DX station and detecting patterns is invaluable. Once a pileup goes into split mode skill becomes more important than shere signal strength. Again, you goal is to transmit in the clear. If the split has gone beyond a single frequency, like the “5 to 10 up” scenario, transmitting where the DX is actually listening becomes key. Just blaring away on a set spot might work, but it might not. The idea is to find where the DX is listening or to anticipate where he will listen next. With most transceivers, to do this you must switch your radio’s VFOs to use the receiver to try and find the station that just connected with the DX. With a normal rig this requires jumping back and forth between receiving on VFO A and VFO B to hear the DX station and also search for the guy he is in contact with. This can be tricky and if you are not careful you may end up transmitting on the DX station’s transmit frequency by mistake. We have all done it, but you look like a real lid. In many cases the DX will hear you call on the same frequency that the last successful station used. Give it a try. You won’t be the only one who figures this out. Other experienced operators will be doing the same thing. Others will be trying to find the station in contact with the DX and then calling on the same frequency as the successful one too. If a pileup gets very large the spread may go much wider, especially on phone. In that case figuring out where to transmit becomes paramount. Calling on the last station’s frequency may not work. Keep listening. See if another station on that frequency was successful or if the DX gave his VFO a spin to again spread things out. If you hear another success story on the same frequency, try again. If you don’t, search again for the station that made it through. Try to detect a pattern. You may well see that each successive contact goes up a little in the band. In that case set yourself up a little above the last guy that was successful and try there. Keep working on finding a pattern. Some guys will list the frequency that worked for them on the DX cluster. That can be useful, but everyone in the world sees it and tries that frequency.
If you cannot determine a pattern or hear the other stations that are calling (which sometimes happens on the higher bands) then pick a freq and call. If no luck you can either move a little and try again or just keep on with your original freq. In this situation getting through becomes partly blind luck.

As I mentioned earlier, some transceivers have a built in advantage in working split. They have a sub receiver that allows you to listen to the DX station on his frequency and search for the callers at the same time on another frequency. This can be very valuable, but it is not absolutely necessary. Radios like the Yaesu FT1000/FT2000 series have true sub receivers. The Elecraft K3 has an option to add a sub receiver.    The top of the line Icoms like the IC7800 also have a sub. Many other Icom radios have what Icom calls “dual watch.” It isn’t exactly a sub receiver, but it does allow you to listen to two frequencies at once. A transceiver with a true sub receiver normally sends the audio from each of its receivers to your headphones separately in “stereo.” Dual watch puts the two signals together into both ears. Not quite as good, but still useful.   You are using headphones by now aren’t you?

The key to pileup busting is more than shere power. Many times it requires skill. Try out the ideas that I
gave you here. Your success rate will improve.

DX Propagation Basics:  
Propagation is a real science and cannot possibly be covered completely in a short chapter. I do hope, however, to give the new DXer some basics in understanding how it all works and that understanding will improve your odds of making great DX contacts.

First a little very basic theory: Above what we normally think of as the Earth’s atmosphere are four layers of ionosphere. If you will think back to your high school chemistry an ion is an atom that is missing an electron or the free electron itself. This occurs in the ionosphere by the Sun’s radiation beating down on those upper layers and jolting individual atoms to give up a free electron. These ions make a very conductive layer wherever this occurs.

The ionosphere has three basic layers designated by the letters “D”, “E” and “F”. The “F” layer is broken down into two sub layers called the “F1” and “F2” layers. The D layer is closest to the Earth at a lower altitude than the E layer which is lower than the F1 and finally the F2 layer. Radio signals may be either reflected or absorbed in the ionosphere. The level of ionization is determined by many factors all related to the Sun.   Radio waves of different wavelengths are impacted differently by the ionosphere. Shorter wavelengths (higher frequencies) penetrate deeper into the ionosphere than longer wavelengths (lower frequencies.) This makes for radically different propagation depending on a radio wave’s frequency. During the daylight hours the D layer forms at a relatively low altitude. It mostly acts as an RF sponge. The longer wavelengths are soaked up by it during the day. The D layer disappears at night. That is why standard AM radio has very limited range during the day, but may go great distances at night by reflecting off of one of the higher layers. Conversely, UHF and VHF frequencies normally penetrate all of the layers and shoot out into space, never to return to Earth.  During daylight the higher HF ham bands can penetrate the D layer and then are reflected by the F layer. At night the lower bands are reflected by the F layer, but the F layer may not be ionized densely enough to reflect the higher bands.  Once again those signals blast out into space. When the Sun is directly overhead (local noon) sometimes there is enough energy to ionize the “E” layer. This is especially true at the summer solstice when the Sun’s rays are coming in at a higher angle than in the winter months. At that time, the E layer can be very densely ionized. Sometimes this ionization can be so dense that it will reflect VHF signals like 6 M.

The bottom line of all this is that the lower bands are open at night and the higher bands during daylight. The 20 M band is in the middle and can be open anytime. Actually, all of the higher bands can be open at night depending on the level of the Sun’s activity.  Radio waves propagate around the world by bouncing between the ionosphere and the Earth. Multiple hops occur in long distance communications. Sea water is much more reflective than dirt. Therefore paths that transverse the oceans are more favorable than land paths. Each hop causes signals to decrease.

Enough of the theory. Now the practical stuff!  Everyone knows that the shortest distance between two points is a straight line. That is the path that radio signals normally follow. That route is called the “short path.” If you grew up looking at the maps in school you probably learned a very distorted view of the world. Those maps are usually a Mercator Projection which distorts the extreme north and south polar regions. It is also misleading that those maps give you the picture that Europe is almost due east of the USA, that India is just further east and that South Africa is south east. That just isn’t true. No flat map can represent the round Earth accurately in all respects. That can only be done with a round globe. If you put a string between those distant points on a globe and the USA you get a true bearing that is called a “great circle” route. The great circle is the real direction to distant points.  Your beam antenna won’t work well unless it is pointed in the right direction! Here is a free source to compute the actual beam headings for your individual QTH.‐tools/beam‐headings.php . I have put a chart at the end of this handbook for my location as a sample. If you live within a few hundred miles of my QTH it should be accurate enough. If you don’t, then just use the link above to generate one for you exact location. Also, see below an azimuth map centered on Utah. The program to create this map is available as freeware at . Download from this site and install it. It is a very nice free program. There are many other programs available on the web to compute azimuth maps. The ARRL sells a very nice azimuth wall map that I own. See .

From the map below you can see that Europe is north‐north‐east from us, and not due east. England is at 38 degrees, over the north polar region. India is actually nearly due north at 348 degrees, directly over the North Pole. South Africa is almost due east at 97 degrees, far from the south east bearing that the Mercator map suggests.

As I mentioned earlier this is the “short path” to distant locations and usually radio waves follow that most direct path. Note that I said usually. It is very common for signals from the most distant locations to go the other way around the Earth. This happens on different bands because of daylight or night paths.  In our early morning the Earth is dark to our west. The 40 M band works best at night. Therefore by sending your signal into the darkness it just might propagate around the entire dark half of the Earth and come out at the sunset end of the dark path – on the other side of the world! During the winter it is common to work Europe via this “long path” on 40 M. The “long path” is exactly 180 degrees from the azimuth shown on our map.  Don’t count yourself out just because you don’t have a beam antenna. I only have vertical on 40 M, but knowing that something good might come in via the long path is still useful. In the mornings look for propagation over the dark side of the Earth to our west.

The Indian Ocean is located at the most distant point on the planet from us (antipode). The outermost circle on an azimuth map is actually a single point in the Indian Ocean. Notice that this point is the same distance no matter what heading we use. What I’m getting at is that signals from the Indian Ocean may arrive from any direction!  Most of the time a signal will come either via the short path or the 180 degree opposite long path. Once in a while this isn’t true. Odd propagation via a “crooked path” sometimes occurs. By this I mean that you find that your beam peaks in a direction that is neither the short or long path. It does happen. Sometimes signals get bent around the aurora zone at the poles. Other times a highly ionized spot occurs directly under the Sun that has nothing to do with either regular path. In these cases it may be possible to do a “bank shot” (just like in pool) to get to a remote location when no direct propagation is possible. An excellent example of this sometimes happens over the Atlantic Ocean. You can’t hear Europe at north‐north‐east, but you can at south east!  This usually happens on the higher bands like 15M.

It has been said that “there is no such thing as a free lunch.” One special case in HF propagation comes close. There is a big enhancement in propagation particularly at sunrise, but also at sunset. During that time of twilight something wonderful happens and it has nothing to do with werewolves. Along that line between daylight and darkness enhanced propagation often occurs. Watch out for this. As the so called “grey line” passes over us good things happen. This can be very useful in working other locations along that boundary, but only for a short time. I have made some of my very best contacts along that line into the Indian Ocean using this mode. By plotting where the grey line occurs at other places on the Earth, you can also frequently predict signal peaks from DX stations. This peak may still occur when their grey line does not run over our location. Always keep an eye open for good things to happen over the grey line.

My point to all of this is to make you aware that signal propagation is kind of fickle. Weird things also happen through “ducting” and other odd phenomena that are too complicated for this short chapter. Just remember to use your azimuth map to aim your beam and don’t forget the long path and the grey line. The Indian Ocean is a wild card and so is crooked path propagation!

Propagation prediction is very difficult to do. There are, however, some basic indicators that help. Scientists are always tracking what is happening with the Sun. Without getting complex there are three very useful parameters to use to predict band conditions. They are solar flux and the “A” and “K” indexes. The higher the solar flux the better. It has been very low for years! The lower the A and K indexes the better. They indicate activity in the Earth’s geomagnetic field. When the geomagnetic field gets agitated by the Sun, propagation degrades. See this site for lots of information on this science: and if you want even more information check out

The International Amateur Radio Union represents amateur radio’s interests world wide.  Each member country has a representative organization within the IARU. Ours is the ARRL. The IARU has established
a “beacon network” to research HF propagation. The network consists of automated stations in several locations around the world that transmit on a closely synchronized schedule. The beacons operate on frequencies of: 14.100, 18.110, 21.150 and 24.930 Mhz.  By monitoring these frequencies it is easy to detect band openings to the various beacon locations.
See: for general information on the beacon project. See: for articles on the beacon system. Check this out!

Propagation prediction programs:
The U. S. government has spent enormous amounts of time and money in creating a very accurate modeling program for predicting HF propagation. This software (VOACAP) is freeware from the U. S. government, but it is cumbersome to use without some sort of an interface program. In the past I have used VOAProp. See: . This program is very useful and also free!  The VOAProp web site has a link to obtain your free copy of the VOACAP calculation engine that is required to drive VOAProp.  As an added useful feature, VOAProp will also show you which IARU beacon is transmitting at that instant! It is well worth the effort to install this software.

After using VOAProp for several years, I recently upgraded to a more advanced suite of programs written by VE3NEA ‐ (the same guy who provides CW Skimmer) .  See: . This suite consists of four separate programs that work together. The combined cost is about $75.00, but the capabilities surpass VOAProp in how well the data is presented and they also have additional useful features. However, both VOAProp and DX Atlas use exactly the same underlying U. S. government software calculation engine. Therefore, the free one is just as accurate as the expensive one. DX Atlas just presents the data in a fancier format.

Some of our club members like another free propagation prediction program, W6EL Prop. See: . This program has a wealth of options to present the prediction data in the form of maps or in numeric/tabular form. Since it is also free, why not get a copy and try it out?

There is also a brand new free online propagation prediction service that uses Google Maps to specify the exact locations for the transmitter and receiver sites. It is called VOACap Online. See: . Once the path end points are specified, the online display then shows a color graph of times and frequencies with probabilities of success for communications between the two locations. Very nice.

Any of these propagation prediction programs will give you very useful data.  I highly recommend that every DXer obtain access to some form of accurate propagation prediction data.  With multiple free sources, why not get copies of all of them and see what works best for you?

Once you have a good understanding of propagation it will certainly improve your odds of working more DX!

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